ENERGY CO OF MINAS GERAIS (SEC Filing Page | XBRL Cloud Viewer | XBRL Instance)

Line Label Object Class Period Type Balance Report ElementName
1 1001 - Document - Document and Entity Information Network

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 http://imetrix.edgar-online.com/taxonomy/role/DocumentandEntityInformation
2 Implied Table Table

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3 Document - Document and Entity Information [Abstract] Abstract xcmig:DocumentandEntityInformationAbstract
4 Document Type Concept (Submission Type) For Period dei:DocumentType
5 Amendment Flag Concept (Yes/No) For Period dei:AmendmentFlag
6 Document Period End Date Concept (Date) For Period dei:DocumentPeriodEndDate
7 Document Fiscal Year Focus Concept (Year) For Period dei:DocumentFiscalYearFocus
8 Document Fiscal Period Focus Concept (Fiscal Period) For Period dei:DocumentFiscalPeriodFocus
9 Trading Symbol Concept (Text/String) For Period dei:TradingSymbol
10 Entity Registrant Name Concept (Text/String) For Period dei:EntityRegistrantName
11 Entity Central Index Key Concept (CIK Number) For Period dei:EntityCentralIndexKey
12 Current Fiscal Year End Date Concept (Month/Day) For Period dei:CurrentFiscalYearEndDate
13 Entity Well-known Seasoned Issuer Concept (Yes/No) For Period dei:EntityWellKnownSeasonedIssuer
14 Entity Current Reporting Status Concept (Yes/No) For Period dei:EntityCurrentReportingStatus
15 Entity Filer Category Concept (Filer Category) For Period dei:EntityFilerCategory
16 Entity Common Stock, Shares Outstanding Concept (Shares) As Of dei:EntityCommonStockSharesOutstanding
17 1003 - Statement - Consolidated Statement of Financial Position Network

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 http://imetrix.edgar-online.com/taxonomy/role/StatementOfFinancialPositionCurrentNonCurrent-210000
18 Statement [Table] Table

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 us-gaap:StatementTable
19 Classes of financial liabilities [axis] Axis ifrs-full:ClassesOfFinancialLiabilitiesAxis
20 Financial liabilities, class [member] Member ifrs-full:FinancialLiabilitiesMember
21 Put options [member] Member xcmig:PutOptionsMember
22 Swaps [member] Member xcmig:SwapsMember
23 Statement [Line Items] LineItems us-gaap:StatementLineItems
24 CURRENT Abstract ifrs-full:CurrentAssetsAbstract
25 Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
26 Securities Concept (Monetary) As Of Debit xcmig:ShortTermSecurities
27 Customers and traders and Concession holders - Transport of electricity Concept (Monetary) As Of Debit xcmig:CurrentCustomersAndTradersAndConcessionHoldersTransportOfElectricity
28 Concession financial assets Concept (Monetary) As Of Debit ifrs-full:CurrentFinancialAssets
29 Recoverable taxes Concept (Monetary) As Of Debit xcmig:CurrentRecoverableTaxes
30 Income and social contribution tax credits Concept (Monetary) As Of Debit xcmig:CurrentIncomeAndSocialContributionTaxCredits
31 Dividends receivable Concept (Monetary) As Of Debit xcmig:CurrentDividendsReceivable
32 Restricted cash Concept (Monetary) As Of Debit ifrs-full:RestrictedCashAndCashEquivalents
33 Inventories Concept (Monetary) As Of Debit ifrs-full:Inventories
34 Advances to suppliers Concept (Monetary) As Of Debit ifrs-full:CurrentAdvancesToSuppliers
35 Accounts Receivable from the State of Minas Gerais Concept (Monetary) As Of Debit ifrs-full:TradeAndOtherCurrentReceivables
36 Reimbursement of tariff subsidies Concept (Monetary) As Of Debit xcmig:ReimbursementOfTariffSubsidies
37 Low-income subscriber subsidy Concept (Monetary) As Of Debit xcmig:LowIncomeSubscriberSubsidy
38 Receivable from Eletrobras Concept (Monetary) As Of Debit ifrs-full:NoncurrentReceivablesDueFromRelatedParties
39 Other Concept (Monetary) As Of Debit ifrs-full:OtherCurrentAssets
40 TOTAL, CURRENT Concept (Monetary) As Of Debit ifrs-full:CurrentAssets
41 NON-CURRENT Abstract ifrs-full:NoncurrentAssetsAbstract
42 Securities Concept (Monetary) As Of Debit xcmig:LongTermSecurities
43 Advance to suppliers Concept (Monetary) As Of Debit xcmig:NoncurrentAdvancesToSuppliers
44 Customers and traders and Concession holders - Transport of electricity Concept (Monetary) As Of Debit xcmig:NoncurrentCustomersAndTradersAndConcessionHoldersTransportOfElectricity
45 Recoverable taxes Concept (Monetary) As Of Debit xcmig:NoncurrentRecoverableTaxes
46 Income and Social Contribution taxes recoverable Concept (Monetary) As Of Debit xcmig:NoncurrentIncomeAndSocialContributionTaxesRecoverable
47 Deferred income and Social Contribution taxes Concept (Monetary) As Of Debit xcmig:DeferredIncomeTaxAssetsAndSocialContributionTaxNoncurrent
48 Escrow deposits Concept (Monetary) As Of Debit xcmig:LongTermEscrowDeposit
49 Derivative financial instruments - Swaps Concept (Monetary) As Of Debit ifrs-full:NoncurrentDerivativeFinancialAssets
50 Other credits Concept (Monetary) As Of Debit xcmig:NoncurrentOtherCredits
51 Concession financial assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssets
52 Investments - Equity method Concept (Monetary) As Of Debit ifrs-full:InvestmentAccountedForUsingEquityMethod
53 Property, plant and equipment Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
54 Intangible assets Concept (Monetary) As Of Debit ifrs-full:IntangibleAssetsOtherThanGoodwill
55 TOTAL, NON-CURRENT Concept (Monetary) As Of Debit ifrs-full:NoncurrentAssets
56 Total assets Concept (Monetary) As Of Debit ifrs-full:Assets
57 CURRENT Abstract ifrs-full:CurrentLiabilitiesAbstract
58 Suppliers Concept (Monetary) As Of Credit ifrs-full:TradeAndOtherCurrentPayablesToTradeSuppliers
59 Regulatory charges Concept (Monetary) As Of Credit xcmig:CurrentRegulatoryLiability
60 Profit sharing Concept (Monetary) As Of Credit xcmig:CurrentLiabilitiesFromProfitSharing
61 Taxes payable Concept (Monetary) As Of Credit ifrs-full:CurrentTaxLiabilitiesCurrent
62 Income and Social Contribution tax Concept (Monetary) As Of Credit ifrs-full:CurrentPayablesOnSocialSecurityAndTaxesOtherThanIncomeTax
63 Interest on equity and dividends payable Concept (Monetary) As Of Credit xcmig:InterestOnEquityAndDividendsPayableCurrent
64 Loans, financings and debentures Concept (Monetary) As Of Credit ifrs-full:ShorttermBorrowings
65 Payroll and related charges Concept (Monetary) As Of Credit xcmig:PayrollAndRelatedCharges
66 Post-retirement obligation Concept (Monetary) As Of Credit ifrs-full:CurrentRecognisedLiabilitiesDefinedBenefitPlan
67 Concessions payable Concept (Monetary) As Of Credit xcmig:CurrentConcessionsPayable
68 Concession financial liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentFinancialLiabilities
69 Derivative financial Instruments Concept (Monetary) As Of Credit ifrs-full:CurrentDerivativeFinancialLiabilities
70 Advances from clients Concept (Monetary) As Of Credit ifrs-full:CurrentAdvances
71 Other obligations Concept (Monetary) As Of Credit ifrs-full:OtherCurrentLiabilities
72 TOTAL, CURRENT Concept (Monetary) As Of Credit ifrs-full:CurrentLiabilities
73 NON-CURRENT Abstract ifrs-full:NoncurrentLiabilitiesAbstract
74 Regulatory charges Concept (Monetary) As Of Credit xcmig:NoncurrentRegulatoryLiability
75 Loans, financings and debentures Concept (Monetary) As Of Credit ifrs-full:LongtermBorrowings
76 Taxes payable Concept (Monetary) As Of Credit ifrs-full:CurrentTaxLiabilitiesNoncurrent
77 Deferred income tax and Social Contribution tax Concept (Monetary) As Of Credit xcmig:NoncurrentPayablesOnSocialSecurityAndTaxes
78 Provisions Concept (Monetary) As Of Credit ifrs-full:NoncurrentProvisions
79 Post-retirement obligation Concept (Monetary) As Of Credit ifrs-full:NoncurrentRecognisedLiabilitiesDefinedBenefitPlan
80 Concessions payable Concept (Monetary) As Of Credit xcmig:NoncurrentConcessionsPayable
81 Concession financial liabilities Concept (Monetary) As Of Credit ifrs-full:NoncurrentFinancialLiabilities
82 Pasep and Cofins taxes to be reimbursed to customers Concept (Monetary) As Of Credit xcmig:PasepAndCofinsTaxesToBeReimbursedToCustomers
83 Derivative financial Instruments Concept (Monetary) As Of Credit ifrs-full:NoncurrentDerivativeFinancialLiabilities
84 Other obligations Concept (Monetary) As Of Credit ifrs-full:OtherNoncurrentLiabilities
85 TOTAL, NON-CURRENT Concept (Monetary) As Of Credit ifrs-full:NoncurrentLiabilities
86 Total liabilities Concept (Monetary) As Of Credit ifrs-full:Liabilities
87 EQUITY Abstract ifrs-full:EquityAbstract
88 Share capital Concept (Monetary) As Of Credit ifrs-full:IssuedCapital
89 Capital reserves Concept (Monetary) As Of Credit ifrs-full:CapitalReserve
90 Profit reserves Concept (Monetary) As Of Credit ifrs-full:RetainedEarnings
91 Equity valuation adjustments Concept (Monetary) As Of Credit xcmig:EquityValuationReserve
92 Deemed cost of property, plant and equipment Concept (Monetary) As Of Credit xcmig:DeemedCostOfPropertyPlantAndEquipmentReserve
93 Accumulated Other Comprehensive Income Concept (Monetary) As Of Credit ifrs-full:AccumulatedOtherComprehensiveIncome
94 Subscription of Shares, to be Capitalized Concept (Monetary) As Of Credit xcmig:SubscriptionOfSharesToBeCapitalized
95 EQUITY ATTRIBUTABLE TO EQUITY HOLDERS OF THE PARENT Concept (Monetary) As Of Credit ifrs-full:EquityAttributableToOwnersOfParent
96 NON-CONTROLLINGINTERESTS Concept (Monetary) As Of Credit ifrs-full:NoncontrollingInterests
97 TOTAL EQUITY Concept (Monetary) As Of Credit ifrs-full:Equity
98 TOTAL LIABILITIES AND EQUITY Concept (Monetary) As Of Credit ifrs-full:EquityAndLiabilities
99 1004 - Statement - Consolidated Statement of Income Network

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 http://imetrix.edgar-online.com/taxonomy/role/StatementOfComprehensiveIncomeProfitOrLossByFunctionOfExpense-310000
100 Statement [Table] Table

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 us-gaap:StatementTable
101 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
102 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
103 Preferred shares [member] Member xcmig:PreferredSharesMember
104 Common shares [member] Member xcmig:CommonSharesMember
105 Statement [Line Items] LineItems us-gaap:StatementLineItems
106 NET REVENUE Concept (Monetary) For Period Credit ifrs-full:Revenue
107 OPERATING COSTS Abstract xcmig:OperatingCostAndExpenseAbstract
108 COST OF ENERGY AND GAS Abstract xcmig:CostOfEnergyAndGasAbstract
109 Energy purchased for resale Concept (Monetary) For Period Debit xcmig:EnergyPurchasedForResale
110 Charges for the use of the national grid Concept (Monetary) For Period Debit xcmig:NationalGridUsageCharges
111 Gas purchased for resale Concept (Monetary) For Period Debit xcmig:GasPurchasedForResale
112 Cost of purchased energy sold Concept (Monetary) For Period Debit ifrs-full:CostOfPurchasedEnergySold
113 OTHER COSTS Abstract xcmig:OtherCostAbstract
114 Personnel and managers Concept (Monetary) For Period Debit xcmig:PersonnelAndManagers
115 Materials Concept (Monetary) For Period Debit xcmig:MaterialCost
116 Outsourced services Concept (Monetary) For Period Debit ifrs-full:ServicesExpense
117 Depreciation and amortization Concept (Monetary) For Period Debit ifrs-full:DepreciationAndAmortisationExpense
118 Operating provisions, net Concept (Monetary) For Period Debit xcmig:OperatingCostProvisions
119 Infrastructure construction cost Concept (Monetary) For Period Debit xcmig:InfrastructureConstructionCost
120 Other Concept (Monetary) For Period Debit ifrs-full:OtherExpenseByNature
121 Other costs Concept (Monetary) For Period Debit xcmig:OtherCosts
122 TOTAL COST Concept (Monetary) For Period Debit ifrs-full:CostOfSales
123 GROSS PROFIT Concept (Monetary) For Period Credit ifrs-full:GrossProfit
124 OPERATING EXPENSES Concept (Monetary) For Period Debit ifrs-full:OperatingExpense
125 Selling expenses Concept (Monetary) For Period Debit ifrs-full:SalesAndMarketingExpense
126 General and administrative expenses Concept (Monetary) For Period Debit xcmig:GeneralAndAdministrativeExpense2
127 Operating provisions Concept (Monetary) For Period Credit xcmig:OperatingExpenseProvisions
128 Other operating revenues (expenses) Concept (Monetary) For Period Credit ifrs-full:OtherOperatingIncomeExpense
129 Operating expense Concept (Monetary) For Period Debit ifrs-full:OperatingExpense
130 Share of (loss) profit, net, of associates and joint ventures Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
131 Impairment loss on Investments Concept (Monetary) For Period Debit ifrs-full:ImpairmentLossRecognisedInProfitOrLossTradeReceivables
132 Fair value gain on shareholding transaction Concept (Monetary) For Period Credit xcmig:FairValueGainLossOnStockholdingTransaction
133 Income before finance income (expenses) and taxes Concept (Monetary) For Period Credit xcmig:IncomeBeforeFinancialIncomeExpensesAndTaxes
134 Finance income Concept (Monetary) For Period Credit ifrs-full:FinanceIncome
135 Finance expenses Concept (Monetary) For Period Debit ifrs-full:FinanceCosts
136 Income before income tax and social contribution tax Concept (Monetary) For Period Credit ifrs-full:ProfitLossBeforeTax
137 Current income and social contribution taxes Concept (Monetary) For Period Debit ifrs-full:CurrentTaxExpenseIncome
138 Deferred income and social contribution taxes Concept (Monetary) For Period Debit ifrs-full:DeferredTaxExpenseIncome
139 NET INCOME (LOSS) FOR THE YEAR Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromContinuingOperations
140 Total of net income for the year attributed to: Abstract ifrs-full:ProfitLossAttributableToAbstract
141 Equity holders of the parent Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToOwnersOfParent
142 Non-controllinginterests Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToNoncontrollingInterests
143 NET INCOME (LOSS) FOR THE YEAR Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromContinuingOperations
144 Basic earnings per preferred share - R$ Concept (Share) For Period ifrs-full:BasicEarningsLossPerShare
145 Basic earnings per preferred share - R$ Concept (Share) For Period ifrs-full:DilutedEarningsLossPerShare
146 1005 - Statement - Consolidated Statement of Comprehensive Income Network

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 http://imetrix.edgar-online.com/taxonomy/role/StatementOfComprehensiveIncomeOCIComponentsPresentedNetOfTax-410000
147 Implied Table Table

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 implied:Table
148 Statement of comprehensive income [abstract] Abstract ifrs-full:StatementOfComprehensiveIncomeAbstract
149 Net income for the year Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromContinuingOperations
150 OTHER COMPREHENSIVE INCOME Abstract ifrs-full:OtherComprehensiveIncomeAbstract
151 Items not to be reclassified to profit or loss in subsequent periods Abstract ifrs-full:ComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTaxAbstract
152 Post retirement liabilities - remesurement of obligations of the defined benefit plans, net of taxes Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeNetOfTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans
153 Equity gain (loss) on other comprehensive income in subsidiary and jointly-controlled entity, net of taxes Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeNetOfTaxGainsLossesFromInvestmentsInEquityInstruments
154 Other comprehensive income that will not be reclassified to profit or loss, net of tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax
155 Items to be reclassified to profit or loss in subsequent periods Abstract ifrs-full:ComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTaxAbstract
156 Equity gain on other comprehensive income, in subsidiary and jointly-controlled entity, relating to fair value of financial asset available for sale, net of tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeNetOfTaxAvailableforsaleFinancialAssets
157 Reclassification of translation adjustments to the Income statement arising from sale of Transchile Concept (Monetary) For Period Debit ifrs-full:ReclassificationAdjustmentsOnExchangeDifferencesOnTranslationNetOfTax
158 Other comprehensive income that will be reclassified to profit or loss, net of tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax
159 COMPREHENSIVE INCOME FOR THE YEAR Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncome
160 Total of comprehensive income for the year attributed to: Abstract ifrs-full:ComprehensiveIncomeAttributableToAbstract
161 Equity holders of the parent Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncomeAttributableToOwnersOfParent
162 Non-controllinginterests Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncomeAttributableToNoncontrollingInterests
163 COMPREHENSIVE INCOME FOR THE YEAR Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncome
164 1006 - Statement - Consolidated Statement of Changes in Equity Network

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 http://imetrix.edgar-online.com/taxonomy/role/StatementOfChangesInEquity-610000
165 Statement of changes in equity [table] Table

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 ifrs-full:StatementOfChangesInEquityTable
166 Components of equity [axis] Axis ifrs-full:ComponentsOfEquityAxis
167 Equity [member] Member ifrs-full:EquityMember
168 Share capital [member] Member xcmig:ShareCapitalMember
169 Capital reserves [member] Member ifrs-full:CapitalReserveMember
170 Profits reserves [member] Member xcmig:ProfitsReservesMember
171 Equity Valuation adjustments [member] Member xcmig:EquityValuationAdjustmentsMember
172 Retained earnings [member] Member ifrs-full:RetainedEarningsMember
173 Total interest of the controlling shareholders [member] Member ifrs-full:EquityAttributableToOwnersOfParentMember
174 Total interest of the non-controlling interests [member] Member ifrs-full:NoncontrollingInterestsMember
175 Subscription of shares, to be capitalized [member] Member xcmig:SubscriptionOfSharesToBeCapitalizedMember
176 Statement of changes in equity [line items] LineItems ifrs-full:StatementOfChangesInEquityLineItems
177 Beginning balance Concept (Monetary) As Of Credit ifrs-full:Equity
178 Net income for the year Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
179 Other comprehensive income Abstract ifrs-full:ComprehensiveIncomeAbstract
180 Remeasurement of obligations of the defined benefit plans, net of taxes Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeNetOfTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans
181 Remeasurement of obligations of the defined benefit plans, net of taxes Concept (Monetary) For Period Debit ifrs-full:PostemploymentBenefitExpenseDefinedBenefitPlans
182 Equity gain (loss) on Other comprehensive income in subsidiary and jointly-controlled entity Concept (Monetary) For Period Credit ifrs-full:OtherIncomeExpenseFromSubsidiariesJointlyControlledEntitiesAndAssociates
183 COMPREHENSIVE INCOME FOR THE YEAR Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncome
184 Subscription of shares, to be capitalized Concept (Monetary) For Period Credit xcmig:IncreaseDecreaseThroughSubscriptionOfSharesToBeCapitalized
185 Other changes in equity: Abstract ifrs-full:ChangesInEquityAbstract
186 Additional dividends proposed, non-controlling interests Concept (Monetary) For Period Credit xcmig:IncreaseDecreaseThroughDividendsProposed
187 Reserve for mandatory dividends not distributed Concept (Monetary) As Of Credit xcmig:ReserveForObligatoryDividendsNotDistributed
188 Dividends under the by-laws Concept (Monetary) For Period Credit xcmig:IncreaseDecreaseThroughStatutoryDividends
189 Interest on Equity Concept (Monetary) For Period Credit xcmig:IncreaseDecreaseThroughInterestOnEquity
190 Constitution of reserves Abstract xcmig:ConstitutionOfReservesAbstract
191 Tax incentives reserve Concept (Monetary) For Period Credit xcmig:IncreaseDecreaseThroughTaxIncentiveReserve
192 Appropriation of retain earnings to profit reserves Concept (Monetary) For Period xcmig:IncreaseDecreaseThroughRetainedEarningsReserve
193 Appropriation of retain earnings to profit reserves Concept (Monetary) For Period Credit xcmig:IncreaseDecreaseThroughProfitReserve
194 Realization of reserves Abstract xcmig:RealizationOfReservesAbstract
195 Realization of deemed cost of PP&E Concept (Monetary) For Period Credit xcmig:RealizationOfDeemedCostOfPropertyPlantAndEquipment
196 Ending balance Concept (Monetary) As Of Credit ifrs-full:Equity
197 1007 - Statement - Consolidated Statement of Changes in Equity (Parenthetical) Network

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 http://imetrix.edgar-online.com/taxonomy/role/StatementOfChangesInEquity-610000Parenthetical
198 Implied Table Table

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 implied:Table
199 Statement of changes in equity [abstract] Abstract ifrs-full:StatementOfChangesInEquityAbstract
200 Statutory dividends per share Concept (Share) For Period xcmig:StatutoryDividendPerShareDeclared
201 Interest on equity per share Concept (Share) For Period xcmig:InterestOnEquityPerShare
202 1008 - Statement - Consolidated Statement of Cash Flow Network

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 http://imetrix.edgar-online.com/taxonomy/role/StatementOfCashFlowsIndirectMethod-520000
203 Implied Table Table

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204 Statement of cash flows [abstract] Abstract ifrs-full:StatementOfCashFlowsAbstract
205 CASH FLOW FROM OPERATIONS Abstract ifrs-full:CashFlowsFromUsedInOperatingActivitiesAbstract
206 Net income for the year Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromContinuingOperations
207 Adjustments to reconcile net income to net cash flows: Abstract ifrs-full:AdjustmentsForReconcileProfitLossAbstract
208 Income tax and Social Contribution taxes Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForIncomeTaxExpense
209 Depreciation and amortization Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDepreciationAndAmortisationExpense
210 Loss on write off of net residual value of unrecoverable Concession financial assets , PP&E and Intangible assets Concept (Monetary) For Period Debit xcmig:AdjustmentsForNetResidualValueOfFinancialAssetsOfTheConcessionPropertyPlantAndEquipmentAndIntangibleAssets
211 Gain on sale of investments Concept (Monetary) For Period Credit xcmig:NetGainOnSaleOfInvestmentSecurities
212 Impairment of Investments Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLoss
213 Generation Indemnity Revenue Concept (Monetary) For Period Debit xcmig:AdjustmentsForGenerationIndemnityRevenue
214 Adjustment to BRR for transmission assets Concept (Monetary) For Period Debit xcmig:AdjustmentsToBRRForTransmissionAssets
215 Share of loss (profit) of associates and joint ventures Concept (Monetary) For Period Credit ifrs-full:AdjustmentsForGainLossOnDisposalOfInvestmentsInSubsidiariesJointVenturesAndAssociates
216 Interest and monetary variation Concept (Monetary) For Period Credit ifrs-full:AdjustmentsForInterestIncome
217 Appropriation of transaction costs Concept (Monetary) For Period Credit xcmig:AdjustmentsForAppropriationOfTransactionCosts
218 Gain in accounts receivable from the MG State Govt.-AFAC Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDecreaseIncreaseInTradeAccountReceivable
219 Fair value gain (loss) on shareholding transaction Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForFairValueGainsLosses
220 Provisions for operating losses Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForProvisions
221 Derivative financial instruments-Swap Concept (Monetary) For Period Debit xcmig:AdjustmentsForDerivativeFinancialInstrumentsSwap
222 CVA (Portion A items Compensation) Account and Other financial components in tariff adjustments Concept (Monetary) For Period Debit xcmig:AdjustmentsForCVAAccountAndOtherFinancialComponentsInTariffAdjustments
223 Tax Anmesty Program (PRCT) Concept (Monetary) For Period Debit xcmig:AdjustmentsForTaxAnmestyProgram
224 Post-retirement obligation Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForIncreaseDecreaseInEmployeeBenefitLiabilities
225 Total Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForReconcileProfitLoss
226 (Increase) / decrease in assets Abstract xcmig:AdjustmentsForDecreaseIncreaseInAssetsAbstract
227 Customers and traders and Concession holders - Transport of electricity Concept (Monetary) For Period Debit xcmig:AdjustmentsForDecreaseIncreaseInCustomersAndTradersAndConcessionHoldersTransportOfElectricity
228 Accounts Receivable from the State of Minas Gerais Concept (Monetary) For Period Debit xcmig:AdjustmentsForDecreaseIncreaseInAccountsReceivableFromStateOfMinasGerais
229 CVA and Other financial components in tariff adjustments Concept (Monetary) For Period Debit xcmig:AdjustmentsForDecreaseIncreaseInCvaAndOtherFinancialComponentsInTariffAdjustments
230 Energy Development Account (CDE) Concept (Monetary) For Period Debit xcmig:AdjustmentsForDecreaseIncreaseInEnergyDevelopmentAccount
231 Recoverable taxes Concept (Monetary) For Period Debit ifrs-full:IncomeTaxesRefundClassifiedAsOperatingActivities
232 Income and social contribution tax credit Concept (Monetary) For Period Debit xcmig:AdjustmentsForDecreaseIncreaseInIncomeAndSocialContributionTaxCredit
233 Escrow deposits Concept (Monetary) For Period Debit xcmig:AdjustmentsForDecreaseIncreaseInEscrowDeposits
234 Dividends received from investments Concept (Monetary) For Period Debit ifrs-full:DividendsReceivedClassifiedAsOperatingActivities
235 Concession financial assets Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseInFinancialAssets
236 Advances to suppliers Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDecreaseIncreaseInLoansAndAdvancesToCustomers
237 Gas drawing rights Concept (Monetary) For Period Debit xcmig:AdjustmentForDecreaseIncreaseInGasDrawingRights
238 Others Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDecreaseIncreaseInOtherAssets
239 Total (increase) / decrease in assets Concept (Monetary) For Period Debit xcmig:AdjustmentsForDecreaseIncreaseInAssets
240 Increase (decrease) in liabilities Abstract xcmig:AdjustmentsForIncreaseDecreaseInLiabilitiesAbstract
241 Suppliers Concept (Monetary) For Period Debit xcmig:AdjustmentsForIncreaseDecreaseInSuppliers
242 Taxes payable Concept (Monetary) For Period Debit xcmig:AdjustmentsForIncreaseDecreaseInTaxesPayable
243 Income and social contribution taxes payable Concept (Monetary) For Period Debit xcmig:AdjustmentsForIncreaseDecreaseInIncomeAndSocialContributionTaxesPayable
244 Payroll and related charges Concept (Monetary) For Period Debit xcmig:AdjustmentsForIncreaseDecreaseInPayrollAndRelatedCharges
245 Regulatory charges Concept (Monetary) For Period Debit xcmig:AdjustmentsForIncreaseDecreaseInRegulatoryCharges
246 Advances from clients Concept (Monetary) For Period Debit xcmig:AdjustmentsForIncreaseDecreaseInAdvancesFromClients
247 Post-retirement obligation Concept (Monetary) For Period Debit xcmig:AdjustmentsForIncreaseDecreaseInPostretirementLiabilities
248 Derivative financial instruments - Put options Concept (Monetary) For Period Debit xcmig:AdjustmentsForIncreaseDecreaseInDerivativeFinancialInstrumentsPutOptions
249 Others Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForIncreaseDecreaseInOtherLiabilities
250 Total increase (decrease) in liabilities Concept (Monetary) For Period Credit xcmig:AdjustmentsForIncreaseDecreaseInLiabilities
251 Cash generated by operating activities Concept (Monetary) For Period Debit xcmig:CashGeneratedByOperatingActivitiesContinuingOperations
252 Interest paid on loans and financings Concept (Monetary) For Period Credit ifrs-full:InterestPaidClassifiedAsOperatingActivities
253 Income and Social Contribution taxes paid Concept (Monetary) For Period Credit ifrs-full:IncomeTaxesPaidRefundClassifiedAsOperatingActivities
254 NET CASH FROM OPERATING ACTIVITIES Concept (Monetary) For Period ifrs-full:CashFlowsFromUsedInOperatingActivities
255 INVESTING ACTIVITIES Abstract ifrs-full:CashFlowsFromUsedInInvestingActivitiesAbstract
256 Marketable securities Concept (Monetary) For Period Credit xcmig:RedemptionsPaymentsForProceedsFromMarketableSecurities
257 Financial assets Concept (Monetary) For Period Credit ifrs-full:PurchaseOfAvailableforsaleFinancialAssets
258 Restricted cash Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromUsedInDecreaseIncreaseInRestrictedCashAndCashEquivalents
259 Investments Concept (Monetary) For Period Credit ifrs-full:PurchaseOfInterestsInInvestmentsAccountedForUsingEquityMethod
260 Acquisition of equity investees Concept (Monetary) For Period Credit xcmig:PaymentsForAcquisitionOfEquityInvestees
261 Disposal of investments Concept (Monetary) For Period Debit ifrs-full:ProceedsFromSalesOfInvestmentProperty
262 Capital contributions in investees Concept (Monetary) For Period Credit xcmig:PaymentsForCapitalContributionsInInvestees
263 Property, plant and equipment Concept (Monetary) For Period Credit ifrs-full:PurchaseOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities
264 Intangible assets Concept (Monetary) For Period Credit ifrs-full:PurchaseOfIntangibleAssetsClassifiedAsInvestingActivities
265 NET CASH USED IN INVESTING ACTIVITIES Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromUsedInInvestingActivities
266 FINANCING ACTIVITIES Abstract ifrs-full:CashFlowsFromUsedInFinancingActivitiesAbstract
267 Subscription of shares, to be capitalized Concept (Monetary) For Period Debit xcmig:ProceedsFromSubscriptionOfSharesToBeCapitalized
268 Proceeds from Loans, financings and debentures Concept (Monetary) For Period Debit ifrs-full:ProceedsFromIssueOfBondsNotesAndDebentures
269 Borrowing costs Concept (Monetary) For Period Debit ifrs-full:ProceedsFromBorrowingsClassifiedAsFinancingActivities
270 Payment of loans, financings and debentures Concept (Monetary) For Period Credit ifrs-full:RepaymentsOfBondsNotesAndDebentures
271 Interest on capital and dividends paid Concept (Monetary) For Period Credit ifrs-full:PaymentsFromChangesInOwnershipInterestsInSubsidiaries
272 NET CASH (USED IN) FROM FINANCING ACTIVITIES Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromUsedInFinancingActivities
273 Net increase in cash and cash equivalents Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseInCashAndCashEquivalents
274 Cash and cash equivalents at the beginning of the year Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalentsIfDifferentFromStatementOfFinancialPosition
275 Cash and cash equivalents at the end of the year Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalentsIfDifferentFromStatementOfFinancialPosition
276 1009 - Disclosure - Operating Context Network

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277 Implied Table Table

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278 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
279 Operating Context Concept (Text Block (HTML)) For Period xcmig:DisclosureOfOperatingContextExplanatory
280 1010 - Disclosure - Basis of Preparation Network

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281 Implied Table Table

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282 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
283 Basis of Preparation Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfBasisOfPreparationOfFinancialStatementsExplanatory
284 1011 - Disclosure - Principles of Consolidation Network

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285 Implied Table Table

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286 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
287 Principles of Consolidation Concept (Text Block (HTML)) For Period xcmig:DisclosureOfPrinciplesOfConsolidationExplanatory
288 1012 - Disclosure - Concessions and Authorizations Network

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289 Implied Table Table

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290 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
291 Concessions and Authorizations Concept (Text Block (HTML)) For Period xcmig:DisclosureOfElectricityConcessionsAndAuthorizationsExplanatory
292 1013 - Disclosure - Operating Segments Network

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293 Implied Table Table

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294 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
295 Operating Segments Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfEntitysReportableSegmentsExplanatory
296 1014 - Disclosure - Cash and Cash Equivalents Network

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297 Implied Table Table

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298 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
299 Cash and Cash Equivalents Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfCashAndCashEquivalentsExplanatory
300 1015 - Disclosure - Securities Network

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301 Implied Table Table

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302 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
303 Securities Concept (Text Block (HTML)) For Period xcmig:DisclosureOfInvestmentSecuritiesExplanatory
304 1016 - Disclosure - Customers, Traders and Power Transport Concession Holders Network

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305 Implied Table Table

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306 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
307 Customers, Traders and Power Transport Concession Holders Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfTradeAndOtherReceivablesExplanatory
308 1017 - Disclosure - Recoverable Taxes Network

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309 Implied Table Table

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310 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
311 Recoverable Taxes Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDetailedInformationAboutRecoverableTaxesExplanatory
312 1018 - Disclosure - Income and Social Contribution Taxes Network

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313 Implied Table Table

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314 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
315 Income and Social Contribution Taxes Concept (Text Block (HTML)) For Period xcmig:DisclosureOfIncomeAndSocialContributionTaxesExplanatory
316 1019 - Disclosure - Restricted Cash Network

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317 Implied Table Table

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318 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
319 Restricted Cash Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfRestrictedCashAndCashEquivalentsExplanatory
320 1020 - Disclosure - Accounts Receivable from The State of Minas Gerais Network

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321 Implied Table Table

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322 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
323 Accounts Receivable from The State of Minas Gerais Concept (Text Block (HTML)) For Period xcmig:DisclosureOfAccountsReceivableExplanatory
324 1021 - Disclosure - Escrow Deposits Network

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325 Implied Table Table

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326 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
327 Escrow Deposits Concept (Text Block (HTML)) For Period xcmig:DisclosureOfEscrowDepositsExplanatory
328 1022 - Disclosure - Reimbursement Of Tariff Subsidies Network

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329 Implied Table Table

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330 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
331 Reimbursement Of Tariff Subsidies Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfReimbursementRightsExplanatory
332 1023 - Disclosure - Concession Financial Assets and Liabilities Network

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333 Implied Table Table

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334 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
335 Concession Financial Assets and Liabilities Concept (Text Block (HTML)) For Period xcmig:DisclosureOfFinancialAssetsAndLiabilitiesByCategoriesExplanatory
336 1024 - Disclosure - Investments Network

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337 Implied Table Table

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338 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
339 Investments Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfInvestmentPropertyExplanatory
340 1025 - Disclosure - Property, Plant and Equipment Network

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341 Implied Table Table

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342 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
343 Property, Plant and Equipment Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfPropertyPlantAndEquipmentExplanatory
344 1026 - Disclosure - Intangible Assets Network

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345 Implied Table Table

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346 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
347 Intangible Assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfIntangibleAssetsWithIndefiniteUsefulLifeExplanatory
348 1027 - Disclosure - Suppliers Network

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349 Implied Table Table

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350 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
351 Suppliers Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForTradeAndOtherPayablesExplanatory
352 1028 - Disclosure - Taxes, Income Tax and Social Contribution Network

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353 Implied Table Table

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354 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
355 Taxes, Income Tax and Social Contribution Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfIncomeTaxExplanatory
356 1029 - Disclosure - Loans, Financings and Debentures Network

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357 Implied Table Table

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358 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
359 Loans, Financings and Debentures Concept (Text Block (HTML)) For Period xcmig:DisclosureLoansFinancingsAndDebenturesExplanatory
360 1030 - Disclosure - Regulatory Charges Network

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361 Implied Table Table

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362 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
363 Regulatory Charges Concept (Text Block (HTML)) For Period xcmig:DisclosureOfRegulatoryChargeExplanatory
364 1031 - Disclosure - Post-Retirement Obligation Network

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365 Implied Table Table

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366 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
367 Post-Retirement Obligation Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDefinedBenefitPlansExplanatory
368 1032 - Disclosure - Provisions Network

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369 Implied Table Table

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370 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
371 Provisions Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDetailedInformationAboutProvisionsForContingenciesExplanatory
372 1033 - Disclosure - Equity and Remuneration to Shareholders Network

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373 Implied Table Table

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374 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
375 Equity and Remuneration to Shareholders Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfShareCapitalReservesAndOtherEquityInterestExplanatory
376 1034 - Disclosure - Revenue Network

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377 Implied Table Table

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378 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
379 Revenue Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfRevenueExplanatory
380 1035 - Disclosure - Operating Costs and Expenses Network

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381 Implied Table Table

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382 Analysis of income and expense [abstract] Abstract ifrs-full:AnalysisOfIncomeAndExpenseAbstract
383 Operating Costs and Expenses Concept (Text Block (HTML)) For Period xcmig:DisclosureOfOperatingCostsAndExpensesExplanatory
384 1036 - Disclosure - Finance Income and Expenses Network

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385 Implied Table Table

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386 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
387 Finance Income and Expenses Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfFinanceIncomeExpenseExplanatory
388 1037 - Disclosure - Related Party Transactions Network

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389 Implied Table Table

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390 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
391 Related Party Transactions Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfRelatedPartyExplanatory
392 1038 - Disclosure - Financial Instruments and Risk Management Network

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393 Implied Table Table

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394 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
395 Financial Instruments and Risk Management Concept (Text Block (HTML)) For Period xcmig:DisclosureOfFinancialInstrumentsAndFinancialRiskManagementExplanatory
396 1039 - Disclosure - Measurement at Fair Value Network

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397 Implied Table Table

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398 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
399 Measurement at Fair Value Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfFairValueMeasurementExplanatory
400 1040 - Disclosure - Insurance Network

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401 Implied Table Table

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402 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
403 Insurance Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfInsuranceContractsExplanatory
404 1041 - Disclosure - Commitments Network

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405 Implied Table Table

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406 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
407 Commitments Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfCommitmentsExplanatory
408 1042 - Disclosure - The Annual Tariff Adjustment Network

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409 Implied Table Table

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410 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
411 The Annual Tariff Adjustment Concept (Text Block (HTML)) For Period xcmig:DisclosureOfAnnalTariffAdjustmentsExplanatory
412 1043 - Disclosure - Non-Cash Transactions Network

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413 Implied Table Table

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414 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
415 Non-Cash Transactions Concept (Text Block (HTML)) For Period xcmig:DisclosureOfSignificantNoncashActivitiesExplanatory
416 1044 - Disclosure - Subsequent Events Network

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417 Implied Table Table

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418 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
419 Subsequent Events Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfEventsAfterReportingPeriodExplanatory
420 1045 - Disclosure - Basis of Preparation (Policies) Network

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421 Implied Table Table

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422 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
423 Financial instruments Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForFinancialInstrumentsExplanatory
424 Customers and traders; Concession holders (power transport) Concept (Text Block (HTML)) For Period xcmig:DescriptionOfAccountingPolicyForCustomersAndTradersConcessionHoldersPowerTransportExplanatory
425 Investments Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForInvestmentsOtherThanInvestmentsAccountedForUsingEquityMethodExplanatory
426 Concession assets Concept (Text Block (HTML)) For Period xcmig:DescriptionOfAccountingPolicyForConcessionAssetsExplanatory
427 Intangible assets Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForIntangibleAssetsOtherThanGoodwillExplanatory
428 Property, plant and equipment Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForPropertyPlantAndEquipmentExplanatory
429 Impairment Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForImpairmentOfAssetsExplanatory
430 Benefits to employees Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForEmployeeBenefitsExplanatory
431 Income tax and Social Contribution tax Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForDeferredIncomeTaxExplanatory
432 Operational revenue Concept (Text Block (HTML)) For Period xcmig:DescriptionOfAccountingPolicyForOperationalRevenueExplanatory
433 Financial revenue and expenses Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForFinanceIncomeAndCostsExplanatory
434 Segment reporting Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForSegmentReportingExplanatory
435 1046 - Disclosure - Basis of Preparation (Tables) Network

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436 Implied Table Table

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437 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
438 Estimated Effects Arising from Adoption of the Pronouncement Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfExpectedImpactOfInitialApplicationOfNewStandardsOrInterpretations
439 1047 - Disclosure - Principles of Consolidation (Tables) Network

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440 Implied Table Table

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441 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
442 Schedule of Companies Direct Equity Investments Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfBasisOfConsolidationExplanatory
443 1048 - Disclosure - Concessions and Authorizations (Tables) Network

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444 Implied Table Table

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445 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
446 Schedule of Concessions and Authorizations Held Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDetailedInformationAboutElectricityConcessionsAndAuthorizationsExplanatory
447 Schedule of Concession and Amount to Be Paid Concept (Text Block (HTML)) For Period xcmig:DisclosureOfConcessionAndAmountToBePaidExplanatory
448 Schedule of Present Value and Nominal Value Portion to Be paid Concept (Text Block (HTML)) For Period xcmig:DisclosureOfPresentValueAndNominalValuePortionToBePaidExplanatory
449 1049 - Disclosure - Operating Segments (Tables) Network

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450 Implied Table Table

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451 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
452 Schedule of Operating Revenues, Costs and Expenses Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfOperatingSegmentsExplanatory
453 1050 - Disclosure - Cash and Cash Equivalents (Tables) Network

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454 Implied Table Table

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455 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
456 Summary of Cash and Cash Equivalents Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDetailedCashAndCashEquivalentsExplanatory
457 1051 - Disclosure - Securities (Tables) Network

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458 Implied Table Table

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459 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
460 Securities Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDetailedInformationAboutInvestmentSecuritiesExplanatory
461 1052 - Disclosure - Customers, Traders and Power Transport Concession Holders (Tables) Network

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462 Implied Table Table

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463 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
464 Summary of Trade and Other Receivables Concept (Text Block (HTML)) For Period xcmig:DisclosureDetailedInformationOfTradeAndOtherReceivablesExplanatory
465 Summary of Provision for Allowance for Doubtful Accounts Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfProvisionsExplanatory
466 Summary of Changes in Provision for Doubtful Accounts Concept (Text Block (HTML)) For Period xcmig:DisclosureOfChangesInProvisionForDoubtfulReceivablesExplanatory
467 Summary of Advances from Customers Concept (Text Block (HTML)) For Period xcmig:DisclosureOfAdvancesFromCustomersExplanatory
468 Summary of Terms of Advances from Clients Concept (Text Block (HTML)) For Period xcmig:DisclosureOfTermsOfAdvancesFromCustomersExplanatory
469 1053 - Disclosure - Recoverable Taxes (Tables) Network

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470 Implied Table Table

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471 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
472 Summary of Recoverable Taxes Concept (Text Block (HTML)) For Period xcmig:DisclosureOfSourceOfRecoverableTaxesExplanatory
473 1054 - Disclosure - Income and Social Contribution Taxes (Tables) Network

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474 Implied Table Table

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475 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
476 Summary of Income and Social Contribution Taxes recoverable Concept (Text Block (HTML)) For Period xcmig:DisclosureOfIncomeAndSocialContributionTaxesRecoverableExplanatory
477 Summary of Deferred Income and Social Contribution Taxes Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDeferredIncomeAndSocialContributionTaxesExplanatory
478 Summary of Changes in Deferred Income and Social Contribution Taxes Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDeferredTaxesExplanatory
479 Summary of Estimated Balance of Deferred Tax Asset Concept (Text Block (HTML)) For Period xcmig:DisclosureOfEstimatedBalanceOfDeferredTaxAssetExplanatory
480 Summary of Reconciliation of Statutory on Income and Social Contribution Taxes Concept (Text Block (HTML)) For Period xcmig:DisclosureOfReconciliationOfStatutoryOnIncomeAndSocialContributionTaxesExplanatory
481 1055 - Disclosure - Escrow Deposits (Tables) Network

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482 Implied Table Table

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483 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
484 Schedule of Payments Related to Escrow Deposits Concept (Text Block (HTML)) For Period xcmig:DisclosureOfPaymentsForEscrowDepositsExplanatory
485 1056 - Disclosure - Concession Financial Assets and Liabilities (Tables) Network

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486 Statement [Table] Table

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487 Types of investment property [axis] Axis ifrs-full:TypesOfInvestmentPropertyAxis
488 Investment property [member] Member ifrs-full:InvestmentPropertyMember
489 Miranda and Sao Simao hydroelectric plants [member] Member xcmig:MirandaAndSaoSimaoHydroelectricPlantsMember
490 Statement [Line Items] LineItems us-gaap:StatementLineItems
491 Summary of Financial Assets and Liabilities of Concession Concept (Text Block (HTML)) For Period xcmig:DisclosureOfFinancialAssetsAndLiabilitiesOfTheConcessionExplanatory
492 Summary of Changes in Concession Financial Assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfFinancialAssetsExplanatory
493 Summary of Indemnity Values Concept (Text Block (HTML)) For Period xcmig:DisclosureOfIndemnityExplonatory
494 Summary of Generation Indemnity Receivable Concept (Text Block (HTML)) For Period xcmig:DisclosureOfGenerationIndemnityReceivableIncludingDeemedCostExplanatoryTextBlock
495 Summary of Auction Won Transferred to Related Specific Purpose Companies Concept (Text Block (HTML)) For Period xcmig:DisclosureOfAuctionWonTransferredToRelatedSpecificPurposeCompaniesExplanatory
496 Summary of Financial Assets and Financial Liabilities With the Tariff Adjustments Concept (Text Block (HTML)) For Period xcmig:DisclosureOfFinancialAssetsAndFinancialLiabilitiesWithTheTariffAdjustmentsExplanatory
497 Summary of Changes in Balances of Financial Assets and Liabilities Concept (Text Block (HTML)) For Period xcmig:DisclosureOfChangesInBalancesOfFinancialAssetsAndLiabilitiesTextBlock
498 1057 - Disclosure - Investments (Tables) Network

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499 Implied Table Table

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500 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
501 Percentage of the Company's Equity Interest Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfInvestmentsAccountedForUsingEquityMethodExplanatory
502 Allocation of Acquisition Price of Jointly-Controlled Subsidiaries, A Valuation was Made of Intangible Assets Relating to Right to Operate Regulated Activity Concept (Text Block (HTML)) For Period xcmig:DisclosureInInvestmentsInAssociatesAndJointVenturesExplanatory
503 Movement of Investments in the Jointly-Controlled Entities Concept (Text Block (HTML)) For Period xcmig:DisclosureOfMovementsInAssociatesJointVenturesAndOtherInvestmentsExplanatory
504 Principal Information on the Subsidiaries and Jointly-Controlled Entities Concept (Text Block (HTML)) For Period xcmig:DisclosureOfInvestmentsInSubsidiariesJointVenturesAndAssociatesExplanatory
505 Summarized Financial Information of the Company's Equity Investees Concept (Text Block (HTML)) For Period xcmig:DisclosureOfFinancialInformationOfEquityInvesteesExplanatory
506 Disclosure Of Fair Value Of The Assets Acquired Resulted In Fair Value Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutBusinessCombinationsExplanatory
507 1058 - Disclosure - Property, Plant and Equipment (Tables) Network

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508 Implied Table Table

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509 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
510 Schedule of Property, Plant and Equipment Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutPropertyPlantAndEquipmentExplanatory
511 Movement in Property, Plant and Equipment Concept (Text Block (HTML)) For Period xcmig:DisclosureOfMovementInPropertyPlantAndEquipmentExplanatory
512 Summary of Accumulated Investments in Consortium Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutInvestmentPropertyExplanatory
513 1059 - Disclosure - Intangible Assets (Tables) Network

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514 Implied Table Table

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515 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
516 Summary of Composition of Intangible Assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutIntangibleAssetsExplanatory
517 Summary of Changes in Intangible Assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfReconciliationOfChangesInIntangibleAssetsAndGoodwillExplanatory
518 1060 - Disclosure - Suppliers (Tables) Network

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519 Implied Table Table

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520 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
521 Summary of Suppliers Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfTradeAndOtherPayablesExplanatory
522 1061 - Disclosure - Taxes, Income Tax and Social Contribution (Tables) Network

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523 Implied Table Table

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524 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
525 Summary of Tax Payable Concept (Text Block (HTML)) For Period xcmig:DisclosureOfTaxesPayableExplanatory
526 Summary of Income Tax and Social Contribution Tax Concept (Text Block (HTML)) For Period xcmig:DisclosureOfIncomeTaxAndSocialContributionTaxExplanatory
527 1062 - Disclosure - Loans, Financings and Debentures (Tables) Network

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528 Implied Table Table

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529 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
530 Summary of Loans Financing and Debentures Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsExplanatory
531 Summary of Guarantees of the Debtor Balance on Loans and Financings Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDetailedInformationAboutGuaranteesExplanatory
532 Summary Consolidated Composition of Loans, Financings and Debentures, by Currency and Indexor, with the Respective Amortization Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDetailedInformationAboutLoansFinancingsAndDebenturesByCurrencyAndIndexOrExplanatory
533 Summary of the Principal Currencies and Indexors Used for Monetary Updating of Loans and Financings Concept (Text Block (HTML)) For Period xcmig:DisclosureOfPrincipalCurrenciesAndIndexorsUsedForMonetaryUpdatingOfLoansAndFinancingsExplanatory
534 Summary of changes in loans, financings and debentures Concept (Text Block (HTML)) For Period xcmig:DisclosureOfChangesInLoansFinancingsAndDebenturesExplanatory
535 Transferred to Intangible Assets the Costs of Loans and Financings Linked to Working in Progress Concept (Text Block (HTML)) For Period xcmig:DisclosureOfCapitalizedBorrowingCostsExplanatory
536 Consolidated Totals of Funds Raised Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDetailedInformationAboutFundsRaisedExplanatory
537 Characteristics of NonConvertible Debentures Issued by Company Concept (Text Block (HTML)) For Period xcmig:DisclosureOfCharacteristicsOfNonConvertibleDebenturesIssuedExplanatory
538 Summary of Contracts with Covenants Linked to Financial Index Concept (Text Block (HTML)) For Period xcmig:DisclosureOfContractsWithCovenantsLinkedToFinancialIndicesTextBlock
539 1063 - Disclosure - Regulatory Charges (Tables) Network

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540 Implied Table Table

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541 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
542 Disclosure of Information About Amounts Recognised in Relation to Regulatory Deferral Account Balances Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDetailedInformationAboutRegulatoryChargesExplanatory
543 1064 - Disclosure - Post-Retirement Obligation (Tables) Network

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544 Implied Table Table

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545 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
546 Disclosure Of Consolidated Actuarial Information Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDefinedBenefitPlansActuarialInformationExplanatory
547 Disclosure of Changes In Present Value of Defined Benefit Obligation Concept (Text Block (HTML)) For Period xcmig:DisclosureOfChangesInPresentValueOfDefinedBenefitObligationsExplanatory
548 Disclosure of Changes in the Fair Value of Plan Assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfFairValueOfPlanAssetsExplanatory
549 Disclosure of Defined Benefit Plans Expense Recognised in Income Statement Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDefinedBenefitPlansExpenseRecognisedInIncomeStatementExplanatory
550 Summary of Changes in Net Liabilities Concept (Text Block (HTML)) For Period xcmig:DisclosureOfChangesInNetLiabilitiesExplanatory
551 Summary of Independent Actuaries Estimate for the Expense Amount Concept (Text Block (HTML)) For Period xcmig:DisclosureOfIndependentActuariesEstimateForTheExpenseAmountExplanatory
552 Summary of Expectation for Payment of Benefits Concept (Text Block (HTML)) For Period xcmig:DisclosureOfEstimateOfPaymentsOfBenefitsExplanatory
553 Summary of Average Periods of the Obligations Under the Benefit Plans Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfInformationAboutMaturityProfileOfDefinedBenefitObligationExplanatory
554 Summary of Principal Categories Percentage of Plan Assets Concept (Text Block (HTML)) For Period xcmig:DisclosureOfPercentageOfPlanAssetsExplanatory
555 Summary of Fair Value of Pension Plan Assets Issued by Sponsors and Subsidiaries Concept (Text Block (HTML)) For Period xcmig:DisclosureOfFairValueOfPlanAssetsIssuedBySponsorsAndSubsidiariesExplanatory
556 Summary of Actuarial Assumptions Concept (Text Block (HTML)) For Period xcmig:DisclosureOfActuarialAssumptionsExplanatory
557 Summary of Sensitivity Analysis of the Effects of Changes in the Principal Actuarial Assumptions Used to Determine the Defined-benefit Obligation Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfSensitivityAnalysisForActuarialAssumptionsExplanatory
558 1065 - Disclosure - Provisions (Tables) Network

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559 Implied Table Table

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560 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
561 Schedule of Provisions for Contingencies Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfOtherProvisionsExplanatory
562 1066 - Disclosure - Equity and Remuneration to Shareholders (Tables) Network

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563 Implied Table Table

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564 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
565 Summary of Share Capital for Common Shares and Preferred Shares Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfClassesOfShareCapitalExplanatory
566 Summary of Shares used in Calculation of Basic Profit and Diluted Earnings per Share Concept (Text Block (HTML)) For Period ifrs-full:EarningsPerShareExplanatory
567 Summary of Calculation of Basic Earnings per Share Concept (Text Block (HTML)) For Period xcmig:DisclosureOfBasicEarningsPerShareExplanatory
568 Summary of Calculation of Diluted Earnings per Share Concept (Text Block (HTML)) For Period xcmig:DisclosureOfCalculationOfDilutedProfitExplanatory
569 Schedule of Capital Reserves and Profit Reserves Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfReservesAndOtherEquityInterestExplanatory
570 Summary of Reserve for Obligatory Dividends Not Distributed Concept (Text Block (HTML)) For Period xcmig:DisclosureOfReserveForObligatoryDividendsExplanatory
571 Schedule of Dividends Proposed for Distribution to Shareholders Based on the Profit for the Business Year Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDividendsExplanatory
572 Summary of Equity Valuation Adjustments Concept (Text Block (HTML)) For Period xcmig:DisclosureOfValuationAndQualifyingAccountsExplanatory
573 1067 - Disclosure - Revenue (Tables) Network

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574 Implied Table Table

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575 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
576 Summary of Net Operating Revenue Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDetailedInformationAboutRevenueExplanatory
577 Summary of the Supply of Electricity by Type of Consumer Concept (Text Block (HTML)) For Period xcmig:DisclosureOfSupplyOfElectricityByTypeOfConsumerExplanatory
578 Summary of Other Operating Revenues Concept (Text Block (HTML)) For Period xcmig:DisclosureOfOtherOperatingRevenueExplanatory
579 Summary of Deductions from Revenue Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDeductionsOnRevenueExplanatory
580 1068 - Disclosure - Operating Costs and Expenses (Tables) Network

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581 Implied Table Table

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582 Analysis of income and expense [abstract] Abstract ifrs-full:AnalysisOfIncomeAndExpenseAbstract
583 Summary of Operating Costs and Expenses Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDetailedInformationAboutOperatingCostsAndExpensesExplanatory
584 Summary of Outsourced Services Concept (Text Block (HTML)) For Period xcmig:DisclosureOfOutsourcedServicesExplanatory
585 Summary of Electricity Purchased for Resale Concept (Text Block (HTML)) For Period xcmig:DisclosureOfElectricityPurchasedForResaleInOperatingCostsAndExpensesExplanatory
586 Summary of Operating Provisions (Reversals) Concept (Text Block (HTML)) For Period xcmig:DisclosureOfOperatingProvisionsReversalsExplanatory
587 Summary of Construction Cost Concept (Text Block (HTML)) For Period xcmig:DisclosureOfConstructionCostExplanatory
588 Summary of Other Operating Expenses (Revenues), Net Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfOtherOperatingIncomeExpenseExplanatory
589 1069 - Disclosure - Finance Income and Expenses (Tables) Network

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590 Implied Table Table

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591 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
592 Summary of Financial Income and Expenses Concept (Text Block (HTML)) For Period xcmig:DisclosureOfDetailInformationAboutFinancialIncomeAndExpensesExplanatory
593 1070 - Disclosure - Related Party Transactions (Tables) Network

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594 Statement [Table] Table

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595 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
596 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
597 Related parties [member] Member ifrs-full:RelatedPartiesMember
598 Statement [Line Items] LineItems us-gaap:StatementLineItems
599 Summary of Cemig's Principal Balances and Transactions With Related Parties Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesExplanatory
600 Summary of Cemig is Provider of Surety or Guarantee of Loans, Financings and Debentures of Related Parties Concept (Text Block (HTML)) For Period xcmig:DisclosureOfGuaranteesOfLoansFinancingAndDebenturesExplanatory
601 Summary of Financial Investments in Securities of Related Parties, in the Investment Fund Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfInterestsInSubsidiariesExplanatory
602 Summary of Total Costs of Key Management Personnel Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfInformationAboutKeyManagementPersonnelExplanatory
603 1071 - Disclosure - Financial Instruments and Risk Management (Tables) Network

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604 Implied Table Table

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605 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
606 Summary of Net Liabilities in Relation to its Equity Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfFinancialLiabilitiesExplanatory
607 1072 - Disclosure - Measurement at Fair Value (Tables) Network

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608 Implied Table Table

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609 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
610 Summary of Instruments Measured at Fair Value Concept (Text Block (HTML)) For Period xcmig:DisclosureOfFinancialAssetsAndLiabilitiesMeasuredAtFairValueExplanatory
611 1073 - Disclosure - Insurance (Tables) Network

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612 Implied Table Table

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613 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
614 Summary ofAmounts Arising From Insurance Contracts Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfAmountsArisingFromInsuranceContractsExplanatory
615 1074 - Disclosure - Commitments (Tables) Network

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616 Implied Table Table

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617 Text block1 [abstract] Abstract xcmig:TextBlock1Abstract
618 Detailed Information about Contractual Obligations and Commitments Concept (Text Block (HTML)) For Period xcmig:DisclosureOfSourceOfCommitmentsExplanatory
619 1075 - Disclosure - Operating Context - Additional Information (Detail) Network

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620 Disclosure of operating context [Table] Table

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621 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
622 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
623 Cemig GT [member] Member xcmig:CemigGTMember
624 Cemig Gerao Trs Marias S.A. [member] Member xcmig:CemigGeraoTrsMariasSAMember
625 Cemig Gerao Salto Grande S.A. [member] Member xcmig:CemigGeraoSaltoGrandeSAMember
626 Cemig Gerao Camargos S.A. [member] Member xcmig:CemigGeraoCamargosSAMember
627 Cemig Geracao Itutinga S.A. [member] Member xcmig:CemigGeracaoItutingaMember
628 Cemig Geracao Lest S.A. [member] Member xcmig:CemigGeracaoLestMember
629 Cemig Geracao Oeste S.A. [member] Member xcmig:CemigGeracaoOesteSAMember
630 Cemig Geracao Sul S.A. [member] Member xcmig:CemigGeracaoSulSAMember
631 Cemig Telecomunicacoes S.A. [member] Member xcmig:CemigTelecomunicacoesSAMember
632 Ceming GT [Member] Member xcmig:CemingGTMember
633 Classes of property, plant and equipment [axis] Axis ifrs-full:ClassesOfPropertyPlantAndEquipmentAxis
634 Property, plant and equipment [member] Member ifrs-full:PropertyPlantAndEquipmentMember
635 Hydroelectrical power plants [member] Member xcmig:HydroelectricalPowerPlantsMember
636 Wind power plants [member] Member xcmig:WindPowerPlantsMember
637 Thermal power plant [member] Member xcmig:ThermalPowerPlantMember
638 Joint operations [axis] Axis ifrs-full:JointOperationsAxis
639 Entity's total for joint operations [member] Member ifrs-full:EntitysTotalForJointOperationsMember
640 Baguari Energia [member] Member xcmig:BaguariEnergiaMember
641 Neoenergia [member] Member xcmig:NeoenergiaMember
642 Alianca Norte [member] Member xcmig:AliancaNorteMember
643 Amazonia energia participacoes S A [member] Member xcmig:AmazoniaEnergiaParticipacoesSAMember
644 Alianca [member] Member xcmig:AliancaMember
645 Transmissora Alianca de Energia Eletrica S.A. [member] Member xcmig:TransmissoraAliancadeEnergiaEletricaSAMember
646 Axxiom solucoesTecnologicas S.A. [member] Member xcmig:AxxiomSolucoesTecnologicasSAMember
647 Ativas Data Center [member] Member xcmig:AtivasDataCenterMember
648 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
649 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
650 Vale [member] Member xcmig:ValeMember
651 Norte Energia [member] Member xcmig:NorteEnergiaMember
652 Light SA [member] Member xcmig:LightSAMember
653 Norte Energia S.A [Member] Member xcmig:NorteEnergiaSAMember
654 Light [member] Member xcmig:LightMember
655 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
656 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
657 Brazil [member] Member xcmig:BrazilMember
658 Disclosure of operating context [line items] LineItems xcmig:DisclosureOfOperatingContextLineItems
659 Current liabilities exceeded current assets amount Concept (Monetary) As Of Debit ifrs-full:CurrentAssetsLiabilities
660 Short-term loans, financings and debentures Concept (Monetary) As Of Credit ifrs-full:ShorttermBorrowings
661 Long-term loans, financings and debentures Concept (Monetary) As Of Credit ifrs-full:LongtermBorrowings
662 Positive operating cash flows Concept (Monetary) For Period ifrs-full:CashFlowsFromUsedInOperatingActivities
663 Indebtedness from loans, financings and debentures Concept (Monetary) As Of Credit ifrs-full:Borrowings
664 Debt Concept (Monetary) For Period Debit xcmig:EuroBondsIssued
665 Reprofiling of debt Concept (Monetary) For Period Debit xcmig:ReprofilingOfDebt
666 Number of power plants Concept (Integer) For Period xcmig:NumberOfPowerPlants
667 Ownership interest Concept (Percent) For Period ifrs-full:ProportionOfOwnershipInterestInJointOperation
668 Interest acquisition percentage Concept (Percent) As Of ifrs-full:PercentageOfVotingEquityInterestsAcquired
669 Plant capacity Concept (num:powerItemType) For Period xcmig:PowerPlantCapacity
670 Assured energy offtake level of plant Concept (num:powerItemType) For Period xcmig:AssuredEnergyOfftakeLevelOfPlant
671 Percentage of total capital holding Concept (Percent) For Period xcmig:PercentageOfEquityHolding
672 Principal place of business of joint operation Concept (Text/String) For Period ifrs-full:PrincipalPlaceOfBusinessOfJointOperation
673 1076 - Disclosure - Basis of Preparation - Estimated Effects Arising from Adoption of the Pronouncement (Detail) Network

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674 Implied Table Table

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675 Disclosure of expected impact of initial application of new standards or interpretations [abstract] Abstract ifrs-full:DescriptionOfExpectedImpactOfInitialApplicationOfNewStandardsOrInterpretationsAbstract
676 Consumers and Traders; Transport of energy Concept (Monetary) For Period Debit xcmig:AdditionalLossEstimatedFromAdoptionOfPronouncement
677 Consumers and Traders; Transport of energy Concept (Monetary) For Period Debit xcmig:AdditionalLossEstimatedFromAdoptionOfPronouncement
678 1077 - Disclosure - Basis of Preparation - Additional Information (Detail) Network

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679 Disclosure of summary of significant accounting policies [table] Table

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680 Types of customers [axis] Axis ifrs-full:TypesOfCustomersAxis
681 Types of customers [member] Member ifrs-full:TypesOfCustomersMember
682 Residential consumers [member] Member xcmig:ResidentialConsumersMember
683 Commercial consumers [member] Member xcmig:CommercialConsumersMember
684 Other consumers [member] Member xcmig:OtherConsumersMember
685 Retrospective application and retrospective restatement [axis] Axis ifrs-full:RetrospectiveApplicationAndRetrospectiveRestatementAxis
686 Currently stated [member] Member ifrs-full:RestatedMember
687 Increase (decrease) due to application of IFRS 15 [member] Member ifrs-full:IncreaseDecreaseDueToApplicationOfIFRS15Member
688 Disclosure Of Summary Of Significant Accounting Policies [Line Items] LineItems xcmig:DisclosureOfSummaryOfSignificantAccountingPoliciesLineItems
689 Revenue reclassified amount from adoption of pronouncement Concept (Monetary) As Of Credit xcmig:NoncurrentPortionOfDeferredRevenueReclassified
690 Provision for doubtful receivables Concept (xbrli:durationItemType) For Period xcmig:ProvisionsForDoubtfulReceivablesPastDuePeriod
691 Extension of concession agreement period Concept (xbrli:durationItemType) For Period xcmig:AdditionalPeriodOfConcessionAgreement
692 1078 - Disclosure - Principles of Consolidation - Schedule of Companies Direct Equity Investments (Detail) Network

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693 Disclosure of subsidiaries [table] Table

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694 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
695 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
696 Cemig Geracao e Transmissao [member] Member xcmig:CemigGeracaoETransmissaoMember
697 Cemig Distribuicao [member] Member xcmig:CemigDistribuicaoSAMember
698 Gasmig [member] Member xcmig:GasmigMember
699 Cemig Telecom [member] Member xcmig:CemigTelecomMember
700 Rosal Energia [member] Member xcmig:RosalEnergiaMember
701 Sa Carvalho S A [member] Member xcmig:SaCarvalhoSAMember
702 Horizontes Energia [member] Member xcmig:HorizontesEnergiaMember
703 Usina Termica Ipatinga [member] Member xcmig:UsinaTermicaIpatingaSAMember
704 Cemig PCH [member] Member xcmig:CemigpchMember
705 Cemig Trading [member] Member xcmig:CemigtradingMember
706 Efficientia [member] Member xcmig:EfficientiaMember
707 Cemig Comercializadora de Energia Incentivada [member] Member xcmig:CemigcomercializadoradeenergiaincentivadaMember
708 UTE Barreiro (Barreiro Thermal Plant) [member] Member xcmig:UtebarreirobarreirothermalplantMember
709 Empresade Serviose Comercializaode Energia Eltrica [member] Member xcmig:EmpresadeserviosecomercializaodeenergiaeltricaMember
710 Disclosure of subsidiaries [line items] LineItems ifrs-full:DisclosureOfSignificantInvestmentsInSubsidiariesLineItems
711 Direct interest Concept (Percent) For Period ifrs-full:ProportionOfOwnershipInterestInSubsidiary
712 1079 - Disclosure - Concessions and Authorizations - Schedule of Concessions and Authorizations Held (Detail) Network

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713 Disclosure of electricity concessions and authorizations [table] Table

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714 Counterparties [axis] Axis ifrs-full:CounterpartiesAxis
715 Counterparties [member] Member ifrs-full:CounterpartiesMember
716 National electricity aqgency [member] Member xcmig:NationalElectricalEnergyAgencyMember
717 Electricity Distribution [member] Member ifrs-full:ElectricityDistributionMember
718 Classes of property, plant and equipment [axis] Axis ifrs-full:ClassesOfPropertyPlantAndEquipmentAxis
719 Property, plant and equipment [member] Member ifrs-full:PropertyPlantAndEquipmentMember
720 National Grid [member] Member xcmig:NationalGridMember
721 Itajuba Substation [member] Member xcmig:ItajubaSubstationMember
722 Emborcacao hydroelectric plants [member] Member xcmig:EmborcacaoHydroelectricPlantsMember
723 Nova ponte hydroelectric plants [member] Member xcmig:NovaPonteHydroelectricPlantsMember
724 Santa Luzia Hydroelectric Plants [member] Member xcmig:SantaLuziaHydroelectricPlantsMember
725 Sa Carvalho Hydroelectric Plants [member] Member xcmig:SaCarvalhoHydroelectricPlantsMember
726 Rosal Hydroelectric Plants [member] Member xcmig:RosalHydroelectricPlantsMember
727 Machado Mineiro Hydroelectric Plants [member] Member xcmig:MachadoMineiroHydroelectricPlantsMember
728 Salto Voltao Hydroelectric Plants [member] Member xcmig:SaltoVoltaoHydroelectricPlantsMember
729 Salto paraopeba hydroelectric plants [member] Member xcmig:SaltoParaopebaHydroelectricPlantsMember
730 Salto do passo velho hydroelectric plants [member] Member xcmig:SaltoDoPassoVelhoHydroelectricPlantsMember
731 PCH pai joaquim hydro electric plants member [member] Member xcmig:PchPaiJoaquimHydroElectricPlantsMemberMember
732 Irape hydroelectric plants [member] Member xcmig:IrapeHydroelectricPlantsMember
733 Queimado hydroelectric plants [member] Member xcmig:QueimadoHydroelectricPlantsMember
734 Salto morais hydroelectric plants [member] Member xcmig:SaltoMoraisHydroelectricPlantsMember
735 Rio De Pedras Hydroelectric Plants [member] Member xcmig:RioDePedrasHydroelectricPlantsMember
736 Luiz Dias Hydroelectric Plants [member] Member xcmig:LuizDiasHydroelectricPlantsMember
737 Poco Fundo Hydroelectric Plants [member] Member xcmig:PocoFundoHydroelectricPlantsMember
738 Sao Bernardo Hydroelectric Plants [member] Member xcmig:SaoBernardoHydroelectricPlantsMember
739 Xicao Hydroelectric Plants [member] Member xcmig:XicaoHydroelectricPlantsMember
740 Tres Marias Hydroelectric Plants [member] Member xcmig:TresMariasHydroelectricPlantsMember
741 Salto Grande Hydroelectric Plant [member] Member xcmig:SaltoGrandeHydroelectricPlantsMember
742 Itutinga Hydroelectric Plant [member] Member xcmig:ItutingaHydroelectricPlantsMember
743 Camargos Hydroelectric Plant [member] Member xcmig:CamargosHydroelectricPlantsMember
744 Coronel Domiciano Joasal Marmelos Paciencia E Piau Hydroelectric Plants [member] Member xcmig:CoronelDomicianoJoasalMarmelosPacienciaEPiauHydroelectricPlantsMember
745 Dona Rita Ervalia Neblina Peti Sinceridade And Tronqueiras Hydroelectric Plants [member] Member xcmig:DonaRitaErvaliaNeblinaPetiSinceridadeAndTronqueirasHydroelectricPlantsMember
746 Cajuru Gafan Hoto and Martins Hydroelectric Plants [member] Member xcmig:CajuruGafanhotoAndMartinsHydroelectricPlantsMember
747 Igarape thermal plants [member] Member xcmig:IgarapeThermalPlantsMember
748 Disclosure of electricity concessions and authorizations [Line Items] LineItems xcmig:DisclosureOfElectricityConcessionsAndAuthorizationsLineItems
749 Company holding concession or authorization Concept (Text/String) For Period xcmig:ElectricityDistributionConcessionsAndAuthorizationsNameOfCompany
750 Concession or authorization contract Concept (Text/String) For Period xcmig:DateOfElectricityDistributionConcessionsAndAuthorizations
751 Expiration date Concept (Text/String) For Period xcmig:ElectricityDistributionConcessionsAndAuthorizationsExpirationDate
752 Company holding concession or authorization Concept (Text/String) For Period xcmig:ElectricityGenerationConcessionsAndAuthorizationsNameOfCompany
753 Concession or authorization contract Concept (Text/String) For Period xcmig:DateOfElectricityGenerationConcessionsAndAuthorizations
754 Expiration date Concept (Text/String) For Period xcmig:ElectricityGenerationConcessionsAndAuthorizationsExpirationDate
755 Company holding concession or authorization Concept (Text/String) For Period xcmig:ElectricityTransmissionConcessionsAndAuthorizationsNameOfCompany
756 Concession or authorization contract Concept (Text/String) For Period xcmig:DateOfElectricityTransmissionConcessionsAndAuthorizations
757 Expiration date Concept (Text/String) For Period xcmig:ElectricityTransmissionConcessionsAndAuthorizationsExpirationDate
758 Company holding concession or authorization Concept (Text/String) For Period xcmig:GasDistributionConcessionsAndAuthorizationsNameOfCompany
759 Concession or authorization contract Concept (Text/String) For Period xcmig:DateOfGasDistributionConcessionsAndAuthorizations
760 Expiration date Concept (Text/String) For Period xcmig:GasDistributionConcessionsAndAuthorizationsExpirationDate
761 1080 - Disclosure - Concessions and Authorizations - Additional Information (Detail) Network

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762 Disclosure of electricity concessions and authorizations [table] Table

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 xcmig:DisclosureOfElectricityConcessionsAndAuthorizationsTable
763 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
764 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
765 Cemig Distribution [member] Member xcmig:CemigDistributionMember
766 Cemig GT [member] Member xcmig:CemigGTMember
767 Types of contracts [axis] Axis ifrs-full:TypesOfContractsAxis
768 Types of contracts [member] Member ifrs-full:TypesOfContractsMember
769 Second Amendment to Concession Contract [member] Member xcmig:SecondAmendmentToConcessionContractMember
770 Maturity [axis] Axis ifrs-full:MaturityAxis
771 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
772 2019 [member] Member xcmig:TwoThousandAndNineteenMember
773 2020 [member] Member xcmig:TwoThousandTwentyMember
774 Classes of property, plant and equipment [axis] Axis ifrs-full:ClassesOfPropertyPlantAndEquipmentAxis
775 Property, plant and equipment [member] Member ifrs-full:PropertyPlantAndEquipmentMember
776 Sao Simao Jaguara and Miranda hydroelectric plants [member] Member xcmig:SaoSimaoJaguaraAndMirandaHydroelectricPlantsMember
777 Sao simao hydroelectric plant [member] Member xcmig:SaoSimaoHydroelectricPlantMember
778 Miranda hydroelectric plant [member] Member xcmig:MirandaHydroelectricPlantMember
779 Jaguara hydroelectric plant [member] Member xcmig:JaguaraHydroelectricPlantMember
780 Small hydro plants enterprise [member] Member xcmig:SmallHydroPlantsEnterpriseMember
781 Conventional hydroelectric plants enterprise [member] Member xcmig:ConventionalHydroelectricPlantsEnterpriseMember
782 Disclosure of electricity concessions and authorizations [Line Items] LineItems xcmig:DisclosureOfElectricityConcessionsAndAuthorizationsLineItems
783 Plant capacity Concept (num:powerItemType) For Period xcmig:PowerPlantCapacity
784 Sale price of plant Concept (Monetary) For Period Credit xcmig:SaleValueOfPlant
785 Annual generation revenue of plants Concept (Monetary) For Period Credit xcmig:RevenueFromConcessionContracts
786 Residual value of the infrastructure assets Concept (Monetary) As Of Debit xcmig:ResidualValueOfInfrastructureAssets
787 Income from residual value of the infrastructure assets Concept (Monetary) For Period Credit xcmig:IncomeFromResidualValueGuarantee
788 Investment Concept (Monetary) As Of Debit ifrs-full:InvestmentProperty
789 Discount of future payments Concept (Percent) For Period xcmig:DiscountOfLiabilitiesToPresentValue
790 Concession expired Concept (Date) For Period xcmig:ConcessionExpired
791 Percentage of Selic rate Concept (Percent) For Period xcmig:PercentageOfSelicRate
792 Concession contract for electricity generation, additional period Concept (xbrli:durationItemType) For Period xcmig:ConcessionContractForElectricityGenerationPeriod
793 Original expiration date of concession contract Concept (Date) For Period xcmig:OriginalExpirationDateOfConcessionContract
794 Extended expiration date of concession contract Concept (Date) For Period xcmig:ExtendedExpirationDateOfConcessionContract
795 1081 - Disclosure - Concessions and Authorizations - Schedule of Concession and Amount to Be Paid (Detail) Network

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796 Disclosure of concession and amount to be paid [Table] Table

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 xcmig:DisclosureOfConcessionAndAmountToBePaidTable
797 Range [axis] Axis ifrs-full:RangeAxis
798 Ranges [member] Member ifrs-full:RangesMember
799 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
800 Top of range [member] Member ifrs-full:TopOfRangeMember
801 Classes of property, plant and equipment [axis] Axis ifrs-full:ClassesOfPropertyPlantAndEquipmentAxis
802 Property, plant and equipment [member] Member ifrs-full:PropertyPlantAndEquipmentMember
803 Irape enterprise [member] Member xcmig:IrapeEnterpriseMember
804 Queimadao Consortium Enterprise [member] Member xcmig:QueimadaoConsortiumEnterpriseMember
805 Salto morais small hydro plant enterprise [member] Member xcmig:SaltoMoraisSmallHydroPlantEnterpriseMember
806 Rio de Pedras Small Hydro Plant Enterprise [member] Member xcmig:RioDePedrasSmallHydroPlantEnterpriseMember
807 Various Small Hydro Plants Enterprise [member] Member xcmig:VariousSmallHydroPlantsEnterpriseMember
808 Disclosure of concession and amount to be paid [Line Items] LineItems xcmig:DisclosureOfConcessionAndAmountToBePaidLineItems
809 Percentage interest Concept (Percent) For Period xcmig:PercentageOfConcessionInterest
810 Nominal value in 2017 Concept (Monetary) As Of Credit xcmig:ConcessionNominalValue
811 Present value in 2017 Concept (Monetary) As Of Credit xcmig:ConcessionPresentValue
812 Amortization period Concept (Text/String) For Period xcmig:AmortizationPeriod
813 Inflation index to be used to adjust historical amounts Concept (Text/String) For Period xcmig:InflationIndexToBeUsedToAdjustHistoricalAmounts
814 1082 - Disclosure - Concessions and Authorizations - Schedule of Present Value and Nominal Value Portion to be paid (Detail) Network

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815 Disclosure of present value and nominal value portion to be paid [Table] Table

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 xcmig:DisclosureOfPresentValueAndNominalValuePortionToBePaidTable
816 Classes of property, plant and equipment [axis] Axis ifrs-full:ClassesOfPropertyPlantAndEquipmentAxis
817 Property, plant and equipment [member] Member ifrs-full:PropertyPlantAndEquipmentMember
818 Irape enterprise [member] Member xcmig:IrapeEnterpriseMember
819 Queimadao Consortium Enterprise [member] Member xcmig:QueimadaoConsortiumEnterpriseMember
820 Salto Morais, Rio de Pedras and Others [member] Member xcmig:SaltoMoraisRioDePedrasAndOthersEnterpriseMember
821 Disclosure Of Present Value And Nominal Value Portion To Be Paid [Line Items] LineItems xcmig:DisclosureOfPresentValueAndNominalValuePortionToBePaidLineItems
822 Percentage interest Concept (Percent) For Period xcmig:PercentageOfConcessionInterest
823 Amounts paid in 2017 Concept (Monetary) For Period Debit xcmig:ConcessionAmountPaid
824 Present value of amounts to be paid in 12 months Concept (Monetary) As Of Credit xcmig:PresentValueOfConcessionAmountsToBePaidInNextTwelveMonths
825 Nominal value of amounts to be paid in 12 months Concept (Monetary) As Of Credit xcmig:NominalValueOfAmountsToBePaidInNextTwelveMonths
826 1083 - Disclosure - Operating Segments - Schedule of Operating Revenues, Costs and Expenses (Detail) Network

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 http://imetrix.edgar-online.com/taxonomy/role/DisclosureOperatingSegmentsScheduleOfOperatingRevenuesCostsAndExpenses
827 Disclosure of operating segments [table] Table

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 ifrs-full:DisclosureOfOperatingSegmentsTable
828 Segments [axis] Axis ifrs-full:SegmentsAxis
829 Segments [member] Member ifrs-full:SegmentsMember
830 Electricity Generation [member] Member xcmig:GenerationSegmentMember
831 Electricity Transmission [member] Member xcmig:TransmissionSegmentMember
832 Electricity Distribution [member] Member xcmig:DistributionSegmentMember
833 Telecoms [member] Member xcmig:TelecommunicationsSegmentMember
834 Gas [member] Member xcmig:GasAndPowerSegmentMember
835 Other [member] Member ifrs-full:AllOtherSegmentsMember
836 Segment consolidation items [axis] Axis ifrs-full:SegmentConsolidationItemsAxis
837 Entity's total for segment consolidation items [member] Member ifrs-full:EntitysTotalForSegmentConsolidationItemsMember
838 Operating Segments [member] Member ifrs-full:OperatingSegmentsMember
839 Eliminations [member] Member ifrs-full:EliminationOfIntersegmentAmountsMember
840 Disclosure of operating segments [line items] LineItems ifrs-full:DisclosureOfOperatingSegmentsLineItems
841 SEGMENT ASSETS Concept (Monetary) As Of Debit xcmig:AssetsOne
842 INVESTMENTS IN ASSOCIATES AND JOINTLY-CONTROLLED ENTITIES Concept (Monetary) As Of Debit ifrs-full:InvestmentsInSubsidiariesJointVenturesAndAssociates
843 ADDITIONS TO THE SEGMENT Concept (Monetary) For Period Debit xcmig:AdditionsToSegment
844 ADDITIONS TO FINANCIAL ASSETS Concept (Monetary) For Period Debit ifrs-full:AdditionsToNoncurrentAssets
845 NET REVENUE Concept (Monetary) For Period Credit ifrs-full:Revenue
846 COST OF ELECTRICITY AND GAS Abstract xcmig:CostOfEnergyAndGasAbstract
847 Electricity for purchased for sale Concept (Monetary) For Period Debit xcmig:ElectricityPurchasedForResale
848 Charges for the use of the national grid Concept (Monetary) For Period Debit xcmig:NationalGridUsageCharges
849 Gas bought for resale Concept (Monetary) For Period Debit xcmig:GasPurchasedForResaleOne
850 Operating costs Concept (Monetary) For Period Debit xcmig:OperatingCosts
851 OPERATING COSTS AND EXPENSES Abstract xcmig:OtherCostAbstract
852 Personnel Concept (Monetary) For Period Debit xcmig:PersonnelExpensesOne
853 Employees' and managers' profit sharing Concept (Monetary) For Period Debit xcmig:ExpenseFromSharebasedPaymentTransactionsWithEmployeesOne
854 Post-retirement liabilities Concept (Monetary) For Period Credit xcmig:PostRetirementLiabilities
855 Materials Concept (Monetary) For Period Debit ifrs-full:RawMaterialsAndConsumablesUsed
856 Raw materials and inputs for production of electricity Concept (Monetary) For Period Debit xcmig:RawMaterialsAndInputsForProductionOfElectricity
857 Outsourced services Concept (Monetary) For Period Debit xcmig:OutsourcedServicesExpense
858 Depreciation and amortization Concept (Monetary) For Period Debit xcmig:AdjustmentsForDepreciationAndAmortisationExpenseOne
859 Operating provisions (reversals) Concept (Monetary) For Period Debit xcmig:AdjustmentsForProvisionsOne
860 Construction costs Concept (Monetary) For Period Debit xcmig:ConstructionContractsCosts
861 Other operating expenses, net Concept (Monetary) For Period Credit xcmig:MiscellaneousOtherOperatingIncomeExpenseOne
862 Total cost of operation Concept (Monetary) For Period Debit xcmig:CostsChargedToOperatingProfit
863 OPERATING COSTS AND EXPENSES Concept (Monetary) For Period Debit xcmig:CostsAndExpenses1
864 OPERATING INCOME BEFORE EQUITY GAINS (LOSSES) AND FINANCE INCOME (EXPENSES) Concept (Monetary) For Period Credit xcmig:OperatingProfitBeforeEquityGainsLossesAndFinancialRevenue
865 Equity in earnings of unconsolidated investees, net Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
866 Adjustment for loss of value in Investments Concept (Monetary) For Period Credit xcmig:AdjustmentForLossOfValueInInvestments
867 Fair value results in Corporate Operation Concept (Monetary) For Period Credit xcmig:FairValueGainLossOnStockholdingTransaction
868 Finance income Concept (Monetary) For Period Credit ifrs-full:FinanceIncome
869 Finance expenses Concept (Monetary) For Period Debit ifrs-full:FinanceCosts
870 Income before income tax and social contribution tax Concept (Monetary) For Period Credit ifrs-full:ProfitLossBeforeTax
871 Income and Social Contribution taxes Concept (Monetary) For Period Debit ifrs-full:IncomeTaxExpenseContinuingOperations
872 NET INCOME (LOSS) FOR THE YEAR Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromContinuingOperations
873 OTHER COMPREHENSIVE INCOME Abstract ifrs-full:OtherComprehensiveIncomeAbstract
874 Items that will not be reclassified to profit or loss Abstract ifrs-full:ComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTaxAbstract
875 Post retirement liabilities - restatement of obligations of the defined benefit plans, net of taxes Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeNetOfTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans
876 Equity gain (loss) on Other comprehensive income in jointly-controlled entities Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeNetOfTaxGainsLossesFromInvestmentsInEquityInstruments
877 Other comprehensive income that will not be reclassified to profit or loss, net of tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax
878 Items that may be reclassified to profit or loss Abstract ifrs-full:ComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTaxAbstract
879 Conversion adjustment of equity gain (loss) in other comprehensive income in subsidiary and jointly-controlled entity Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeNetOfTaxAvailableforsaleFinancialAssets
880 Items that may be reclassified to profit or loss Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax
881 Recycling of conversion adjustments to the Income statement arising from sale of Transchile Concept (Monetary) For Period Debit xcmig:ReclassificationAdjustmentsOnExchangeDifferencesOnTranslationNetOfTaxOne
882 COMPREHENSIVE INCOME FOR THE YEAR Concept (Monetary) For Period Credit xcmig:ComprehensiveIncomeOne
883 Controlling shareholders Concept (Monetary) For Period Credit xcmig:ComprehensiveIncomeAttributableToOwnersOfParentOne
884 Non-controlling shareholder Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncomeAttributableToNoncontrollingInterests
885 1084 - Disclosure - Operating Segments - Schedule of Operating Revenues, Costs and Expenses (Parenthetical) (Detail) Network

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886 Implied Table Table

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 implied:Table
887 Disclosure of operating segments [abstract] Abstract ifrs-full:DisclosureOfOperatingSegmentsAbstract
888 Operating provision expense Concept (Monetary) For Period Debit xcmig:OperatingProvisionExpense
889 1085 - Disclosure - Cash and Cash Equivalents - Summary of Cash and Cash Equivalents (Detail) Network

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 http://imetrix.edgar-online.com/taxonomy/role/DisclosureCashAndCashEquivalentsSummaryOfCashAndCashEquivalents
890 Implied Table Table

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*

 implied:Table
891 Cash and cash equivalents [abstract] Abstract ifrs-full:CashAndCashEquivalentsAbstract
892 Bank accounts Concept (Monetary) As Of Debit ifrs-full:BalancesWithBanks
893 Cash equivalents Abstract ifrs-full:CashEquivalentsAbstract
894 Bank certificates of deposit (CDBs) Concept (Monetary) As Of Debit ifrs-full:ShorttermDepositsClassifiedAsCashEquivalents
895 Overnight Concept (Monetary) As Of Debit xcmig:OvernightMarketClassifiedAsCashAndCashEquivalents
896 Others Concept (Monetary) As Of Debit ifrs-full:OtherCashAndCashEquivalents
897 Short term investments Concept (Monetary) As Of Debit ifrs-full:ShorttermInvestmentsClassifiedAsCashEquivalents
898 Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
899 1086 - Disclosure - Cash and Cash Equivalents - Summary of Cash and Cash Equivalents (Parenthetical) (Detail) Network

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900 Cash And Cash Equivalents [Table] Table

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 xcmig:CashAndCashEquivalentsTable
901 Investment Type [Axis] Axis us-gaap:InvestmentTypeAxis
902 Investments [Domain] Member us-gaap:InvestmentTypeCategorizationMember
903 Bank certificates of deposit [member] Member xcmig:BankCertificateOfDepositsMember
904 Range [axis] Axis ifrs-full:RangeAxis
905 Ranges [member] Member ifrs-full:RangesMember
906 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
907 Top of range [member] Member ifrs-full:TopOfRangeMember
908 Cash and Cash Equivalents [Line Items] LineItems xcmig:CashAndCashEquivalents1LineItems
909 Percentage of accrued interest on certificate of deposits Concept (Percent) For Period xcmig:PercentageOfFloatingRateOnCashDeposit
910 Percentage of fixed interest rate Concept (Percent) For Period xcmig:PercentageOfFixedInterestRateOnCashDeposit
911 1087 - Disclosure - Securities - Schedule of Cash Investments (Detail) Network

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912 Disclosure of investment securities [Table] Table

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 xcmig:DisclosureOfInvestmentSecuritiesTable
913 Investment [Axis] Axis invest:InvestmentAxis
914 Investment [Domain] Member invest:InvestmentDomain
915 Bank certificates of deposit [member] Member xcmig:BankCertificateOfDepositsMember
916 Financial Notes-Banks [member] Member xcmig:FinancialNotesBanksMember
917 Treasury financial notes (LFTs) [member] Member xcmig:TreasuryFinancialNotesMember
918 Debentures [member] Member xcmig:DebenturesMember
919 Other [member] Member xcmig:OtherInvestmentMember
920 Disclosure of investment securities [Line Items] LineItems xcmig:DisclosureOfInvestmentSecuritiesLineItems
921 Current investments Concept (Monetary) As Of Debit xcmig:ShortTermSecurities
922 Non-current investments Concept (Monetary) As Of Debit xcmig:LongTermSecurities
923 Investments Concept (Monetary) As Of Debit xcmig:ShortTermAndLongTermSecurities
924 1088 - Disclosure - Securities - Schedule of Cash Investments (Parenthetical) (Detail) Network

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 http://imetrix.edgar-online.com/taxonomy/role/DisclosureSecuritiesScheduleOfCashInvestmentsParenthetical
925 Disclosure of investment securities [Table] Table

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 xcmig:DisclosureOfInvestmentSecuritiesTable
926 Investment Type [Axis] Axis us-gaap:InvestmentTypeAxis
927 Investments [Domain] Member us-gaap:InvestmentTypeCategorizationMember
928 Bank certificates of deposit [member] Member xcmig:BankCertificateOfDepositsMember
929 Range [axis] Axis ifrs-full:RangeAxis
930 Ranges [member] Member ifrs-full:RangesMember
931 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
932 Top of range [member] Member ifrs-full:TopOfRangeMember
933 Types of interest rates [axis] Axis ifrs-full:TypesOfInterestRatesAxis
934 Interest rate types [member] Member ifrs-full:InterestRateTypesMember
935 Fixed And Floating Interest Rate [member] Member xcmig:FixedAndFloatingInterestRateMember
936 Financial Notes-Banks [member] Member xcmig:FinancialNotesBanksMember
937 Debentures [member] Member xcmig:DebenturesMember
938 Disclosure of investment securities [Line Items] LineItems xcmig:DisclosureOfInvestmentSecuritiesLineItems
939 Investment rate remunerated at percentage of rate for interbank deposits Concept (Percent) For Period xcmig:InvestmentSecuritiesRateRemuneratedAtPercentageOfRateForInterbankDeposits
940 1089 - Disclosure - Customers, Traders and Power Transport Concession Holders - Summary of Trade and Other Receivables (Detail) Network

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941 Disclosure of Trade and Other Receivables [Table] Table

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 xcmig:DisclosureOfTradeAndOtherReceivablesTable
942 Maturity [axis] Axis ifrs-full:MaturityAxis
943 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
944 Balances not yet due [member] Member xcmig:BalancesNotYetDueMember
945 Up to 90 days past due [member] Member ifrs-full:NotLaterThanThreeMonthsMember
946 More than 90 days past due [member] Member ifrs-full:LaterThanThreeMonthsMember
947 Disclosure of trade and other receivables [Line Items] LineItems xcmig:DisclosureOfTradeAndOtherReceivablesLineItems
948 Billed supply Concept (Monetary) As Of Debit xcmig:BilledSupply
949 Unbilled supply Concept (Monetary) As Of Debit xcmig:UnbilledSupply
950 Other concession holders - wholesale supply Concept (Monetary) As Of Debit xcmig:WholesaleSupplyToOtherConcessionHolders
951 Other concession holders - wholesale supply, unbilled Concept (Monetary) As Of Debit xcmig:WholesaleSupplyToOtherConcessionHoldersUnbilled
952 CCEE (Wholesale Trading Exchange) Concept (Monetary) As Of Debit xcmig:ElectricityWholesaleTradingExchangeReceivables
953 Concession Holders - power transport Concept (Monetary) As Of Debit xcmig:ConcessionHoldersTransportOfElectricity
954 Concession Holders - power transport, unbilled Concept (Monetary) As Of Debit xcmig:ConcessionHoldersPowerTransportUnbilled
955 (-) Provision for doubtful receivables Concept (Monetary) As Of Credit ifrs-full:AllowanceAccountForCreditLossesOfFinancialAssets
956 Trade and other receivables Concept (Monetary) As Of Debit ifrs-full:TradeAndOtherReceivables
957 Current assets Concept (Monetary) As Of Debit xcmig:CurrentCustomersAndTradersAndConcessionHoldersTransportOfElectricity
958 Non-current assets Concept (Monetary) As Of Debit xcmig:NoncurrentCustomersAndTradersAndConcessionHoldersTransportOfElectricity
959 1090 - Disclosure - Customers, Traders and Power Transport Concession Holders - Summary of Provision for Allowance for Doubtful Accounts (Detail) Network

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960 Disclosure of financial assets [table] Table

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 ifrs-full:DisclosureOfFinancialAssetsTable
961 Classes of financial instruments [axis] Axis ifrs-full:ClassesOfFinancialInstrumentsAxis
962 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
963 Residential [member] Member xcmig:ResidentialMember
964 Industrial [member] Member xcmig:IndustrialMember
965 Commercial, services and others [member] Member xcmig:CommercialServicesAndOtherMember
966 Rural [member] Member xcmig:RuralMember
967 Public authorities [member] Member xcmig:PublicAuthoritiesMember
968 Public Lighting [member] Member xcmig:PublicLightingMember
969 Public service [member] Member xcmig:PublicServiceMember
970 Charges for use of the network-TUSD [member] Member xcmig:NetworkFeesMember
971 Other [member] Member xcmig:OtherReceivablesMember
972 Disclosure of financial assets [line items] LineItems ifrs-full:DisclosureOfFinancialAssetsLineItems
973 Allowance account for credit losses of financial assets Concept (Monetary) As Of Credit ifrs-full:AllowanceAccountForCreditLossesOfFinancialAssets
974 1091 - Disclosure - Customers, Traders and Power Transport Concession Holders - Summary of Changes in Provision for Doubtful Accounts (Detail) Network

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975 Implied Table Table

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 implied:Table
976 Changes in allowance account for credit losses of financial assets [abstract] Abstract ifrs-full:ChangesInAllowanceAccountForCreditLossesOfFinancialAssetsAbstract
977 Beginning balance Concept (Monetary) As Of Credit ifrs-full:AllowanceAccountForCreditLossesOfFinancialAssets
978 Additions, net Concept (Monetary) For Period ifrs-full:AdditionalAllowanceRecognisedInProfitOrLossAllowanceAccountForCreditLossesOfFinancialAssets
979 Written off Concept (Monetary) For Period ifrs-full:ReversalAllowanceAccountForCreditLossesOfFinancialAssets
980 Ending balance Concept (Monetary) As Of Credit ifrs-full:AllowanceAccountForCreditLossesOfFinancialAssets
981 1092 - Disclosure - Customers, Traders and Power Transport Concession Holders - Summary of Advances from Customers (Detail) Network

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982 Disclosure Of Advances From Customers [table] Table

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 xcmig:DisclosureOfAdvancesFromCustomersTable
983 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
984 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
985 Cemig GT [member] Member xcmig:CemigGTMember
986 Disclosure Of Advances From Customers [line items] LineItems xcmig:DisclosureOfAdvancesFromCustomersLineItems
987 Beginning Balance Concept (Monetary) As Of Credit ifrs-full:CurrentAdvances
988 Addition Concept (Monetary) For Period Credit xcmig:AdditionsToAdvancesPayable
989 Supply completed Concept (Monetary) For Period Debit xcmig:SupplyOfEnergyCompleted
990 Monetary adjustment Concept (Monetary) For Period Credit xcmig:MonetaryAdjustmentOnAdvancePayable
991 Ending Balance Concept (Monetary) As Of Credit ifrs-full:CurrentAdvances
992 1093 - Disclosure - Customers, Traders and Power Transport Concession Holders - Summary of Terms of Advances from Clients (Detail) Network

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993 Disclosure Of Advances From Customers [table] Table

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 xcmig:DisclosureOfAdvancesFromCustomersTable
994 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
995 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
996 Cemig GT [member] Member xcmig:CemigGTMember
997 Counterparties [axis] Axis ifrs-full:CounterpartiesAxis
998 Counterparties [member] Member ifrs-full:CounterpartiesMember
999 BTG Pactual [member] Member xcmig:BTGPactualMember
1000 BTG Pactual1 [member] Member xcmig:BTGPactual1Member
1001 Deal Comercializadora [member] Member xcmig:DealComercializadoraMember
1002 White Martins Gases Industriais Ltda [member] Member xcmig:WhiteMartinsGasesIndustriaisLtdaMember
1003 White Martins Gases Industriais Ltda1 [member] Member xcmig:WhiteMartinsGasesIndustriaisLtda1Member
1004 Disclosure Of Advances From Customers [line items] LineItems xcmig:DisclosureOfAdvancesFromCustomersLineItems
1005 Specified period for billing Concept (Text/String) For Period xcmig:SpecifiedPeriodForBillingOfAdvancesReceived
1006 Index for adjusting prepaid amounts Concept (Text/String) For Period xcmig:IndexForAdjustingOfPrepaidAmountsDescription
1007 GWh deliverable Concept (num:energyItemType) For Period xcmig:DeliverableEnergyUnit
1008 Advances from clients Concept (Monetary) As Of Credit ifrs-full:CurrentAdvances
1009 1094 - Disclosure - Recoverable Taxes - Summary of Recoverable Taxes (Detail) Network

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1010 Disclosure of recoverable taxes [Table] Table

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1011 Classes of acquired receivables [axis] Axis ifrs-full:ClassesOfAcquiredReceivablesAxis
1012 Classes of acquired receivables [member] Member ifrs-full:ClassesOfAcquiredReceivablesMember
1013 ICMS (VAT) [member] Member xcmig:ICMSVATMember
1014 PIS and Pasep taxes [member] Member xcmig:PISAndPaseptaxesMember
1015 Cofins [member] Member xcmig:CofinsTaxMember
1016 Other [member] Member xcmig:OtherTaxRecoverableMember
1017 Disclosure of Recoverable Taxes [Line Items] LineItems xcmig:DisclosureOfRecoverableTaxesLineItems
1018 Recoverable taxes, current Concept (Monetary) As Of Debit xcmig:CurrentRecoverableTaxes
1019 Recoverable taxes, non-current Concept (Monetary) As Of Debit xcmig:NoncurrentRecoverableTaxes
1020 Recoverable taxes Concept (Monetary) As Of Debit xcmig:RecoverableTaxes
1021 1095 - Disclosure - Income and Social Contribution Taxes - Summary of Income and Social Contribution Taxes recoverable (Detail) Network

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1022 Implied Table Table

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1023 Disclosure of income and social contribution taxes [Abstract] Abstract xcmig:DisclosureOfIncomeAndSocialContributionTaxesAbstract
1024 Income tax Concept (Monetary) As Of Debit xcmig:IncomeTaxCurrent
1025 Social contribution tax Concept (Monetary) For Period xcmig:SocialContributionTaxCurrent
1026 Income and social contribution tax credits current Concept (Monetary) For Period Debit xcmig:IncomeAndSocialContributionTaxCreditsCurrent
1027 Income tax Concept (Monetary) For Period Debit xcmig:IncomeTaxNonCurrent
1028 Social contribution tax Concept (Monetary) For Period Debit xcmig:SocialContributionTaxNonCurrent
1029 Income and social contribution tax credits noncurrent Concept (Monetary) For Period Debit xcmig:IncomeAndSocialContributionTaxCreditsNoncurrent
1030 Income and social contribution tax credits Concept (Monetary) As Of Debit xcmig:IncomeAndSocialContributionTaxCredits
1031 1096 - Disclosure - Income and Social Contribution Taxes - Additional Information (Detail) Network

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1032 Implied Table Table

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1033 Disclosure Of Income And Social Contribution Taxes Recoverable [Abstract] Abstract xcmig:DisclosureOfIncomeAndSocialContributionTaxesRecoverableAbstract
1034 Tax credits for income tax Concept (Percent) For Period ifrs-full:ApplicableTaxRate
1035 Social contribution tax rate Concept (Percent) For Period xcmig:SocialContributionTaxRate
1036 Tax loss and negative tax-balance carryforwards, limitation percentage Concept (Percent) For Period xcmig:TaxLossAndNegativeTaxbalanceCarryforwardsLimitationPercentage
1037 1097 - Disclosure - Income and Social Contribution Taxes - Summary of Deferred Income and Social Contribution Taxes (Detail) Network

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1038 Disclosure of Income and Social Contribution Taxes Recoverable [Table] Table

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 xcmig:DisclosureOfIncomeAndSocialContributionTaxesRecoverableTable
1039 Temporary difference, unused tax losses and unused tax credits [axis] Axis ifrs-full:TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsAxis
1040 Temporary difference, unused tax losses and unused tax credits [member] Member ifrs-full:TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsMember
1041 Tax loss carry forwards [member] Member xcmig:TaxLossCarryForwardsMember
1042 Provisions [member] Member xcmig:ProvisionsMember
1043 Post-retirement obligations [member] Member xcmig:PostretirementLiabilitiesMember
1044 Estimated provision for doubtful receivables [member] Member xcmig:EstimatedProvisionForDoubtfulReceivablesMember
1045 Taxes with suspended liability [member] Member xcmig:TaxesWithSuspendedLiabilityMember
1046 Paid concession [member] Member xcmig:PaidConcessionMember
1047 Adjustment to fair value: Swap/loss [member] Member xcmig:AdjustmentToFairValueSwapLossMember
1048 Other [member] Member xcmig:OtherDeferredIncomeAndSocialContributionTaxesAssetsMember
1049 Funding cost [member] Member xcmig:FundingCostMember
1050 Deemed cost [member] Member xcmig:DeemedCostMember
1051 Cost of acquisition of equity interests [member] Member xcmig:CostOfAcquisitionOfEquityInterestsMember
1052 Borrowing costs capitalized [member] Member xcmig:BorrowingCostsCapitalizedMember
1053 Taxes on revenues not redeemed - Presumed Profit accounting method [member] Member xcmig:TaxesOnRevenuesNotRedeemedPresumedProfitAccountingMethodMember
1054 Transmission assets: Indemnity gain [member] Member xcmig:TransmissionAssetsIndemnityGainMember
1055 Adjustment of expectation of cash flow from the indemnifiable Financial asset of distribution concession [member] Member xcmig:AdjustmentOfExpectationOfCashFlowFromTheIndemnifiableFinancialAssetOfDistributionConcessionMember
1056 Other Deferred Income And Social Contribution Taxes Liabilities [member] Member xcmig:OtherDeferredIncomeAndSocialContributionTaxesLiabilitiesMember
1057 Disclosure of income and social contribution taxes recoverable [Line Items] LineItems xcmig:DisclosureOfIncomeAndSocialContributionTaxesRecoverableLineItems
1058 Deferred tax liabilities Concept (Monetary) As Of Credit xcmig:DeferredIncomeAndSocialContributionTaxesLiabilities
1059 Total, net Concept (Monetary) For Period Debit xcmig:DeferredIncomeTaxAssetAndSocialContributionTaxes
1060 Total assets Concept (Monetary) As Of Debit xcmig:DeferredIncomeTaxAssetsAndSocialContributionTaxNoncurrent
1061 Total liabilities Concept (Monetary) As Of Credit xcmig:NoncurrentPayablesOnSocialSecurityAndTaxes
1062 Deferred tax assets Concept (Monetary) As Of Debit xcmig:DeferredIncomeAndSocialContributionTaxesAssets
1063 1098 - Disclosure - Income and Social Contribution Taxes - Summary of Changes in Deferred Income and Social Contribution Taxes (Detail) Network

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1064 Implied Table Table

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1065 Disclosure of deferred income and social contribution taxes [Abstract] Abstract xcmig:DisclosureOfDeferredIncomeAndSocialContributionTaxesAbstract
1066 Beginning balance Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilityAsset
1067 Effects allocated to Statement of income Concept (Monetary) For Period ifrs-full:DeferredTaxExpenseIncomeRecognisedInProfitOrLoss
1068 Effects allocated to Statement of comprehensive income Concept (Monetary) For Period ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncome
1069 Realized Concept (Monetary) For Period Credit xcmig:IncreaseDecreaseThroughRealizedDeferredTaxLiabilityAsset
1070 Variations in deferred tax assets and liabilities Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseInDeferredTaxLiabilityAsset
1071 Ending balance Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilityAsset
1072 1099 - Disclosure - Income and Social Contribution Taxes - Summary of Estimated Balance of Deferred Tax Asset (Detail) Network

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1073 Disclosure Of Future Taxable Profits Enable Deferred Tax Assets [Table] Table

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1074 Maturity [axis] Axis ifrs-full:MaturityAxis
1075 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
1076 2018 [member] Member ifrs-full:NotLaterThanOneYearMember
1077 2019 [member] Member ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMember
1078 2020 [member] Member ifrs-full:LaterThanTwoYearsAndNotLaterThanThreeYearsMember
1079 2021 [member] Member ifrs-full:LaterThanThreeYearsAndNotLaterThanFourYearsMember
1080 2022 [member] Member ifrs-full:LaterThanFourYearsAndNotLaterThanFiveYearsMember
1081 2022-2024 [member] Member ifrs-full:LaterThanFiveYearsAndNotLaterThanSevenYearsMember
1082 2025-2026 [Member] Member ifrs-full:LaterThanSevenYearsAndNotLaterThanTenYearsMember
1083 Disclosure Of Future Taxable Profits Enable Deferred Tax Assets [Line Items] LineItems xcmig:DisclosureOfFutureTaxableProfitsEnableDeferredTaxAssetsLineItems
1084 Deferred tax assets future taxable profits Concept (Monetary) As Of Debit xcmig:DeferredIncomeAndSocialContributionTaxesAssets
1085 1100 - Disclosure - Income and Social Contribution Taxes - Summary of Reconciliation of Statutory on Income and Social Contribution Taxes (Detail) Network

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1086 Implied Table Table

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1087 Disclosure Of Reconciliation Of Expense On Income And Social Contribution Taxes [Abstract] Abstract xcmig:DisclosureOfReconciliationOfExpenseOnIncomeAndSocialContributionTaxesAbstract
1088 Profit before income and Social Contribution taxes Concept (Monetary) For Period Credit ifrs-full:AccountingProfit
1089 Income tax and Social Contribution tax - nominal expense Concept (Monetary) For Period Debit ifrs-full:TaxExpenseIncomeAtApplicableTaxRate
1090 Tax effects applicable to: Abstract ifrs-full:ReconciliationOfAccountingProfitMultipliedByApplicableTaxRatesAbstract
1091 Gain (loss) in subsidiaries by equity method (net of effects of Interest on Equity) Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfAssociatesAccountedForUsingEquityMethod
1092 Interest on Equity Concept (Monetary) For Period Debit xcmig:TaxEffectOfDeductionsFromInterestOnEquity
1093 Gain on formation of Alianca Geracao Concept (Monetary) As Of Debit xcmig:GainOnFormationOfJointlyControlledCompany
1094 Gain on dilution of an equity interest Concept (Monetary) For Period Debit xcmig:TaxEffectGainOnDilutionOfAnEquityInterest
1095 Deduction - Intangible assets of concession amortized - capital gain -Taesa Concept (Monetary) For Period Credit xcmig:DeductionOfAmortizedIntangibleConcessionAssetsCapitalGain
1096 Non-deductiblecontributions and donations Concept (Monetary) For Period Debit xcmig:NondeductibleContributionAndDonations
1097 Tax incentives Concept (Monetary) For Period Debit xcmig:TaxEffectOfTaxIncentives
1098 Tax credits not recognized Concept (Monetary) For Period Debit xcmig:TaxEffectOfTaxCreditsNotRecognised
1099 Difference between Presumed Profit and Real Profit Concept (Monetary) For Period Debit xcmig:TaxEffectOfDifferenceBetweenPresumedProfitAndRealProfit
1100 Non-deductiblepenalties Concept (Monetary) For Period Debit xcmig:NondeductiblePenalties
1101 Excess reactive power and demand Concept (Monetary) For Period Debit xcmig:ExcessOnReactivePowerAndDemandLevels
1102 Write-down of part of estimated losses for doubtful debtors Concept (Monetary) For Period Debit xcmig:TaxEffectOfWritedownOfForPartOfAllowanceForDoubtfulDebtors
1103 Others Concept (Monetary) For Period Debit ifrs-full:OtherTaxEffectsForReconciliationBetweenAccountingProfitAndTaxExpenseIncome
1104 Income tax and Social Contribution - effective gain (expense) Concept (Monetary) For Period Debit ifrs-full:IncomeTaxExpenseContinuingOperations
1105 Current tax Concept (Monetary) For Period Debit ifrs-full:CurrentTaxExpenseIncome
1106 Deferred tax Concept (Monetary) For Period Debit ifrs-full:DeferredTaxExpenseIncome
1107 Income tax and Social Contribution - effective gain (expense) Concept (Monetary) For Period Debit ifrs-full:IncomeTaxExpenseContinuingOperations
1108 Effective rate Concept (Percent) For Period ifrs-full:AverageEffectiveTaxRate
1109 1101 - Disclosure - Restricted Cash - Additional Information (Detail) Network

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1110 Implied Table Table

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1111 Disclosure Of Restricted Cash And Cash Equivalents [Abstract] Abstract xcmig:DisclosureOfRestrictedCashAndCashEquivalentsAbstract
1112 Restricted cash Concept (Monetary) As Of Debit ifrs-full:RestrictedCashAndCashEquivalents
1113 1102 - Disclosure - Accounts Receivable from The State of Minas Gerais - Additional Information (Detail) Network

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1114 Implied Table Table

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1115 Disclosure of accounts receivables [abstract] Abstract xcmig:DisclosureOfAccountsReceivablesAbstract
1116 Reimburse from minas gerais state government Concept (Monetary) As Of Debit xcmig:ReimburseFromMinasGeraisStateGovernment
1117 Historical amount from minas gerais state government Concept (Monetary) As Of Debit xcmig:HistoricalAmountFromMinasGeraisStateGovernment
1118 Monetary adjustment from minas gerais state government Concept (Monetary) As Of Debit xcmig:MonetaryAdjustmentFromMinasGeraisStateGovernment
1119 Payment description from Minas Gerais state government Concept (Text/String) For Period xcmig:PaymentDescriptionFromMinasGeraisStateGovernment
1120 Amounts Received from Minas Gerais state government Concept (Monetary) For Period Credit xcmig:AmountsReceivedFromMinasGeraisStateGovernment
1121 Remaining amounts receivable from Minas Gerais state government Concept (Monetary) For Period Debit xcmig:RemainingAmountsReceivableFromMinasGeraisStateGovernment
1122 1103 - Disclosure - Escrow Deposits - Schedule of Payments Related to Escrow Deposits (Detail) Network

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1123 Implied Table Table

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1124 Disclosure of escrow deposits [Abstract] Abstract xcmig:DisclosureOfEscrowDepositsAbstract
1125 Labor claims Concept (Monetary) As Of Debit xcmig:EscrowDepositsLaborClaims
1126 Tax contingencies Abstract xcmig:EscrowDepositsTaxContingenciesAbstract
1127 Income tax on Interest on Equity Concept (Monetary) As Of Debit xcmig:IncomeTaxOnInterestOnEquity
1128 Pasep and Cofins taxes (1) Concept (Monetary) As Of Debit xcmig:PasepAndCofinsTax
1129 ICMS (VAT) credits on PP&E Concept (Monetary) As Of Debit xcmig:IcmsCreditsOnPropertyPlantAndEquipment
1130 Donations and legacy tax (ITCD) Concept (Monetary) As Of Debit xcmig:DonationsAndLegacyTax
1131 Urban property tax (IPTU) Concept (Monetary) As Of Debit xcmig:UrbanPropertyTax
1132 Finsocial tax Concept (Monetary) As Of Debit xcmig:FinSocialTax
1133 Income and Social Contr. Tax on indemnity for employees' 'Anuênio' benefit Concept (Monetary) As Of Debit xcmig:IncomeAndSocialContributionTaxOnIndemnityForEmployeesAnuenioBenefit
1134 Others Concept (Monetary) As Of Debit xcmig:EscrowDepositsOtherTaxIssues
1135 Escrow deposits tax issues, Total Concept (Monetary) As Of Debit xcmig:EscrowDepositsTaxIssues
1136 Others Abstract xcmig:EscrowDepositsOtherAbstract
1137 Monetary updating on AFAC - Minas Gerais state government (3) Concept (Monetary) As Of Debit xcmig:MonetaryUpdatingOnAfacFromMinasGeraisStateGovernment
1138 Regulatory Concept (Monetary) As Of Debit xcmig:RegulatoryEscrowDeposits
1139 Third party Concept (Monetary) As Of Debit xcmig:ThirdPartyEscrowDeposits
1140 Customer relations Concept (Monetary) As Of Debit xcmig:CustomerRelationsEscrowDeposits
1141 Court embargo Concept (Monetary) As Of Debit xcmig:CourtEmbargoEscrowDeposits
1142 Others Concept (Monetary) As Of Debit xcmig:OtherEscrowDeposits
1143 Escrow deposits other Concept (Monetary) As Of Debit xcmig:EscrowDepositsOther
1144 Long term escrow deposit Concept (Monetary) As Of Debit xcmig:LongTermEscrowDeposit
1145 1104 - Disclosure - Reimbursement Of Tariff Subsidies - Additional Information (Detail) Network

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1146 Disclosure Of Energy Development Accounts [Table] Table

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*

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1147 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
1148 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
1149 Cemig D [member] Member xcmig:CemigDMember
1150 Disclosure Of Energy Development Account [Line Items] LineItems xcmig:DisclosureOfEnergyDevelopmentAccountLineItems
1151 Subsidies revenue recognized Concept (Monetary) As Of Debit xcmig:SubsidiesRevenueRecognized
1152 Current subsidy receivable Concept (Monetary) As Of Debit xcmig:CurrentSubsidyReceivable
1153 1105 - Disclosure - Concession Financial Assets and Liabilities - Summary of Financial Assets and Liabilities of Concession (Detail) Network

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1154 Disclosure Of Financial Assets And Liabilities of The Concession [Table] Table

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 xcmig:DisclosureOfFinancialAssetsAndLiabilitiesOfTheConcessionTable
1155 Types of financial assets [axis] Axis ifrs-full:TypesOfFinancialAssetsAxis
1156 Financial assets, type [member] Member ifrs-full:FinancialAssetsTypeMember
1157 Financial assets [member] Member xcmig:AssetsRelatedToInfrastuctureMember
1158 Service concession arrangements [axis] Axis ifrs-full:ServiceConcessionArrangementsAxis
1159 Service concession arrangements [member] Member ifrs-full:ServiceConcessionArrangementsMember
1160 Distribution concessions [member] Member xcmig:DistributionsConcessionsMember
1161 Transmission concessions [member] Member xcmig:TransmissionConcessionsMember
1162 Transmission receivable [Member] Member xcmig:TransmissionReceivableMember
1163 Generation receivable [Member] Member xcmig:GenerationReceivableMember
1164 Concession Grant Fee [Member] Member xcmig:ConcessionGrantFeeMember
1165 CVA and Other Financial Components in Tariff Adjustments [member] Member xcmig:CVAAndOtherFinancialComponentsInTariffAdjustmentsMember
1166 Disclosure Of Financial Assets and Liabilities Of The Concession [Line Items] LineItems xcmig:DisclosureOfFinancialAssetsAndLiabilitiesOfTheConcessionLineItems
1167 Financial assets of the concession Abstract xcmig:DisclosureOfFinancialAssetsOfTheConcessionAbstract
1168 Financial assets Concept (Monetary) As Of Debit ifrs-full:FinancialAssets
1169 Current assets Concept (Monetary) As Of Debit ifrs-full:CurrentFinancialAssets
1170 Non-current assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssets
1171 Financial liabilities of the concession Abstract xcmig:DisclosureOfFinancialLiabilitiesOfTheConcessionAbstract
1172 CVA (Portion A Compensation) Account and Other Financial Components in tariff adjustments Concept (Monetary) As Of Credit ifrs-full:FinancialLiabilities
1173 Current liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentFinancialLiabilities
1174 Non-current liabilities Concept (Monetary) As Of Credit ifrs-full:NoncurrentFinancialLiabilities
1175 1106 - Disclosure - Concession Financial Assets and Liabilities - Summary of Changes in Concession Financial Assets (Detail) Network

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1176 Disclosure of financial assets [table] Table

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1177 Classes of financial assets [axis] Axis ifrs-full:ClassesOfFinancialAssetsAxis
1178 Financial assets, class [member] Member ifrs-full:FinancialAssetsMember
1179 Infrastructure [Member] Member xcmig:InfrastructureMember
1180 Types of rate-regulated activities [axis] Axis ifrs-full:TypesOfRateregulatedActivitiesAxis
1181 Rate-regulated activities [member] Member ifrs-full:RateregulatedActivitiesMember
1182 Transmission [member] Member xcmig:TransmissionMember
1183 Generation [member] Member xcmig:GenerationMember
1184 Distribution [member] Member xcmig:DistributionMember
1185 Disclosure of financial assets [line items] LineItems ifrs-full:DisclosureOfFinancialAssetsLineItems
1186 Beginning Balance Concept (Monetary) As Of Debit xcmig:InfrastructureFinancialAssets
1187 Additions Concept (Monetary) For Period Debit ifrs-full:AdditionsToNoncurrentAssets
1188 Transfers of indemnity - plants not renewed Concept (Monetary) As Of Debit xcmig:TransfersOfIndemnityPlantsNotRenewed
1189 Addition - Grant Fee - Plants Concept (Monetary) For Period Debit xcmig:AdditionGrantFeePlants
1190 Disposals Concept (Monetary) As Of Debit ifrs-full:FinancialAssetsWrittenOffDuringReportingPeriodAndStillSubjectToEnforcementActivityContractualAmountOutstanding
1191 Transfer from Financial assets to Intangible assets on renewal of concessions Concept (Monetary) As Of Debit xcmig:TransferFromFinancialAssetsToIntangibleAssetsOnRenewalOfConcessions
1192 Transfers Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughTransfersFinancialAssets
1193 Generation residual value receivable Concept (Monetary) For Period Debit xcmig:GenerationResidualValueReceivable
1194 Amounts received Concept (Monetary) For Period Credit ifrs-full:ConsiderationPaidReceived
1195 Transfers between PP&E, Financial assets and Intangible Assets Concept (Monetary) As Of Debit xcmig:TransfersBetweenPropertyPlantAndEquipmentFinancialAssetsAndIntangibleAssets
1196 Monetary updating Concept (Monetary) As Of Debit xcmig:MonetaryUpdating
1197 Updating of the Concession Grant Fee Concept (Monetary) For Period Debit xcmig:UpdatingOfResidualValueOfAssets
1198 Adjustment of expectation of cash flow from the Concession financial assets Concept (Monetary) For Period Credit ifrs-full:AdjustmentsForGainsLossesOnFairValueAdjustmentInvestmentProperty
1199 Updating of residual value of assets Concept (Monetary) For Period Debit xcmig:UpdatingOfIndemnifiedValueOfAssets
1200 Adjustment of BRR of Transmission Assets (Note 26) Concept (Monetary) For Period Credit xcmig:AdjustmentOfBrrOfTransmissionAssets
1201 Adjustment on indemnities of plants not renewed (Ministerial Order 291) - including financial updating Concept (Monetary) For Period Credit xcmig:AdjustmentOnIndemnitiesOfPlantsNotRenewed
1202 Ending Balance Concept (Monetary) As Of Debit xcmig:InfrastructureFinancialAssets
1203 1107 - Disclosure - Concession Financial Assets and Liabilities - Additional Information (Detail) Network

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1204 Disclosure Of Financial Assets And Liabilities of The Concession [Table] Table

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 xcmig:DisclosureOfFinancialAssetsAndLiabilitiesOfTheConcessionTable
1205 Property, plant and equipment by operating lease status [axis] Axis ifrs-full:PropertyPlantAndEquipmentByOperatingLeaseStatusAxis
1206 Property, plant and equipment by operating lease status [member] Member ifrs-full:PropertyPlantAndEquipmentByOperatingLeaseStatusMember
1207 Hydro electric Plant [member] Member xcmig:HydroElectricPlantMember
1208 Non-adjusting events after reporting period [axis] Axis ifrs-full:NonadjustingEventsAfterReportingPeriodAxis
1209 Non-adjusting events after reporting period [member] Member ifrs-full:NonadjustingEventsMember
1210 Other disposals of assets [member] Member ifrs-full:OtherDisposalsOfAssetsMember
1211 Classes of financial instruments [axis] Axis ifrs-full:ClassesOfFinancialInstrumentsAxis
1212 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
1213 Customer Charges - Tariff Flag Amounts [member] Member xcmig:TariffFlagMember
1214 Sales channels [axis] Axis ifrs-full:SalesChannelsAxis
1215 Sales channels [member] Member ifrs-full:SalesChannelsMember
1216 Regulated market [member] Member xcmig:RegulatedMarketMember
1217 Electricity acquired in the Free Market [member] Member xcmig:FreeMarketMember
1218 Service concession arrangements [axis] Axis ifrs-full:ServiceConcessionArrangementsAxis
1219 Service concession arrangements [member] Member ifrs-full:ServiceConcessionArrangementsMember
1220 Transmission Indemnity receivable [member] Member xcmig:TransmissionIndemnityReceivableMember
1221 Types of financial assets [axis] Axis ifrs-full:TypesOfFinancialAssetsAxis
1222 Financial assets, type [member] Member ifrs-full:FinancialAssetsTypeMember
1223 Financial assets [member] Member xcmig:AssetsRelatedToInfrastuctureMember
1224 Consolidated Entities [Axis] Axis us-gaap:ConsolidatedEntitiesAxis
1225 Consolidated Entities [Domain] Member us-gaap:ConsolidatedEntitiesDomain
1226 Subsidiaries [member] Member ifrs-full:SubsidiariesMember
1227 Types of investment property [axis] Axis ifrs-full:TypesOfInvestmentPropertyAxis
1228 Investment property [member] Member ifrs-full:InvestmentPropertyMember
1229 Jaguara hydroelectric plant [member] Member xcmig:JaguaraHydroelectricPlantMember
1230 Sao simao hydroelectric plant [member] Member xcmig:SaoSimaoHydroelectricPlantMember
1231 Miranda hydroelectric plant [member] Member xcmig:MirandaHydroelectricPlantMember
1232 Disclosure Of Financial Assets and Liabilities Of The Concession [Line Items] LineItems xcmig:DisclosureOfFinancialAssetsAndLiabilitiesOfTheConcessionLineItems
1233 Homologated amount Concept (Monetary) As Of Debit xcmig:PortionOfTheReversibleAssetsNotYetAmortized
1234 Financial assets Concept (Monetary) As Of Debit ifrs-full:FinancialAssets
1235 Remuneration payment period Concept (xbrli:durationItemType) For Period xcmig:RemunerationPaymentPeriod
1236 Extensions of concessions, tariff maximum amount Concept (Monetary) For Period Debit xcmig:ConcessionExtensionTariffMaximum
1237 Extension of the concessions Concept (Monetary) For Period Debit xcmig:ConcessionExtensionOfRemunerationCostOfCapital
1238 Adjustment of BRR of transmission assets Concept (Monetary) For Period Credit xcmig:AdjustmentOfBrrOfTransmissionAssets
1239 Transmission assets receivable Concept (Monetary) For Period Credit xcmig:TransmissionAssetsReceivable
1240 Adjusted regulatory remuneration base of assets Concept (Monetary) As Of Debit xcmig:RegulatoryRemunerationAdjusted
1241 Net balance of assets deemed cost Concept (Monetary) As Of Debit xcmig:NetBalanceOfAssetsDeemedCost
1242 Investments Concept (Monetary) As Of Debit ifrs-full:InvestmentsInAssociatesAccountedForUsingEquityMethod
1243 Output sales percentage Concept (Percent) For Period xcmig:OutputSalesPercentage
1244 Grant acquisition period Concept (xbrli:durationItemType) For Period xcmig:GrantAcquisitionPeriod
1245 Number of plants Concept (Integer) For Period xcmig:NumberOfPlants
1246 Cost of acquisition Concept (Monetary) As Of Debit xcmig:CostOfAcquisition
1247 Acquisition payment percentage Concept (Percent) For Period xcmig:AcquisitionPaymentPercentage
1248 Remaining 35% of acquisition payment Concept (Monetary) For Period Credit xcmig:RemainingAcquisitionPayment
1249 Remaining 35% of acquisition payment updated Concept (Monetary) For Period Credit xcmig:RemainingAcquisitionPaymentUpdated
1250 Pass-throughs of funds Concept (Monetary) For Period Debit xcmig:OtherPassThroughCosts
1251 1108 - Disclosure - Concession Financial Assets and Liabilities - Summary of Indemnity Values (Detail) Network

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1252 Disclosure Of Financial Assets And Liabilities of The Concession [Table] Table

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1253 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
1254 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
1255 Cemig GT [member] Member xcmig:CemigGTMember
1256 Service concession arrangements [axis] Axis ifrs-full:ServiceConcessionArrangementsAxis
1257 Service concession arrangements [member] Member ifrs-full:ServiceConcessionArrangementsMember
1258 Transmission Indemnity receivable [member] Member xcmig:TransmissionIndemnityReceivableMember
1259 Disclosure Of Financial Assets and Liabilities Of The Concession [Line Items] LineItems xcmig:DisclosureOfFinancialAssetsAndLiabilitiesOfTheConcessionLineItems
1260 Adjustment of the BRR of Transmission Assets - Aneel Technical Note 183/2017 Concept (Monetary) For Period Credit xcmig:AdjustmentOfBrrOfTransmissionAssets
1261 Regulatory Remuneration Base (BRR) - Dispatch 2,181 2016 Concept (Monetary) As Of Debit xcmig:RegulatoryRemunerationBase
1262 Updating per MME Concept (Monetary) As Of Debit xcmig:UpdatedValueByInflationAndCostOfOwnCapital
1263 Monetary adjustment Concept (Monetary) For Period Credit xcmig:MonetaryAdjustment
1264 Amounts received Concept (Monetary) As Of Debit xcmig:AmountOfTheIndemnityReceivedSoFar
1265 Net residual value of the assets to be received Concept (Monetary) As Of Debit xcmig:NetResidualValueOfAssets
1266 Total indemnity Concept (Monetary) As Of Debit xcmig:Indemnity
1267 1109 - Disclosure - Concession Financial Assets and Liabilities - Summary of Generation Indemnity Receivable (Detail) Network

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1268 Disclosure Of Financial Assets And Liabilities of The Concession [Table] Table

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1269 Property, plant and equipment by operating lease status [axis] Axis ifrs-full:PropertyPlantAndEquipmentByOperatingLeaseStatusAxis
1270 Property, plant and equipment by operating lease status [member] Member ifrs-full:PropertyPlantAndEquipmentByOperatingLeaseStatusMember
1271 Tres Marias Hydroelectric Plant [member] Member xcmig:TresMariasHydroelectricPlantMember
1272 Salto Grande Hydroelectric Plant [member] Member xcmig:SaltoGrandeHydroelectricPlantMember
1273 Itutinga Hydroelectric Plant [member] Member xcmig:ItutingaHydroelectricPlantMember
1274 Camargos hydroelectric plant [member] Member xcmig:CamargosHydroelectricPlantMember
1275 Piau Small Hydroelectric Plant [member] Member xcmig:PiauSmallHydroelectricPlantMember
1276 Gafanhoto Small Hydroelectric Plant [member] Member xcmig:GafanhotoSmallHydroelectricPlantMember
1277 Peti Small Hydroelectric Plant [member] Member xcmig:PetiSmallHydroelectricPlantMember
1278 Dona Rita Small Hydroelectric Plant [member] Member xcmig:DonaRitaSmallHydroelectricPlantMember
1279 Tronqueiras Small Hydroelectric Plant [member] Member xcmig:TronqueirasSmallHydroelectricPlantMember
1280 Joasal Small Hydroelectric Plant [member] Member xcmig:JoasalSmallHydroelectricPlantMember
1281 Martins Small Hydroelectric Plant [member] Member xcmig:MartinsSmallHydroelectricPlantMember
1282 Cajuru Small Hydroelectric Plant [member] Member xcmig:CajuruSmallHydroelectricPlantMember
1283 Paciencia Small Hydroelectric Plant [member] Member xcmig:PacienciaSmallHydroelectricPlantMember
1284 Marmelos Small Hydroelectric Plant [member] Member xcmig:MarmelosSmallHydroelectricPlantMember
1285 Volta grande hydroelectric plant [member] Member xcmig:VoltaGrandeHydroelectricPlantMember
1286 Miranda hydroelectric plant [member] Member xcmig:MirandaHydroelectricPlantMember
1287 Jaguara hydroelectric plant [member] Member xcmig:JaguaraHydroelectricPlantMember
1288 Sao simao hydroelectric plant [member] Member xcmig:SaoSimaoHydroelectricPlantMember
1289 Classes of property, plant and equipment [axis] Axis ifrs-full:ClassesOfPropertyPlantAndEquipmentAxis
1290 Property, plant and equipment [member] Member ifrs-full:PropertyPlantAndEquipmentMember
1291 Miranda and Sao Simao hydroelectric plants [member] Member xcmig:MirandaAndSaoSimaoHydroelectricPlantsMember
1292 Types of investment property [axis] Axis ifrs-full:TypesOfInvestmentPropertyAxis
1293 Investment property [member] Member ifrs-full:InvestmentPropertyMember
1294 Miranda hydroelectric plant [member] Member xcmig:MirandaHydroelectricPlantMember
1295 Sao simao hydroelectric plant [member] Member xcmig:SaoSimaoHydroelectricPlantMember
1296 Disclosure Of Financial Assets and Liabilities Of The Concession [Line Items] LineItems xcmig:DisclosureOfFinancialAssetsAndLiabilitiesOfTheConcessionLineItems
1297 Concession expiration date Concept (Year/Month) For Period xcmig:ConcessionExpirationDate
1298 Installed capacity (MW) Concept (num:powerItemType) For Period xcmig:InstalledCapacity
1299 Net balance of assets based on historical cost Concept (Monetary) As Of Debit xcmig:NetBalanceOfAssetsHistoricCost
1300 Net balance of assets based on fair value (replacement cost) Concept (Monetary) As Of Debit xcmig:NetBalanceOfAssetsDeemedCost
1301 Residual value of assets of basis project based on replacement of cost at December 2017 Concept (Monetary) As Of Debit xcmig:NetBalanceOfAssetsBasicPlanDeemedCost
1302 Adjustment Concept (Monetary) As Of Credit xcmig:AdjustmentOfNonamortizedBalanceOfConcessions
1303 Amounts based on MME Order 291 (A)+(B) Concept (Monetary) As Of Debit xcmig:NetBalanceOfAssetsBasicPlanDeemedCostAfterAdjustments
1304 Monitory adjustment (C) Concept (Monetary) As Of Debit xcmig:MonetaryUpdating
1305 Residual value of assets of basis project at 2017 Concept (Monetary) As Of Debit xcmig:NetBalanceOfAssetsBasicPlan
1306 1110 - Disclosure - Concession Financial Assets and Liabilities - Summary of Generation Indemnity Receivable (Parenthetical) (Detail) Network

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1307 Disclosure Of Financial Assets And Liabilities of The Concession [Table] Table

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 xcmig:DisclosureOfFinancialAssetsAndLiabilitiesOfTheConcessionTable
1308 Classes of property, plant and equipment [axis] Axis ifrs-full:ClassesOfPropertyPlantAndEquipmentAxis
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1310 Miranda and Sao Simao hydroelectric plants [member] Member xcmig:MirandaAndSaoSimaoHydroelectricPlantsMember
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1312 Monetary updating Concept (Monetary) As Of Debit xcmig:MonetaryUpdating
1313 Adjustment of MME of transmission assets Concept (Monetary) For Period Credit xcmig:AdjustmentOfMMEOfTransmissionAssets
1314 1111 - Disclosure - Concession Financial Assets and Liabilities - Summary of Auction Won Transferred to Related Specific Purpose Companies (Detail) Network

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1315 Disclosure Of Financial Assets And Liabilities of The Concession [Table] Table

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1316 Service concession arrangements [axis] Axis ifrs-full:ServiceConcessionArrangementsAxis
1317 Service concession arrangements [member] Member ifrs-full:ServiceConcessionArrangementsMember
1318 Cemig Geracao Tres Marias SA [member] Member xcmig:CemigGeracaoTresMariasSAMember
1319 Cemig Geracao Salto Grande SA [member] Member xcmig:CemigGeracaoSaltoGrandeSAMember
1320 Cemig Geracao Itutinga SA [member] Member xcmig:CemigGeracaoItutingaSAMember
1321 Cemig Geracao Camargos SA [member] Member xcmig:CemigGeracaoCamargosSAMember
1322 Cemig Geracao Sul S.A. [member] Member xcmig:CemigGeracaoSulSAMember
1323 Cemig Geracao Leste SA [member] Member xcmig:CemigGeracaoLesteSAMember
1324 Cemig Geracao Oeste S.A. [member] Member xcmig:CemigGeracaoOesteSAMember
1325 Disclosure Of Financial Assets and Liabilities Of The Concession [Line Items] LineItems xcmig:DisclosureOfFinancialAssetsAndLiabilitiesOfTheConcessionLineItems
1326 Beginning Balance Concept (Monetary) As Of Debit xcmig:AuctionConcession
1327 Monetary updating Concept (Monetary) As Of Debit xcmig:MonetaryUpdating
1328 Amounts received Concept (Monetary) For Period Credit ifrs-full:ConsiderationPaidReceived
1329 Ending Balance Concept (Monetary) As Of Debit xcmig:AuctionConcession
1330 1112 - Disclosure - Concession Financial Assets and Liabilities - Summary of Financial Assets and Financial Liabilities With the Tariff Adjustments (Detail) Network

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1331 Disclosure Of Financial Assets And Financial Liabilities With The Tariff Adjustments [table] Table

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1334 CVA account for compensation of changes in portion A costs [member] Member xcmig:CVAAccountForCompensationOfChangesInPortionACostsMember
1335 Classes of financial instruments [axis] Axis ifrs-full:ClassesOfFinancialInstrumentsAxis
1336 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
1337 Quota for the Energy Development Account [member] Member xcmig:QuotaForTheEnergyDevelopmentAccountMember
1338 Tariff for Use of Transmission Facilities of Grid Participants [member] Member xcmig:TariffForUseOfTransmissionFacilitiesOfGridParticipantsMember
1339 Tariff for Transport of Electricity Provided by Itaiputs [member] Member xcmig:TariffForTransportOfElectricityProvidedByItaiputsMember
1340 Program to Encourage Alternative Sources of Electricity Proinfa [member] Member xcmig:ProgramToEncourageAlternativeSourcesOfElectricityProinfaMember
1341 System Service Charges and Reserve Energy Charge [member] Member xcmig:SystemServiceChargesAndReserveEnergyChargeMember
1342 Electricity Purchased for Resale [member] Member xcmig:ElectricityPurchasedForResaleMember
1343 Overcontracting of Supply [member] Member xcmig:OvercontractingOfSupplyMember
1344 Neutrality of Portion A [member] Member xcmig:NeutralityOfPortionAMember
1345 Other Financial Items [member] Member xcmig:OtherFinancialItemsMember
1346 Customer Charges - Tariff Flag Amounts [member] Member xcmig:TariffFlagMember
1347 Excess demand and reactive power [member] Member xcmig:ExcessDemandAndReactivePowerMember
1348 Classes of assets [axis] Axis ifrs-full:ClassesOfAssetsAxis
1349 Assets [member] Member ifrs-full:ClassesOfAssetsMember
1350 Amounts ratified by Aneel in the last tariff adjustment [member] Member xcmig:AmountsRatifiedByAneelInTheLastTariffAdjustmentMember
1351 Amounts ratified by Aneel in the next tariff adjustment [member] Member xcmig:AmountsRatifiedByAneelInTheNextTariffAdjustmentMember
1352 Disclosure Of Financial Assets and Financial Liabilities [line items] LineItems xcmig:DisclosureOfFinancialAssetsAndFinancialLiabilitiesLineItems
1353 Assets Concept (Monetary) As Of Debit ifrs-full:FinancialAssets
1354 Current assets Concept (Monetary) As Of Debit ifrs-full:CurrentFinancialAssets
1355 Non-current assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssets
1356 Liabilities Concept (Monetary) As Of Credit ifrs-full:FinancialLiabilities
1357 Current liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentFinancialLiabilities
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1361 Alternative power source program (Proinfa) Concept (Monetary) As Of Debit xcmig:FinancialAssetsLiabilitiesNet
1362 1113 - Disclosure - Concession Financial Assets and Liabilities - Summary of Financial Assets and Financial Liabilities With the Tariff Adjustments (Parenthetical) (Detail) Network

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1363 Disclosure Of Financial Assets And Financial Liabilities With The Tariff Adjustments [table] Table

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 xcmig:DisclosureOfFinancialAssetsAndFinancialLiabilitiesWithTheTariffAdjustmentsTable
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1366 CVA account for compensation of changes in portion A costs [member] Member xcmig:CVAAccountForCompensationOfChangesInPortionACostsMember
1367 Disclosure Of Financial Assets and Financial Liabilities [line items] LineItems xcmig:DisclosureOfFinancialAssetsAndFinancialLiabilitiesLineItems
1368 Excess on energy reserve account Concept (Monetary) As Of Credit xcmig:ExcessOnEnergyReserveAccount
1369 1114 - Disclosure - Concession Financial Assets and Liabilities - Summary of Changes in Balances of Financial Assets and Liabilities (Detail) Network

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1370 Implied Table Table

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1371 Disclosure Of Financial Assets And Financial Liabilities With The Tariff Adjustments [Abstract] Abstract xcmig:DisclosureOfFinancialAssetsAndFinancialLiabilitiesWithTheTariffAdjustmentsAbstract
1372 Beginning balance Concept (Monetary) As Of Debit ifrs-full:NetAssetsLiabilities
1373 Net constitution of financial liabilities Concept (Monetary) For Period Debit xcmig:NewFinancialAssetsConstituted
1374 Additions Concept (Monetary) For Period Debit xcmig:AdditionsFinancialAssetsLiabilities
1375 Amortization Concept (Monetary) For Period Debit xcmig:Amortization
1376 Receipt of funds from the ACR Account and from the Centralizing Account for Funds from the Tariff Flag System-CCRBT Concept (Monetary) For Period Debit xcmig:ReceiptOfFunds
1377 Payments from the Flag Tariff Centralizing Account Concept (Monetary) For Period Credit xcmig:PaymentsFromTheTariffFlag
1378 Transfer Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughTransfersFinancialAssets
1379 Updating - Selic rate Concept (Monetary) For Period Debit xcmig:UpdatingSelicRate
1380 Ending balance Concept (Monetary) As Of Debit ifrs-full:NetAssetsLiabilities
1381 1115 - Disclosure - Investments - Percentage of the Company's Equity Interest (Detail) Network

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1382 Disclosure of detailed information about investment property [table] Table

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1383 Classes of assets [axis] Axis ifrs-full:ClassesOfAssetsAxis
1384 Assets [member] Member ifrs-full:ClassesOfAssetsMember
1385 Investments accounted for using equity method [member] Member ifrs-full:InvestmentsAccountedForUsingEquityMethodMember
1386 Types of investment property [axis] Axis ifrs-full:TypesOfInvestmentPropertyAxis
1387 Investment property [member] Member ifrs-full:InvestmentPropertyMember
1388 Hidreletrica Cachoeirao [member] Member xcmig:HidreletricaCachoeiraoMember
1389 Guanhaes energia [member] Member xcmig:GuanhaesEnergiaMember
1390 Hidreletrica Pipoca [member] Member xcmig:HidreletricaPipocaMember
1391 Retiro Baixo [member] Member xcmig:RetiroBaixoMember
1392 Alianca Norte [member] Member xcmig:AliancaNorteMember
1393 Madeira Energia [member] Member xcmig:MadeiraEnergiaMember
1394 Fip Melbourne [member] Member xcmig:FipMelbourneMember
1395 Lightger [member] Member xcmig:LightGerMember
1396 Baguari Energia [member] Member xcmig:BaguariEnergiaMember
1397 Renova [member] Member xcmig:RenovaMember
1398 Alianca Geracao [member] Member xcmig:AliancaGeracaoMember
1399 Central Eolica Praias de Parajuru [member] Member xcmig:CentralEolicaPraiasDeParajuruMember
1400 Central Eolica Volta do Rio [member] Member xcmig:CentralEolicaVoltaDoRioMember
1401 Central Eolica Praias de Morgado [member] Member xcmig:CentralEolicaPraiasDeMorgadoMember
1402 Amazonia Energia [member] Member xcmig:AmazoniaEnergiaMember
1403 Usina Hidreletrica Itaocara SA [member] Member xcmig:UsinaHidreletricaItaocaraSAMember
1404 Light [member] Member xcmig:LightMember
1405 Taesa [member] Member xcmig:TaesaMember
1406 Ativas Data Center [member] Member xcmig:AtivasDataCenterMember
1407 Lepsa [member] Member xcmig:LepsaMember
1408 RME [member] Member xcmig:RmeMember
1409 Companhia Transleste de Transmissao [member] Member xcmig:CompanhiaTranslestedeTransmissaoMember
1410 Companhia Transudeste de Transmissao [member] Member xcmig:CompanhiaTransudestedeTransmissaoMember
1411 Companhia Transirape de Transmissao [member] Member xcmig:CompanhiaTransirapedeTransmissaoMember
1412 Companhia de Transmissao Centroeste de Minas [member] Member xcmig:CompanhiadeTransmissaoCentroestedeMinasMember
1413 Axxiom Solucoes Tecnologicas [Member] Member xcmig:AxxiomSolucoesTecnologicasMember
1414 Guanhaes [Member] Member xcmig:GuanhaesMember
1415 Disclosure of detailed information about investment property [line items] LineItems ifrs-full:DisclosureOfInvestmentPropertyLineItems
1416 Description of how acquirer obtained control of acquiree Concept (Text/String) For Period ifrs-full:DescriptionOfHowAcquirerObtainedControlOfAcquiree
1417 Investments in associates accounted for using equity method gross Concept (Monetary) As Of Debit xcmig:InvestmentsInAssociatesAccountedForUsingEquityMethodGross
1418 Investments in associates accounted for using equity method Concept (Monetary) As Of Debit ifrs-full:InvestmentsInAssociatesAccountedForUsingEquityMethod
1419 1116 - Disclosure - Investments - Allocation of Acquisition Price of Jointly-Controlled Subsidiaries, A Valuation was Made of Intangible Assets Relating to Right to Operate Regulated Activity (Detail) Network

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1420 Disclosure of detailed information about investment property [table] Table

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 ifrs-full:DisclosureOfInvestmentPropertyTable
1421 Types of investment property [axis] Axis ifrs-full:TypesOfInvestmentPropertyAxis
1422 Investment property [member] Member ifrs-full:InvestmentPropertyMember
1423 Taesa [member] Member xcmig:TaesaMember
1424 Light [member] Member xcmig:LightMember
1425 Gasmig [member] Member xcmig:GasmigMember
1426 Lepsa [member] Member xcmig:LepsaMember
1427 RME [member] Member xcmig:RmeMember
1428 Disclosure of detailed information about investment property [line items] LineItems ifrs-full:DisclosureOfInvestmentPropertyLineItems
1429 Beginning balance Concept (Monetary) As Of Debit ifrs-full:InvestmentProperty
1430 Addition Concept (Monetary) For Period Debit ifrs-full:AdditionsOtherThanThroughBusinessCombinationsInvestmentProperty
1431 Amortization Concept (Monetary) For Period Debit xcmig:AmortizationInvestmentProperty
1432 Written off Concept (Monetary) For Period Debit xcmig:WrittenOffOfInvestments
1433 Ending balance Concept (Monetary) As Of Debit ifrs-full:InvestmentProperty
1434 1117 - Disclosure - Investments - Movement of Investments in the Jointly-controlled Entities (Detail) Network

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1435 Disclosure of detailed information about investment property [table] Table

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 ifrs-full:DisclosureOfInvestmentPropertyTable
1436 Types of investment property [axis] Axis ifrs-full:TypesOfInvestmentPropertyAxis
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1438 Companhia Transleste de Transmissao [member] Member xcmig:CompanhiaTranslestedeTransmissaoMember
1439 Companhia Transudeste de Transmissao [member] Member xcmig:CompanhiaTransudestedeTransmissaoMember
1440 Companhia Transirape de Transmissao [member] Member xcmig:CompanhiaTransirapedeTransmissaoMember
1441 Transchile Charrua Transmision SA [Member] Member xcmig:TranschileMember
1442 Companhia de Transmissao Centroeste de Minas [member] Member xcmig:CompanhiadeTransmissaoCentroestedeMinasMember
1443 Light [member] Member xcmig:LightMember
1444 Axxiom Solucoes Tecnologicas [Member] Member xcmig:AxxiomSolucoesTecnologicasMember
1445 Hidreletrica Cachoeirao [member] Member xcmig:HidreletricaCachoeiraoMember
1446 Guanhaes energia [member] Member xcmig:GuanhaesEnergiaMember
1447 Hidreletrica Pipoca [member] Member xcmig:HidreletricaPipocaMember
1448 Madeira Energia [member] Member xcmig:MadeiraEnergiaMember
1449 Fip Melbourne [member] Member xcmig:FipMelbourneMember
1450 Lightger [member] Member xcmig:LightGerMember
1451 Baguari Energia [member] Member xcmig:BaguariEnergiaMember
1452 Central Eolica Praias de Parajuru [member] Member xcmig:CentralEolicaPraiasDeParajuruMember
1453 Central Eolica Volta do Rio [member] Member xcmig:CentralEolicaVoltaDoRioMember
1454 Central Eolica Praias de Morgado [member] Member xcmig:CentralEolicaPraiasDeMorgadoMember
1455 Amazonia Energia [member] Member xcmig:AmazoniaEnergiaMember
1456 Ativas Data Center [member] Member xcmig:AtivasDataCenterMember
1457 Epicaresempreend Imentos [Member] Member xcmig:EpicaresEmpreendimentosMember
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1461 Alianca Geracao [member] Member xcmig:AliancaGeracaoMember
1462 Alianca Norte [member] Member xcmig:AliancaNorteMember
1463 Retiro Baixo [member] Member xcmig:RetiroBaixoMember
1464 Luce [member] Member xcmig:LuceMember
1465 RME [member] Member xcmig:RmeMember
1466 Usina Hidreletrica Itaocara SA [member] Member xcmig:UsinaHidreletricaItaocaraSAMember
1467 Companhia De Transmissa Centroeste De Minas [member] Member xcmig:CompanhiaDeTransmissaCentroesteDeMinasMember
1468 Lepsa [member] Member xcmig:LepsaMember
1469 Disclosure of detailed information about investment property [line items] LineItems ifrs-full:DisclosureOfInvestmentPropertyLineItems
1470 Beginning balance Concept (Monetary) As Of Debit xcmig:InvestmentsInAssociatesAccountedForUsingEquityMethodGross
1471 Equity method gain (Statement of income) Concept (Monetary) For Period Credit xcmig:GainLossOnSaleOfInvestmentSecuritiesGross
1472 Equity method gain(Other comprehensive income) Concept (Monetary) For Period Credit xcmig:InvestmentUnrealisedGainLossGross
1473 Dividends Concept (Monetary) For Period Debit xcmig:DividendsFromAssociatesGross
1474 Injections / acquisitions Concept (Monetary) For Period Debit xcmig:AdditionsFromAcquisitionsInvestmentPropertyGross
1475 Sales Concept (Monetary) For Period Debit xcmig:IncreaseDecreaseThroughDisposalOfInvestmentsAccountedForUsingEquityMethodGross
1476 Incorporation Concept (Monetary) For Period Debit xcmig:IncreaseDecreaseThroughIncorporationOfInvestmentsAccountedForUsingEquityMethodGross
1477 Other Concept (Monetary) For Period Debit xcmig:IncreaseDecreaseThroughOtherChangesInvestmentPropertyGross
1478 Ending balance Concept (Monetary) As Of Debit xcmig:InvestmentsInAssociatesAccountedForUsingEquityMethodGross
1479 Beginning balance Concept (Monetary) As Of Debit ifrs-full:InvestmentsInAssociatesAccountedForUsingEquityMethod
1480 Beginning balance Concept (Monetary) As Of Credit xcmig:InvestmentsInAssociatesAccountedForUsingEquityMethodUncoveredLiabilities
1481 Equity method gain (Statement of income) Concept (Monetary) For Period Credit xcmig:EquityMethodGainLoss
1482 Other Concept (Monetary) For Period Credit xcmig:IncreaseDecreaseThroughOtherChangesInvestmentPropertyUncoveredLiabilities
1483 Equity method gain(Other comprehensive income) Concept (Monetary) As Of Debit xcmig:InvestmentUnrealisedGainLossNet
1484 Ending balance Concept (Monetary) As Of Credit xcmig:InvestmentsInAssociatesAccountedForUsingEquityMethodUncoveredLiabilities
1485 Dividends Concept (Monetary) For Period Debit xcmig:DividendsFromAssociates
1486 Injections / acquisitions Concept (Monetary) For Period Debit ifrs-full:AdditionsFromAcquisitionsInvestmentProperty
1487 Sales Concept (Monetary) For Period Credit xcmig:IncreaseDecreaseThroughDisposalOfInvestmentsAccountedForUsingEquityMethod
1488 Incorporation Concept (Monetary) For Period Debit xcmig:IncreaseDecreaseThroughIncorporationOfInvestmentsAccountedForUsingEquityMethod
1489 Other Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughOtherChangesInvestmentProperty
1490 Ending balance Concept (Monetary) As Of Debit ifrs-full:InvestmentsInAssociatesAccountedForUsingEquityMethod
1491 1118 - Disclosure - Investments - Movement of Investments in the Jointly-controlled Entities (Parenthetical) (Detail) Network

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1492 Implied Table Table

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1493 Disclosure of detailed information about investment property [abstract] Abstract ifrs-full:DisclosureOfInvestmentPropertyAbstract
1494 Dilution of shareholding interest Concept (Monetary) For Period Debit xcmig:DilutionOfShareholderInterest
1495 The impairment of intangible concession assets Concept (Monetary) For Period ifrs-full:ImpairmentLossRecognisedInProfitOrLossIntangibleAssetsOtherThanGoodwill
1496 1119 - Disclosure - Investments - Principal Information on the Subsidiaries and Jointly-Controlled Entities (Detail) Network

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1497 Disclosure of Investments in Subsidiaries Joint Ventures and Associates [Table] Table

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1498 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
1499 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
1500 Subsidiaries and jointly-controlled entities [member] Member xcmig:SubsidiariesAndJointlycontrolledEntitiesMember
1501 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
1502 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
1503 Cemig Geracaoe Transmissao S A [member] Member xcmig:CemigGeracaoeTransmissaoSAMember
1504 Hidreletrica Cachoeirao SA [member] Member xcmig:HidreletricaCachoeiraoSAMember
1505 Guanhaes Energia SA [member] Member xcmig:GuanhaesEnergiaSAMember
1506 Hidreletrica Pipoca [member] Member xcmig:HidreletricaPipocaMember
1507 Retiro Baixo Energtica SA [member] Member xcmig:RetiroBaixoEnergticaSAMember
1508 Alianca Norte Energia Participacoes S A [member] Member xcmig:AliancaNorteEnergiaParticipacoesSAMember
1509 Madeira Energia SA [member] Member xcmig:MadeiraEnergiaSAMember
1510 Lightger SA [member] Member xcmig:LightgerSAMember
1511 Baguari Energia SA [member] Member xcmig:BaguariEnergiaSAMember
1512 Renova Energia SA [member] Member xcmig:RenovaEnergiaSAMember
1513 Alianca Geracao de Energia [member] Member xcmig:AliancaGeracaodeEnergiaMember
1514 Central Eolica Praias de Parajuru SA [member] Member xcmig:CentralEolicaPraiasdeParajuruSAMember
1515 Central Eolica Volta do Rio SA [member] Member xcmig:CentralEolicaVoltadoRioSAMember
1516 Central Eolica Praias de Morgado [member] Member xcmig:CentralEolicaPraiasDeMorgadoMember
1517 Amazonia energia participacoes S A [member] Member xcmig:AmazoniaEnergiaParticipacoesSAMember
1518 Usina Hidreletrica Itaocara SA [member] Member xcmig:UsinaHidreletricaItaocaraSAMember
1519 Cemig Distribuicao [member] Member xcmig:CemigDistribuicaoSAMember
1520 Light SA [member] Member xcmig:LightSAMember
1521 Cemig Telecom [member] Member xcmig:CemigTelecomMember
1522 Rosal Energia SA [member] Member xcmig:RosalEnergiaSAMember
1523 Sa Carvalho S A [member] Member xcmig:SaCarvalhoSAMember
1524 Companhiade Gasde Minas Gerais [member] Member xcmig:CompanhiadeGasdeMinasGeraisMember
1525 Horizontes Energia SA [member] Member xcmig:HorizontesEnergiaSAMember
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1529 Rio Minas Energia Participacoes SA [member] Member xcmig:RioMinasEnergiaParticipacoesSAMember
1530 Companhia Transleste de Transmissao [member] Member xcmig:CompanhiaTranslestedeTransmissaoMember
1531 UTE Barreiro SA [member] Member xcmig:UTEBarreiroSAMember
1532 Companhia Transudeste de Transmissao [member] Member xcmig:CompanhiaTransudestedeTransmissaoMember
1533 Empresa de Comercializacao de Energia Eletrica [member] Member xcmig:EmpresadeComercializacaodeEnergiaEletricaMember
1534 Companhia Transirape de Transmissao [member] Member xcmig:CompanhiaTransirapedeTransmissaoMember
1535 Transchile Charrua Transmision SA [Member] Member xcmig:TranschileMember
1536 Efficientia SA [Member] Member xcmig:EfficientiaSAMember
1537 Cemig Comercializadora de Energia Incentivada [member] Member xcmig:CemigComercializadoradeEnergiaIncentivadaSAMember
1538 Companhia de Transmissao Centroeste de Minas [member] Member xcmig:CompanhiadeTransmissaoCentroestedeMinasMember
1539 Cemig Trading SA [member] Member xcmig:CemigTradingSAMember
1540 Axxiom solucoesTecnologicas S.A. [member] Member xcmig:AxxiomSolucoesTecnologicasSAMember
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1549 1120 - Disclosure - Investments - Additional Information (Detail) Network

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*

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1550 Disclosure of detailed information about investment property [table] Table

*

*

 ifrs-full:DisclosureOfInvestmentPropertyTable
1551 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
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1554 Santo Antonio Hydroelectric Plant Through Madeira Energia SA (Mesa) and FIP Melbourne [member] Member xcmig:SantoAntonioHydroelectricPlantThroughMadeiraEnergiaSaMesaAndFipMelbourneMember
1555 SAAG Investimentos S.A. and Ceming GT [Member] Member xcmig:SAAGInvestimentosSAAndCemingGTMember
1556 Cemig GT [member] Member xcmig:CemigGTMember
1557 Renova Energia SA [member] Member xcmig:RenovaEnergiaSAMember
1558 Terra Form Global Inc [Member] Member xcmig:TerraFormGlobalIncMember
1559 Renova [member] Member xcmig:RenovaMember
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1563 BrasilPCHSA [member] Member xcmig:BrasilpchsaMember
1564 Lepsa [member] Member xcmig:LepsaMember
1565 RME [member] Member xcmig:RmeMember
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1567 Entity's total for business combinations [member] Member ifrs-full:EntitysTotalForBusinessCombinationsMember
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1569 Madeira Energia [member] Member xcmig:MadeiraEnergiaMember
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1584 Investments in jointly controlled entities and affiliated companies Concept (Monetary) As Of Debit ifrs-full:InvestmentsInSubsidiariesJointVenturesAndAssociates
1585 Expenditures on property plant and equipment Concept (Monetary) For Period Debit xcmig:ExpendituresOnPropertyPlantAndEquipment
1586 Payments for claims Concept (Monetary) For Period Debit xcmig:PaymentsForClaims
1587 Adjustments for impairment Concept (Monetary) For Period Debit xcmig:AdjustmentsForImpairment
1588 InvestmentWriteDowns Concept (Monetary) For Period Credit ifrs-full:ReversalOfImpairmentLossRecognisedInProfitOrLoss
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1593 Reclassified positive adjustments in other comprehensive income Concept (Monetary) For Period Debit ifrs-full:ReclassificationAdjustmentsOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeNetOfTax
1594 Arbitration proceedings Concept (Monetary) As Of Debit xcmig:ArbitrationProceedingsClaims
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1596 Proceeds from sales of plant Concept (Monetary) For Period Debit ifrs-full:ProceedsFromSalesOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities
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1598 Earn out payments Concept (Monetary) For Period Debit xcmig:EarnOutPayments
1599 Projects development Concept (Monetary) As Of Debit xcmig:ProjectsUnderDevelopment
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1607 1121 - Disclosure - Investments - Summarized Financial Information of the Company's Equity Investees (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureInvestmentsSummarizedFinancialInformationOfTheCompanysEquityInvestees
1608 Disclosure of detailed information about investment property [table] Table

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*

 ifrs-full:DisclosureOfInvestmentPropertyTable
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1612 Transleste [member] Member xcmig:TranslesteMember
1613 Transirape [member] Member xcmig:TransirapeMember
1614 Centroeste [member] Member xcmig:CentroesteMember
1615 Transudeste [member] Member xcmig:TransudesteMember
1616 Luce [member] Member xcmig:LuceMember
1617 Rio Minas Energia Participacoes SA [member] Member xcmig:RioMinasEnergiaParticipacoesSAMember
1618 Light SA [member] Member xcmig:LightSAMember
1619 Transmissora Alianca de Energia Eletrica S.A. [member] Member xcmig:TransmissoraAliancadeEnergiaEletricaSAMember
1620 Axxiom [member] Member xcmig:AxxiomMember
1621 Alianca Norte Energia Participacoes S A [member] Member xcmig:AliancaNorteEnergiaParticipacoesSAMember
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1624 Taesa [member] Member xcmig:TaesaMember
1625 Itaocara hydroelectric plant [Member] Member xcmig:ItaocaraHydroelectricPlantMember
1626 Lightger [member] Member xcmig:LightGerMember
1627 Amazonia Energia [member] Member xcmig:AmazoniaEnergiaMember
1628 Alianca Geracao [member] Member xcmig:AliancaGeracaoMember
1629 Hidreletrica Cachoeirao [member] Member xcmig:HidreletricaCachoeiraoMember
1630 Baguari Energia [member] Member xcmig:BaguariEnergiaMember
1631 Guanhaes energia [member] Member xcmig:GuanhaesEnergiaMember
1632 Madeira Energia [member] Member xcmig:MadeiraEnergiaMember
1633 Pipoca [member] Member xcmig:PipocaMember
1634 Retiro Baixo [member] Member xcmig:RetiroBaixoMember
1635 Renova [member] Member xcmig:RenovaMember
1636 Parajuru [Member] Member xcmig:ParajuruMember
1637 Morgado [Member] Member xcmig:MorgadoMember
1638 Voltado Rio [Member] Member xcmig:VoltadoRioMember
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1640 Transchile Charrua Transmision SA [Member] Member xcmig:TranschileMember
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1646 Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
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1662 Net Finance income (expenses) Concept (Monetary) For Period Credit ifrs-full:FinanceIncomeCost
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1664 Impairment of PP&E Concept (Monetary) For Period ifrs-full:ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipment
1665 Finance income Concept (Monetary) For Period Credit ifrs-full:FinanceIncome
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1667 Income before income tax and social contribution tax Concept (Monetary) For Period Credit ifrs-full:ProfitLossBeforeTax
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1670 Comprehensive income (loss) effects Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncome
1671 Comprehensive income (loss) for the year Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncome
1672 1122 - Disclosure - Investments - Disclosure Of Fair Value Of The Assets Acquired Resulted In Fair Value (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureInvestmentsDisclosureOfFairValueOfTheAssetsAcquiredResultedInFairValue
1673 Disclosure of detailed information about business combination [table] Table

*

*

 ifrs-full:DisclosureOfBusinessCombinationsTable
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1681 Fair value, equity Concept (Monetary) As Of Credit ifrs-full:NoncontrollingInterestInAcquireeRecognisedAtAcquisitionDate
1682 Total Concept (Monetary) As Of Debit ifrs-full:IdentifiableAssetsAcquiredLiabilitiesAssumed
1683 1123 - Disclosure - Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosurePropertyPlantAndEquipmentScheduleOfPropertyPlantAndEquipment
1684 Disclosure of detailed information about property, plant and equipment [table] Table

*

*

 ifrs-full:DisclosureOfPropertyPlantAndEquipmentTable
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1687 Gross Carrying Amount [member] Member ifrs-full:GrossCarryingAmountMember
1688 Accumulated Depreciation and Amortisation [member] Member ifrs-full:AccumulatedDepreciationAndAmortisationMember
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1691 Investment Property Completed [member] Member ifrs-full:InvestmentPropertyCompletedMember
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1697 Buildings Works And Improvements [member] Member xcmig:BuildingsWorksAndImprovementsMember
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1703 1124 - Disclosure - Property, Plant and Equipment - Summary of Movement in Property, Plant and Equipment (Detail) Network

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 http://imetrix.edgar-online.com/taxonomy/role/DisclosurePropertyPlantAndEquipmentSummaryOfMovementInPropertyPlantAndEquipment
1704 Disclosure of detailed information about property, plant and equipment [table] Table

*

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 ifrs-full:DisclosureOfPropertyPlantAndEquipmentTable
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1713 Buildings Works And Improvements [member] Member xcmig:BuildingsWorksAndImprovementsMember
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1720 Jaguara, Miranda and Volta Grande Plants Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughTransfersFromConstructionInProgressPropertyPlantAndEquipment
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1722 Transfer of assets to Alianca Geracao de Energia Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughTransfersFromToInvestmentPropertyPropertyPlantAndEquipment
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1725 Transfers to other long term assets Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughOtherChangesPropertyPlantAndEquipment
1726 Transfers / capitalizations Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughTransfersPropertyPlantAndEquipment
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1728 1125 - Disclosure - Property, Plant and Equipment - Additional Information (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosurePropertyPlantAndEquipmentAdditionalInformation
1729 Implied Table Table

*

*

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1732 1126 - Disclosure - Property, Plant and Equipment - Summary of Accumulated Investments in Consortium (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosurePropertyPlantAndEquipmentSummaryOfAccumulatedInvestmentsInConsortium
1733 Disclosure of detailed information about property, plant and equipment [table] Table

*

*

 ifrs-full:DisclosureOfPropertyPlantAndEquipmentTable
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1754 1127 - Disclosure - Intangible Assets - Summary of Composition of Intangible Assets (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureIntangibleAssetsSummaryOfCompositionOfIntangibleAssets
1755 Disclosure of detailed information about intangible assets [table] Table

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1770 1128 - Disclosure - Intangible Assets - Summary of Changes in Intangible Assets (Detail) Network

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 http://imetrix.edgar-online.com/taxonomy/role/DisclosureIntangibleAssetsSummaryOfChangesInIntangibleAssets
1771 Disclosure of detailed information about intangible assets [table] Table

*

*

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1792 1129 - Disclosure - Intangible Assets - Summary of Changes in Intangible Assets (Parenthetical) (Detail) Network

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1793 Disclosure of detailed information about intangible assets [table] Table

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 ifrs-full:DisclosureOfIntangibleAssetsTable
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1802 1130 - Disclosure - Intangible Assets - Additional Information (Detail) Network

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1803 Disclosure of detailed information about intangible assets [table] Table

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1813 1131 - Disclosure - Suppliers - Summary of Suppliers (Detail) Network

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1814 Disclosure of trade payables [Table] Table

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1825 1132 - Disclosure - Taxes, Income Tax and Social Contribution - Summary of Tax Payable (Detail) Network

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1843 1133 - Disclosure - Taxes, Income Tax and Social Contribution - Additional Information (Detail) Network

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1844 Disclosure of taxes payable [table] Table

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1859 Selic rate Concept (Percent) For Period xcmig:SelicRate
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1861 Installments settlement unpaid Concept (Monetary) For Period Debit xcmig:TaxSettlementAmountPayable
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1863 Write down tax expense Concept (Monetary) For Period Debit xcmig:WrotedownOtherIncomeAndExpenses
1864 Escrow deposits Concept (Monetary) As Of Debit xcmig:AmountInEscrowDeposits
1865 Taxes on revenues Concept (Monetary) For Period Debit xcmig:TaxesOnRevenues
1866 1134 - Disclosure - Taxes, Income Tax and Social Contribution - Summary of Income Tax and Social Contribution Tax (Detail) Network

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1867 Implied Table Table

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1871 Total income and social contribution tax Concept (Monetary) As Of Credit xcmig:CurrentPayablesOnSocialSecurityAndTaxes
1872 1135 - Disclosure - Loans, Financings and Debentures - Summary of Loans Financing and Debentures (Detail) Network

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1873 Disclosure of detailed information about borrowings [table] Table

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1881 Eurobonds [member] Member xcmig:EurobondsMember
1882 Banco do Brasil (Cemig GT) [member] Member xcmig:BancoDoBrasilMember
1883 CEF [member] Member xcmig:CEFMember
1884 Eletrobras [member] Member xcmig:EletrobrasMember
1885 Large Consumers [member] Member xcmig:LargeConsumersMember
1886 FINEP [member] Member xcmig:FINEPMember
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1888 Banco da amazonia [member] Member xcmig:BancoDaAmazoniaMember
1889 Sonda (Cemig Telecom) [member] Member xcmig:SondaMember
1890 Transaction costs [member] Member xcmig:TransactionCostsMember
1891 Debentures-3rd Issue, 1st Series [member] Member xcmig:DebenturesThirdIssueFirstSeriesMember
1892 Debentures-3rd Issue, 2nd Series [member] Member xcmig:DebenturesThirdIssueSecondSeriesMember
1893 Debentures-3rd Issue, 3rd Series [member] Member xcmig:DebenturesThirdIssueThirdSeriesMember
1894 Debentures-5th Issue, 1st Series [member] Member xcmig:DebenturesFifthIssueFirstSeriesMember
1895 Debentures sixth issue first series [member] Member xcmig:DebenturesSixthIssueFirstSeriesMember
1896 Debentures-7th Issue, 1st Series [member] Member xcmig:DebenturesSeventhIssueFirstSeriesMember
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1898 Debentures fourth issue first series [member] Member xcmig:DebenturesFourthIssueFirstSeriesMember
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1900 Subsidiary Securities [member] Member xcmig:SubsidiarySecuritiesMember
1901 Net debentures [member] Member xcmig:NetDebenturesMember
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1912 TJLP Plus Two Point Three Four [member] Member xcmig:TJLPPlusTwoPointThreeFourMember
1913 One One Nine Point Zero Zero Percent of interbank rate for certificates of deposit [member] Member xcmig:OneOneNinePointZeroZeroPercentOfInterbankRateForCertificatesOfDepositMember
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1917 One one zero percent of interbank rate for certificates of deposit [member] Member xcmig:OneOneZeroPercentOfInterbankRateForCertificatesOfDepositMember
1918 Debt in Brazilian currency [member] Member xcmig:DebtInBrazilianCurrencyMember
1919 Loans and Financings [member] Member xcmig:LoansAndFinancingsMember
1920 Interbank rate for certificates of deposit plus zero point nine zero [member] Member xcmig:InterbankRateForCertificatesOfDepositPlusZeroPointNineZeroMember
1921 Ipca plus six point zero zero [member] Member xcmig:IPCAPlusSixPointZeroZeroMember
1922 Ipca plus six point two zero [member] Member xcmig:IPCAPlusSixPointTwoZeroMember
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1929 Ipca plus five point one zero [member] Member xcmig:IPCAPlusFivePointOneZeroMember
1930 Interbank rate for certificates of deposit plus four point zero five percentage one [member] Member xcmig:InterbankRateForCertificatesOfDepositPlusFourPointZeroFivePercentageOneMember
1931 CDI + 1.60 [member] Member xcmig:InterbankRateForCertificatesOfDepositPlusOnePointSixZeroPercentageOneMember
1932 Interbank rate for certificates of deposit plus zero point seven four [member] Member xcmig:InterbankRateForCertificatesOfDepositPlusZeroPointSevenFourMember
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1934 One one six point five zero percent of inter bank rate for certificates of deposit [member] Member xcmig:OneOneSixPointFiveZeroPercentOfInterBankRateForCertificatesOfDepositMember
1935 One two eight point five zero percent of inter bank rate for certificates of deposit [member] Member xcmig:OneTwoEightPointFiveZeroPercentOfInterBankRateForCertificatesOfDepositMember
1936 Transaction costs [member] Member xcmig:TransactionCostsMember
1937 Disclosure of detailed information about borrowings [line items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
1938 Principal maturity Concept (Text/String) For Period ifrs-full:BorrowingsMaturity
1939 Annual financial cost Concept (Text/String) For Period xcmig:DescriptionOfLoansFinancingsAndDebenturesAnnualFinancingCost
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1942 Current Concept (Monetary) As Of Credit ifrs-full:CurrentLoansReceivedAndCurrentPortionOfNoncurrentLoansReceived
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1947 Total Concept (Monetary) As Of Credit ifrs-full:NotesAndDebenturesIssued
1948 Total Concept (Monetary) As Of Credit ifrs-full:LoansReceived
1949 Total Concept (Monetary) As Of Credit ifrs-full:Borrowings
1950 1136 - Disclosure - Loans, Financings and Debentures - Summary of Loans Financing and Debentures (Parenthetical) (Detail) Network

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1951 Disclosure of detailed information about borrowings [table] Table

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1967 Libor plus spreadrate Concept (Percent) For Period xcmig:LiborPlusSpreadRate
1968 1137 - Disclosure - Loans, Financings and Debentures - Summary of Guarantees of the Debtor Balance on Loans and Financings (Detail) Network

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1969 Disclosure of detailed information about borrowings [table] Table

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1981 1138 - Disclosure - Loans, Financings and Debentures - Summary Consolidated Composition of Loans, Financings and Debentures, by Currency and Indexor, with the Respective Amortization (Detail) Network

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1982 Disclosure of detailed information about borrowings [table] Table

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1987 2020 [member] Member ifrs-full:LaterThanTwoYearsAndNotLaterThanThreeYearsMember
1988 2021 [member] Member ifrs-full:LaterThanThreeYearsAndNotLaterThanFourYearsMember
1989 2022 [member] Member ifrs-full:LaterThanFourYearsAndNotLaterThanFiveYearsMember
1990 2023 [member] Member xcmig:LaterThanFiveYearsAndNotLaterThanSixYearsMember
1991 2024 [member] Member xcmig:LaterThanSixYearsAndNotLaterThanSevenYearsMember
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2010 1139 - Disclosure - Loans, Financings and Debentures - Summary of the Currencies and Indexors Used for Monetary Updating of Loans and Financings (Detail) Network

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2011 Disclosure of detailed information about borrowings [table] Table

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2019 Euro [member] Member currency:EUR
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2023 1140 - Disclosure - Loans, Financings and Debentures - Summary of Changes in Loans, Financings and Debentures (Detail) Network

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2045 1141 - Disclosure - Loans, Financings and Debentures - Summary of Changes in Loans, Financings and Debentures (Parenthetical) (Detail) Network

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2046 Implied Table Table

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2049 1142 - Disclosure - Loans, Financings and Debentures - Transferred to Intangible Assets the Costs of Loans and Financings Linked to Working in Progress (Detail) Network

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2050 Implied Table Table

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2055 1143 - Disclosure - Loans, Financings and Debentures - Consolidated Totals of Funds Raised (Detail) Network

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2056 Disclosure of detailed information about borrowings [table] Table

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2077 Eurobonds [member] Member xcmig:EurobondsMember
2078 Debentures, 2nd Issue [member] Member xcmig:DebenturesSecondIssueMember
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2080 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
2081 Debt in Brazilian currency [member] Member xcmig:DebtInBrazilianCurrencyMember
2082 Debt in Foreign Currency [member] Member xcmig:DebtInForeignCurrencyMember
2083 Types of interest rates [axis] Axis ifrs-full:TypesOfInterestRatesAxis
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2085 Floating rates [member] Member ifrs-full:FloatingInterestRateMember
2086 Fixed rate [member] Member ifrs-full:FixedInterestRateMember
2087 Types of financial liabilities [axis] Axis ifrs-full:TypesOfFinancialLiabilitiesAxis
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2090 Selic [member] Member xcmig:SelicMember
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2095 Transaction costs Concept (Monetary) For Period Debit ifrs-full:BorrowingCostsRecognisedAsExpense
2096 Interest paid in advance Concept (Monetary) For Period Credit ifrs-full:InterestIncomeOnLoansAndAdvancesToBanks
2097 1144 - Disclosure - Loans, Financings and Debentures - Consolidated Totals of Funds Raised (Parenthetical) (Detail) Network

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2098 Disclosure of detailed information about borrowings [table] Table

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2099 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
2100 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
2101 Cemig Telecom [member] Member xcmig:CemigTelecomMember
2102 Disclosure of detailed information about borrowings [line items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
2103 Taxes with no cash effect Concept (Monetary) For Period Credit xcmig:TaxesWithNoCashEffect
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2105 Annual remuneration percentage Concept (Percent) For Period xcmig:AnnualRemunerationPercentage
2106 Non-convertible debentures amortisation period Concept (xbrli:durationItemType) For Period xcmig:NonconvertibleDebenturesAmortisationPeriod
2107 1145 - Disclosure - Loans, Financings and Debentures - Additional Information (Detail) Network

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2108 Disclosure of detailed information about borrowings [table] Table

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2109 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
2110 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
2111 Eurobonds [member] Member xcmig:EurobondsMember
2112 Disclosure of detailed information about borrowings [line items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
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2116 Percentage of hedge transaction cost Concept (Percent) For Period xcmig:PercentageOfHedgeTransactionCost
2117 1146 - Disclosure - Loans, Financings and Debentures - Characteristics of Nonconvertible Debentures Issued by Company (Detail) Network

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2118 Disclosure of detailed information about borrowings [table] Table

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2119 Types of financial liabilities [axis] Axis ifrs-full:TypesOfFinancialLiabilitiesAxis
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2122 Selic [member] Member xcmig:SelicMember
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2126 Cemig GT third issue second series [member] Member xcmig:CemigGTThirdIssueSecondSeriesMember
2127 Cemig GT third issue third series [member] Member xcmig:CemigGTThirdIssueThirdSeriesMember
2128 Cemig GT fifth issue first series [member] Member xcmig:CemigGTFifthIssueFirstSeriesMember
2129 Cemig GT - 6th Issue - 1st Series [member] Member xcmig:CemigGtSixthIssueFirstSeriesMember
2130 Cemig GT - 6th Issue - 2nd Series [member] Member xcmig:CemigGtSixthIssueSecondSeriesMember
2131 Cemig GT - 7th Issue - 1st Series [member] Member xcmig:CemigGtSeventhIssueFirstSeriesMember
2132 Cemig D second issue [Member] Member xcmig:CemigDSecondIssueMember
2133 Cemig D - 3rd Issue - 1st Series [member] Member xcmig:CemigDThirdIssueFirstSeriesMember
2134 Cemig D - 3rd Issue - 2nd Series [member] Member xcmig:CemigDThirdIssueSecondSeriesMember
2135 Cemig D - 3rd Issue - 3rd Series [member] Member xcmig:CemigDThirdIssueThirdSeriesMember
2136 Cemig D forth issue single series [member] Member xcmig:CemigDForthIssueSingleSeriesMember
2137 Cemig D fifth issue single series [member] Member xcmig:CemigDFifthIssueSingleSeriesMember
2138 Gasmig [member] Member xcmig:GasmigMember
2139 Cemig Telecom [member] Member xcmig:CemigTelecomMember
2140 Subsidiary Securities [member] Member xcmig:SubsidiarySecuritiesMember
2141 Transaction costs [member] Member xcmig:TransactionCostsMember
2142 Debentures [member] Member xcmig:DebenturesMember
2143 Continuing involvement in derecognised financial assets by type of instrument [axis] Axis ifrs-full:ContinuingInvolvementInDerecognisedFinancialAssetsByTypeOfInstrumentAxis
2144 Types of instrument [member] Member ifrs-full:TypesOfInstrumentMember
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2146 Surety guarantee [member] Member xcmig:SuretyGuaranteeMember
2147 Receivables revenue guarantee [member] Member xcmig:ReceivablesRevenueGuaranteeMember
2148 No guarantee [member] Member xcmig:NoGuaranteeMember
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2153 Interbank rate for certificates of deposit plus zero point nine zero percentage [member] Member xcmig:InterbankRateForCertificatesOfDepositPlusZeroPointNineZeroPercentageMember
2154 Expanded national consumer price index plus six point zero percentage [member] Member xcmig:ExpandedNationalConsumerPriceIndexPlusSixPointZeroPercentageMember
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2161 Interbank rate for certificates of deposit plus zero point six nine percentage [member] Member xcmig:InterbankRateForCertificatesOfDepositPlusZeroPointSixNinePercentageMember
2162 Expanded national consumer price index plus four point seven zero percentage [member] Member xcmig:ExpandedNationalConsumerPriceIndexPlusFourPointSevenZeroPercentageMember
2163 Expanded national consumer price index plus five point one zero percentage [member] Member xcmig:ExpandedNationalConsumerPriceIndexPlusFivePointOneZeroPercentageMember
2164 Interbank rate for certificates of deposit plus four point zero five percentage [member] Member xcmig:InterbankRateForCertificatesOfDepositPlusFourPointZeroFivePercentageMember
2165 One four six point five zero percentage of interbank rate for certificates of deposit [member] Member xcmig:OneFourSixPointFiveZeroPercentageOfInterbankRateForCertificatesOfDepositMember
2166 Interbank rate for certificates of deposit plus zero point seven four [member] Member xcmig:InterbankRateForCertificatesOfDepositPlusZeroPointSevenFourMember
2167 TJLP plus one point eight two and selic plus one point eight two percentage [member] Member xcmig:TJLPPlusOnePointEightTwoAndSelicPlusOnePointEightTwoPercentageMember
2168 One two eight point five zero percentage of interbank rate for certificates of deposit [member] Member xcmig:OneTwoEightPointFiveZeroPercentageOfInterbankRateForCertificatesOfDepositMember
2169 Disclosure of detailed information about borrowings [line items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
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2173 2016 Concept (Monetary) As Of Credit ifrs-full:Borrowings
2174 1147 - Disclosure - Loans, Financings and Debentures - Summary of Contracts With Covenants Linked to Financial Index (Detail) Network

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2175 Disclosure of contracts with covenants linked to financial indices [Table] Table

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2179 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
2180 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
2181 Net debt/ (Ebitda plus Dividends received) [member] Member xcmig:NetDebtEbitdaPlusDividendsReceivedMember
2182 Net debt/ Ebitda adjusted for the Covenant [member] Member xcmig:NetDebtEbitdaAdjustedForTheCovenantMember
2183 Current liquidity [member] Member xcmig:CurrentLiquidityMember
2184 Overall indebtedness (Total liabilities/Total assets) [member] Member xcmig:OverallIndebtednessTotalLiabilitiesTotalAssetsMember
2185 Ebitda / Debt servicing [member] Member xcmig:EbitdaDebtServicingMember
2186 Ebitda / Net finance income (expenses) [member] Member xcmig:EbitdaNetFinancialRevenueExpensesMember
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2195 Maturity on December thirty one two thousand eighteen [member] Member xcmig:MaturityOnDecemberThirtyOneTwoThousandEighteenMember
2196 Maturity on June thirty two thousand nineteen [member] Member xcmig:MaturityOnJuneThirtyTwoThousandNineteenMember
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2199 Maturity on December thirty one two thousand twenty [member] Member xcmig:MaturityOnDecemberThirtyOneTwoThousandTwentyMember
2200 Maturity on June thirty two thousand twenty one [member] Member xcmig:MaturityOnJuneThirtyTwoThousandTwentyOneMember
2201 Maturity on December thirty one two thousand twenty one [member] Member xcmig:MaturityOnDecemberThirtyOneTwoThousandTwentyOneMember
2202 2018 [member] Member ifrs-full:NotLaterThanOneYearMember
2203 Later than one year [member] Member ifrs-full:LaterThanOneYearMember
2204 2020 [member] Member ifrs-full:LaterThanTwoYearsAndNotLaterThanThreeYearsMember
2205 2021 [member] Member ifrs-full:LaterThanThreeYearsAndNotLaterThanFourYearsMember
2206 2022 [member] Member ifrs-full:LaterThanFourYearsAndNotLaterThanFiveYearsMember
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2209 Maturity on December thirty one two thousand eighteen 3 [member] Member xcmig:MaturityOnDecemberThirtyOneTwoThousandEighteen3Member
2210 Maturity on June thirty two thousand nineteen2 [member] Member xcmig:MaturityOnJuneThirtyTwoThousandNineteen2Member
2211 Maturity on December thirty one two thousand nineteen 2 [member] Member xcmig:MaturityOnDecemberThirtyOneTwoThousandNineteen2Member
2212 Maturity on June thirty two thousand twenty3 [member] Member xcmig:MaturityOnJuneThirtyTwoThousandTwenty3Member
2213 Maturity on December thirty one two thousand twenty2 [member] Member xcmig:MaturityOnDecemberThirtyOneTwoThousandTwenty2Member
2214 Maturity on December thirty one two thousand seventeen 1[member] Member xcmig:MaturityOnDecemberThirtyOneTwoThousandSeventeen1Member
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2216 Maturity on December thirty one two thousand eighteen2 [member] Member xcmig:MaturityOnDecemberThirtyOneTwoThousandEighteen2Member
2217 Maturity on June thirty two thousand nineteen3 [member] Member xcmig:MaturityOnJuneThirtyTwoThousandNineteen3Member
2218 Maturity on December thirty one two thousand nineteen 3 [member] Member xcmig:MaturityOnDecemberThirtyOneTwoThousandNineteen3Member
2219 Maturity on June thirty two thousand twenty2 [member] Member xcmig:MaturityOnJuneThirtyTwoThousandTwenty2Member
2220 Maturity on December thirty one two thousand twenty3 [member] Member xcmig:MaturityOnDecemberThirtyOneTwoThousandTwenty3Member
2221 Maturity on June thirty two thousand twenty one2 [member] Member xcmig:MaturityOnJuneThirtyTwoThousandTwentyOne2Member
2222 Disclosure of contracts with covenants linked to financial indices [Line Items] LineItems xcmig:DisclosureOfContractsWithCovenantsLinkedToFinancialIndicesLineItems
2223 Transaction Concept (Text/String) For Period xcmig:FinancialIndicesTransactionDescription
2224 Ratio Concept (Text/String) For Period xcmig:FinancialIndicesTransactionRatioDescription
2225 Ratio requirement - Issuer Concept (Percent) For Period xcmig:FinancialIndicesRatioRequirementIssuerPercentage
2226 Ratio requirement - Cemig (Guarantor) Concept (Percent) For Period xcmig:FinancialIndicesRatioRequirementGuarantorPercentage
2227 Timing requirement Concept (Text/String) For Period xcmig:FinancialIndicesTimingRequirementDescription
2228 1148 - Disclosure - Loans, Financings and Debentures - Summary of Contracts With Covenants Linked to Financial Index (Parenthetical) (Detail) Network

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2229 Disclosure of contracts with covenants linked to financial indices [Table] Table

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2230 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
2231 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
2232 Cemig GT [member] Member xcmig:CemigGTMember
2233 Gasmig [member] Member xcmig:GasmigMember
2234 Disclosure of contracts with covenants linked to financial indices [Line Items] LineItems xcmig:DisclosureOfContractsWithCovenantsLinkedToFinancialIndicesLineItems
2235 Debentures Concept (Monetary) As Of Credit xcmig:Debentures
2236 Description of communication duration to debenture holders Concept (Text/String) For Period xcmig:DescriptionOfCommunicationDurationToDebentureHolders
2237 1149 - Disclosure - Regulatory Charges - Disclosure of Information About Amounts Recognised in Relation to Regulatory Deferral Account Balances (Detail) Network

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2238 Disclosure of information about amounts recognised in relation to regulatory deferral account balances [table] Table

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2239 Types of rate-regulated activities [axis] Axis ifrs-full:TypesOfRateregulatedActivitiesAxis
2240 Rate-regulated activities [member] Member ifrs-full:RateregulatedActivitiesMember
2241 Regulatory Assets [member] Member xcmig:RegulatoryAssetsMember
2242 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
2243 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
2244 Receivable from Eletrobras - RGR [member] Member xcmig:EletrobrasGlobalReversionReserveMember
2245 Receivable from Eletrobras - CDE [member] Member xcmig:EletrobrasEnergyDevelopmentAccountMember
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2247 Assets Abstract ifrs-full:AssetsAbstract
2248 Receivable from Eletrobras Concept (Monetary) As Of Debit ifrs-full:NoncurrentReceivablesDueFromRelatedParties
2249 Liabilities Abstract ifrs-full:RegulatoryDeferralAccountCreditBalancesAndRelatedDeferredTaxLiabilityAbstract
2250 Global Reversion Reserve (RGR) Concept (Monetary) As Of Debit xcmig:GlobalReversionReserve
2251 Energy Development Account (CDE) Concept (Monetary) As Of Credit xcmig:EnergyDevelopmentAccount
2252 Aneel inspection charge Concept (Monetary) As Of Credit xcmig:AneelInspectionCharge
2253 Energy Efficiency Concept (Monetary) As Of Credit xcmig:EnergyEfficiency
2254 Research and development Concept (Monetary) For Period Debit ifrs-full:ResearchAndDevelopmentExpense
2255 Energy System Expansion Research Concept (Monetary) As Of Credit xcmig:EnergySystemExpansionResearch
2256 National Scientific and Technological Development Fund Concept (Monetary) As Of Credit xcmig:NationalScientificAndTechnologicalDevelopmentFund
2257 Proinfa - Alternative Energy Program Concept (Monetary) As Of Credit xcmig:ProinfaAlternativeEnergyProgram
2258 Royalties for use of water resources Concept (Monetary) For Period Debit xcmig:RoyaltiesForUseOfWaterResources
2259 Emergency capacity charge Concept (Monetary) As Of Credit xcmig:EmergencyCapacityCharge
2260 Customer charges - 'Tariff Flag' amounts Concept (Monetary) As Of Debit ifrs-full:ConsumerLoans
2261 Liability Concept (Monetary) As Of Credit ifrs-full:RegulatoryDeferralAccountCreditBalancesAndRelatedDeferredTaxLiability
2262 Current liabilities Concept (Monetary) As Of Credit xcmig:CurrentRegulatoryLiability
2263 Non-current liabilities Concept (Monetary) As Of Credit xcmig:NoncurrentRegulatoryLiability
2264 1150 - Disclosure - Post-Retirement Liabilities - Additional Information (Detail) Network

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2265 Disclosure of defined benefit plans [table] Table

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2266 Types of contracts [axis] Axis ifrs-full:TypesOfContractsAxis
2267 Types of contracts [member] Member ifrs-full:TypesOfContractsMember
2268 Forluz pension [member] Member xcmig:ForluzPensionMember
2269 Non-adjusting events after reporting period [axis] Axis ifrs-full:NonadjustingEventsAfterReportingPeriodAxis
2270 Non-adjusting events after reporting period [member] Member ifrs-full:NonadjustingEventsMember
2271 Entering into significant commitments or contingent liabilities [member] Member ifrs-full:EnteringIntoSignificantCommitmentsOrContingentLiabilitiesMember
2272 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
2273 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
2274 Post Employment Benefit Obligations [Member] Member xcmig:PostEmploymentBenefitObligationsMember
2275 Pension Funds [member] Member xcmig:PensionFundsMember
2276 Defined contribution plan [member] Member xcmig:DefinedContributionPlanMember
2277 Disclosure of defined benefit plans [line items] LineItems ifrs-full:DisclosureOfDefinedBenefitPlansLineItems
2278 Obligation for past actuarial deficits relating to pension fund Concept (Monetary) As Of Credit ifrs-full:ActuarialPresentValueOfPromisedRetirementBenefits
2279 Obligation for past actuarial deficits amortization description Concept (Text/String) For Period xcmig:ObligationForPastActuarialDeficitsAmortizationDescription
2280 Obligation rate for actuarial assumption Concept (Percent) As Of xcmig:ObligationRate
2281 Retirement benefits plan Concept (Monetary) For Period Debit ifrs-full:BenefitsPaidOrPayable
2282 Remuneratory interest Concept (Percent) As Of xcmig:BorrowingsRemuneratoryPayInterestRate
2283 deficit found in Plan Concept (Monetary) As Of Credit xcmig:DeficitSurplusOfDefinedBenefitPensionPlan
2284 Monthly installments Concept (Text/String) For Period xcmig:DescriptionOfInstallments
2285 Costs of post-employment obligations Concept (Monetary) For Period Debit ifrs-full:PostemploymentBenefitExpenseDefinedContributionPlans
2286 Financial costs and monetary updating expence Concept (Monetary) For Period Debit xcmig:FinancialExpenses
2287 Life insurance, a recovery of expense Concept (Monetary) For Period Credit xcmig:InsuranceRecoveryOfLitigationExpenses
2288 Expected employer contributions Concept (Monetary) As Of Credit xcmig:ExpectedContributionsToPlanByEmployerInNextTwelveMonths
2289 1151 - Disclosure - Post-Retirement Obligation - Disclosure Of Consolidated Actuarial Information (Detail) Network

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2290 Disclosure of defined benefit plans [table] Table

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2291 Actuarial assumptions [axis] Axis ifrs-full:ActuarialAssumptionsAxis
2292 Actuarial assumptions [member] Member ifrs-full:ActuarialAssumptionsMember
2293 Actuarial assumptions [Member] Member ifrs-full:ActuarialAssumptionOfExpectedRatesOfPensionIncreasesMember
2294 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
2295 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
2296 Pension plans and retirement supplement plans [member] Member xcmig:PensionPlansAndRetirementSupplementPlansMember
2297 Health plan [member] Member xcmig:HealthPlanMember
2298 Dental plan [member] Member xcmig:DentalPlanMember
2299 Life insurance [member] Member xcmig:LifeInsuranceMember
2300 Net defined benefit liability (asset) [axis] Axis ifrs-full:NetDefinedBenefitLiabilityAssetAxis
2301 Net defined benefit liability (asset) [member] Member ifrs-full:NetDefinedBenefitLiabilityAssetMember
2302 Initial net liabilities [member] Member xcmig:InitialNetLiabilitiesMember
2303 Adjustment to asset ceiling [member] Member ifrs-full:EffectOfAssetCeilingMember
2304 Disclosure of defined benefit plans [line items] LineItems ifrs-full:DisclosureOfDefinedBenefitPlansLineItems
2305 Present value of funded obligations Concept (Monetary) As Of Credit ifrs-full:DefinedBenefitObligationAtPresentValue
2306 Fair value of plan assets Concept (Monetary) As Of Debit ifrs-full:PlanAssetsAtFairValue
2307 Net liabilities in the statement of financial position Concept (Monetary) As Of Debit ifrs-full:SurplusDeficitInPlan
2308 1152 - Disclosure - Post-Retirement Obligation - Disclosure of Changes In Present Value of Defined Benefit Obligation (Detail) Network

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2309 Disclosure of net defined benefit liability (asset) [table] Table

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2310 Net defined benefit liability (asset) [axis] Axis ifrs-full:NetDefinedBenefitLiabilityAssetAxis
2311 Net defined benefit liability (asset) [member] Member ifrs-full:NetDefinedBenefitLiabilityAssetMember
2312 Present value of defined benefit obligation [member] Member ifrs-full:PresentValueOfDefinedBenefitObligationMember
2313 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
2314 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
2315 Pension plans and retirement supplement plans [member] Member xcmig:PensionPlansAndRetirementSupplementPlansMember
2316 Health plan [member] Member xcmig:HealthPlanMember
2317 Dental plan [member] Member xcmig:DentalPlanMember
2318 Life insurance [member] Member xcmig:LifeInsuranceMember
2319 Disclosure of net defined benefit liability (asset) [line items] LineItems ifrs-full:DisclosureOfNetDefinedBenefitLiabilityAssetLineItems
2320 Beginning balance Concept (Monetary) As Of Credit ifrs-full:LiabilityAssetOfDefinedBenefitPlans
2321 Cost of current service Concept (Monetary) For Period Credit ifrs-full:CurrentServiceCostNetDefinedBenefitLiabilityAsset
2322 Interest on the actuarial obligation Concept (Monetary) For Period Credit ifrs-full:InterestExpenseIncomeNetDefinedBenefitLiabilityAsset
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2324 Cost of current service Concept (Monetary) For Period Credit ifrs-full:CurrentServiceCostNetDefinedBenefitLiabilityAsset
2325 Interest on the actuarial obligation Concept (Monetary) For Period Credit ifrs-full:InterestExpenseIncomeNetDefinedBenefitLiabilityAsset
2326 Due to changes in demographic assumptions Concept (Monetary) For Period Debit ifrs-full:ActuarialGainsLossesArisingFromChangesInDemographicAssumptionsNetDefinedBenefitLiabilityAsset
2327 Due to changes in financial assumptions Concept (Monetary) For Period Debit ifrs-full:ActuarialGainsLossesArisingFromChangesInFinancialAssumptionsNetDefinedBenefitLiabilityAsset
2328 Due to adjustments based on experience Concept (Monetary) For Period Debit xcmig:ActuarialGainsLossesArisingFromAdjustmentsBasedOnExperienceNetDefinedBenefitLiabilityAsset
2329 Due to changes and adjustments Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseInNetDefinedBenefitLiabilityAsset
2330 Plan amendment - Past service Concept (Monetary) For Period Debit ifrs-full:GainsLossesArisingFromSettlementsNetDefinedBenefitLiabilityAsset
2331 Benefits paid Concept (Monetary) For Period Debit ifrs-full:PaymentsFromPlanNetDefinedBenefitLiabilityAsset
2332 Ending balance Concept (Monetary) As Of Credit ifrs-full:LiabilityAssetOfDefinedBenefitPlans
2333 1153 - Disclosure - Post-Retirement Obligations - Disclosure of Changes in the Fair Value of Plan Assets (Detail) Network

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2334 Disclosure of fair value of plan assets [table] Table

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2335 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
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2337 Pension plans and retirement supplement plans [member] Member xcmig:PensionPlansAndRetirementSupplementPlansMember
2338 Disclosure of fair value of plan assets [line items] LineItems ifrs-full:DisclosureOfFairValueOfPlanAssetsLineItems
2339 Beginning balance Concept (Monetary) As Of Debit ifrs-full:PlanAssetsAtFairValue
2340 Real return on the investments Concept (Monetary) For Period Debit ifrs-full:ReturnOnPlanAssetsNetDefinedBenefitLiabilityAsset
2341 Contributions from the employer Concept (Monetary) For Period Debit ifrs-full:ContributionsToPlanByEmployerNetDefinedBenefitLiabilityAsset
2342 Benefits paid Concept (Monetary) For Period Debit ifrs-full:PaymentsFromPlanNetDefinedBenefitLiabilityAsset
2343 Ending balance Concept (Monetary) As Of Debit ifrs-full:PlanAssetsAtFairValue
2344 1154 - Disclosure - Post-Retirement Obligation - Disclosure of Defined Benefit Plans Expense Recognised in Income Statement (Detail) Network

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2345 Disclosure of fair value of plan assets [table] Table

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2346 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
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2348 Pension plans and retirement supplement plans [member] Member xcmig:PensionPlansAndRetirementSupplementPlansMember
2349 Health plan [member] Member xcmig:HealthPlanMember
2350 Dental plan [member] Member xcmig:DentalPlanMember
2351 Life insurance [member] Member xcmig:LifeInsuranceMember
2352 Net defined benefit liability (asset) [axis] Axis ifrs-full:NetDefinedBenefitLiabilityAssetAxis
2353 Net defined benefit liability (asset) [member] Member ifrs-full:NetDefinedBenefitLiabilityAssetMember
2354 Expense as per actuarial opinion [member] Member xcmig:ExpenseAsPerActuarialOpinionMember
2355 Adjustment relating to debt [member] Member xcmig:AdjustmentRelatingToDebtMember
2356 Disclosure of fair value of plan assets [line items] LineItems ifrs-full:DisclosureOfFairValueOfPlanAssetsLineItems
2357 Cost of current service Concept (Monetary) For Period Credit ifrs-full:CurrentServiceCostNetDefinedBenefitLiabilityAsset
2358 Interest on the actuarial obligation Concept (Monetary) For Period Credit ifrs-full:InterestExpenseIncomeNetDefinedBenefitLiabilityAsset
2359 Expected return on the assets of the Plan Concept (Monetary) For Period Debit xcmig:ExpectedReturnOnPlanAssetsNetDefinedBenefitLiabilityAsset
2360 Past service cost Concept (Monetary) For Period Credit ifrs-full:PastServiceCostNetDefinedBenefitLiabilityAsset
2361 Expense according to actuarial calculation Concept (Monetary) For Period Debit xcmig:ExpenseNetDefinedBenefitLiabilityAsset
2362 1155 - Disclosure - Post-Retirement Obligation - Summary of Changes in Net Liabilities (Detail) Network

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2363 Disclosure of defined benefit plans [table] Table

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 ifrs-full:DisclosureOfDefinedBenefitPlansTable
2364 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
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2366 Pension plans and retirement supplement plans [member] Member xcmig:PensionAndRetirementSupplementPlansMember
2367 Health plan [member] Member xcmig:HealthPlanMember
2368 Dental plan [member] Member xcmig:DentalPlanMember
2369 Life insurance [member] Member xcmig:LifeInsurancePlanMember
2370 Disclosure of defined benefit plans [line items] LineItems ifrs-full:DisclosureOfDefinedBenefitPlansLineItems
2371 Current liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentRecognisedLiabilitiesDefinedBenefitPlan
2372 Non-currentliabilities Concept (Monetary) As Of Credit ifrs-full:NoncurrentRecognisedLiabilitiesDefinedBenefitPlan
2373 Net liabilities, Beginning balance Concept (Monetary) As Of Debit ifrs-full:SurplusDeficitInPlan
2374 Expense recognized in Statement of income Concept (Monetary) For Period Debit xcmig:PostRetirementExpensesRecognizedInStatementOfIncome
2375 Contributions paid Concept (Monetary) For Period Credit ifrs-full:EmployerContributions
2376 Plan amendment - Past service Concept (Monetary) For Period Credit ifrs-full:PastServiceCostAndGainsLossesArisingFromSettlementsNetDefinedBenefitLiabilityAsset
2377 Actuarial losses (gains) Concept (Monetary) For Period Debit ifrs-full:ActuarialGainsLossesArisingFromChangesInFinancialAssumptionsNetDefinedBenefitLiabilityAsset
2378 Net liabilities, Ending balance Concept (Monetary) As Of Debit ifrs-full:SurplusDeficitInPlan
2379 1156 - Disclosure - Post-Retirement Obligation- Summary of Independent Actuaries Estimate for the Expense Amount (Detail) Network

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2380 Disclosure of defined benefit plans [table] Table

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2381 Net defined benefit liability (asset) [axis] Axis ifrs-full:NetDefinedBenefitLiabilityAssetAxis
2382 Net defined benefit liability (asset) [member] Member ifrs-full:NetDefinedBenefitLiabilityAssetMember
2383 2017 business year [Member] Member xcmig:TwoThousandTwentySevenMember
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2385 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
2386 Pension plans and retirement supplement plans [member] Member xcmig:PensionAndRetirementSupplementPlansMember
2387 Health plan [member] Member xcmig:HealthPlanMember
2388 Dental plan [member] Member xcmig:DentalPlanMember
2389 Life insurance [member] Member xcmig:LifeInsurancePlanMember
2390 Disclosure of defined benefit plans [line items] LineItems ifrs-full:DisclosureOfDefinedBenefitPlansLineItems
2391 Cost of current service Concept (Monetary) For Period Credit ifrs-full:CurrentServiceCostNetDefinedBenefitLiabilityAsset
2392 Interest on the actuarial obligation Concept (Monetary) For Period Credit ifrs-full:InterestExpenseIncomeNetDefinedBenefitLiabilityAsset
2393 Expected return on the assets of the Plan Concept (Monetary) For Period Debit ifrs-full:ReturnOnPlanAssetsNetDefinedBenefitLiabilityAsset
2394 Total expense in 2018 as per actuarial opinion Concept (Monetary) For Period Debit ifrs-full:ActuarialGainsLossesArisingFromChangesInFinancialAssumptionsNetDefinedBenefitLiabilityAsset
2395 1157 - Disclosure - Post-Retirement Obligation - Summary of Expectation for Payment of Benefits (Detail) Network

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2396 Disclosure of defined benefit plans [table] Table

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 ifrs-full:DisclosureOfDefinedBenefitPlansTable
2397 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
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2399 Pension plans and retirement supplement plans [member] Member xcmig:PensionAndRetirementSupplementPlansMember
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2401 Dental plan [member] Member xcmig:DentalPlanMember
2402 Life insurance [member] Member xcmig:LifeInsurancePlanMember
2403 Disclosure of defined benefit plans [line items] LineItems ifrs-full:DisclosureOfDefinedBenefitPlansLineItems
2404 Estimate of payment of benefits Concept (Monetary) For Period Credit ifrs-full:EstimateOfContributionsExpectedToBePaidToPlan
2405 1158 - Disclosure - Post-Retirement Liabilities - Summary of Average Periods of the Obligations Under the Benefit Plans (Detail) Network

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*

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2406 Disclosure of Information About Maturity Profile of Defined Benefit Obligation [Table] Table

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 xcmig:DisclosureOfInformationAboutMaturityProfileOfDefinedBenefitObligationTable
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2410 Plan B [member] Member xcmig:PensionAndRetirementSupplementPlansPlanBMember
2411 Health plan [member] Member xcmig:HealthPlanMember
2412 Dental plan [member] Member xcmig:DentalPlanMember
2413 Life insurance [member] Member xcmig:LifeInsurancePlanMember
2414 Disclosure of Information About Maturity Profile of Defined Benefit Obligation [Line Items] LineItems xcmig:DisclosureOfInformationAboutMaturityProfileOfDefinedBenefitObligationLineItems
2415 Average periods of maturity of the obligations under the benefit plans Concept (xbrli:durationItemType) For Period xcmig:MaturityPeriodOfDefinedBenefitPlans
2416 1159 - Disclosure - Post-Retirement Obligation - Summary of Principal Categories Percentage of Plan Assets (Detail) Network

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2417 Implied Table Table

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*

 implied:Table
2418 Disclosure of fair value of plan assets [abstract] Abstract ifrs-full:DisclosureOfFairValueOfPlanAssetsAbstract
2419 Shares in Brazilian companies Concept (Percent) As Of xcmig:PercentageOfPlanAssetsSharesOfBrazilianCompanies
2420 Fixed income securities Concept (Percent) As Of xcmig:PercentageOfPlanAssetsFixedIncomeSecurities
2421 Real estate property Concept (Percent) As Of xcmig:PercentageOfPlanAssetsRealEstateProperty
2422 Others Concept (Percent) As Of xcmig:PercentageOfPlanAssetsOther
2423 Total Concept (Percent) As Of xcmig:PercentageOfPlanAssets
2424 1160 - Disclosure - Post-Retirement Obligation - Summary of Fair Value of Pension Plan Assets Issued by Sponsor and Subsidiaries (Detail) Network

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2425 Disclosure of fair value of plan assets [table] Table

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*

 ifrs-full:DisclosureOfFairValueOfPlanAssetsTable
2426 Net defined benefit liability (asset) [axis] Axis ifrs-full:NetDefinedBenefitLiabilityAssetAxis
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2429 Shares issued by the Company [member] Member xcmig:SharesissuedByTheCompanyMember
2430 Real estate properties of the Foundation, occupied by the Company and subsidiaries [member] Member xcmig:RealEstatePropertiesByCompanyMember
2431 Disclosure of fair value of plan assets [line items] LineItems ifrs-full:DisclosureOfFairValueOfPlanAssetsLineItems
2432 Assets of the pension plan Concept (Monetary) As Of Debit ifrs-full:AssetbackedSecuritiesAmountContributedToFairValueOfPlanAssets
2433 1161 - Disclosure - Post-Retirement Obligation- Summary of Actuarial Assumptions (Detail) Network

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2434 Implied Table Table

*

*

 implied:Table
2435 Disclosure of fair value of plan assets [abstract] Abstract ifrs-full:DisclosureOfFairValueOfPlanAssetsAbstract
2436 Annual discount rate for present value of the actuarial obligation Concept (Percent) As Of ifrs-full:ActuarialAssumptionOfDiscountRates
2437 Annual expected return on plan assets Concept (Percent) For Period xcmig:ActuarialAssumptionAnnualExpectedReturnOnPlanAssets
2438 Long-term annual inflation rate Concept (Percent) As Of ifrs-full:ActuarialAssumptionOfExpectedRatesOfInflation
2439 Estimated future annual salary increases Concept (Percent) As Of ifrs-full:ActuarialAssumptionOfExpectedRatesOfSalaryIncreases
2440 General mortality table Concept (Text/String) For Period xcmig:ActuarialAssumptionMortalityRate
2441 Disability table Concept (Text/String) For Period xcmig:ActuarialAssumptionDisabilityRate
2442 Disabled mortality table Concept (Text/String) For Period xcmig:ActuarialAssumptionDisabledMortalityRate
2443 1162 - Disclosure - Post-Retirement Obligation- Summary of Sensitivity Analysis of the Effects of Changes in the Principal Actuarial Assumptions Used to Determine the Defined-benefit Obligation (Detail) Network

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2444 Disclosure of sensitivity analysis for actuarial assumptions [table] Table

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*

 ifrs-full:DisclosureOfSensitivityAnalysisForActuarialAssumptionsTable
2445 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
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2447 Pension plans and retirement supplement plans [member] Member xcmig:PensionAndRetirementSupplementPlansMember
2448 Health plan [member] Member xcmig:HealthPlanMember
2449 Dental plan [member] Member xcmig:DentalPlanMember
2450 Life insurance [member] Member xcmig:LifeInsurancePlanMember
2451 Disclosure of sensitivity analysis for actuarial assumptions [line items] LineItems ifrs-full:DisclosureOfSensitivityAnalysisForActuarialAssumptionsLineItems
2452 Reduction of one year in the mortality table Concept (Monetary) As Of Credit ifrs-full:IncreaseDecreaseInDefinedBenefitObligationDueToReasonablyPossibleDecreaseInActuarialAssumption
2453 Increase of one year in the mortality table Concept (Monetary) As Of Credit ifrs-full:IncreaseDecreaseInDefinedBenefitObligationDueToReasonablyPossibleIncreaseInActuarialAssumption
2454 Reduction of 1% in the discount rate Concept (Monetary) As Of Credit xcmig:ReductionOfOnePercentInDiscountRate
2455 1163 - Disclosure - Post-Retirement Obligation- Summary of Sensitivity Analysis of the Effects of Changes in the Principal Actuarial Assumptions Used to Determine the Defined-benefit Obligation (Parenthetical) (Detail) Network

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2456 Disclosure of sensitivity analysis for actuarial assumptions [table] Table

*

*

 ifrs-full:DisclosureOfSensitivityAnalysisForActuarialAssumptionsTable
2457 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
2458 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
2459 Pension plans and retirement supplement plans [member] Member xcmig:PensionAndRetirementSupplementPlansMember
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2461 Dental plan [member] Member xcmig:DentalPlanMember
2462 Life insurance [member] Member xcmig:LifeInsurancePlanMember
2463 Disclosure of sensitivity analysis for actuarial assumptions [line items] LineItems ifrs-full:DisclosureOfSensitivityAnalysisForActuarialAssumptionsLineItems
2464 Discount rate Concept (Percent) As Of ifrs-full:PercentageOfReasonablyPossibleDecreaseInActuarialAssumption
2465 1164 - Disclosure - Provisions - Schedule of Provisions for contingencies (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureProvisionsScheduleOfProvisionsForContingencies
2466 Disclosure of other provisions [table] Table

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*

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2467 Classes of other provisions [axis] Axis ifrs-full:ClassesOfProvisionsAxis
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2470 Customer relations [member] Member xcmig:CustomerRelationsMember
2471 Other civil actions [member] Member xcmig:OtherCivilActionsMember
2472 Civil cases [Member] Member xcmig:CivilCasesMember
2473 Tax [member] Member ifrs-full:ProvisionForTaxesOtherThanIncomeTaxMember
2474 Environment [member] Member ifrs-full:OtherEnvironmentRelatedProvisionMember
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2476 Corporate [Member] Member xcmig:CorporateOtherProvisionsMember
2477 Other [member] Member ifrs-full:MiscellaneousOtherProvisionsMember
2478 Consumer relations [member] Member xcmig:ConsumerRelationsMember
2479 Disclosure of other provisions [line items] LineItems ifrs-full:DisclosureOfOtherProvisionsLineItems
2480 Other provisions Beginning Balance Concept (Monetary) As Of Credit ifrs-full:OtherProvisions
2481 Additions Concept (Monetary) For Period Credit ifrs-full:AdditionalProvisionsOtherProvisions
2482 Reversals Concept (Monetary) For Period Debit ifrs-full:UnusedProvisionReversedOtherProvisions
2483 Closed Concept (Monetary) For Period Debit xcmig:ClosedProvisionsOtherProvisions
2484 Other provisions ending balance Concept (Monetary) As Of Credit ifrs-full:OtherProvisions
2485 1165 - Disclosure - Provisions - Additional Information (Detail) Network

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2486 Disclosure of provisions and contingencies [Table] Table

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*

 xcmig:DisclosureOfProvisionsAndContingenciesTable
2487 Classes of other provisions [axis] Axis ifrs-full:ClassesOfProvisionsAxis
2488 Other provisions [member] Member ifrs-full:OtherProvisionsMember
2489 Labor claims [member] Member xcmig:LaborClaimsMember
2490 Corporate [Member] Member xcmig:CorporateOtherProvisionsMember
2491 Customers claims [member] Member xcmig:CustomersClaimsMember
2492 Tax [member] Member ifrs-full:ProvisionForTaxesOtherThanIncomeTaxMember
2493 IPTU Urban Land Tax to real estate properties [member] Member xcmig:IPTUUrbanLandTaxToRealEstatePropertiesMember
2494 Environment [member] Member ifrs-full:OtherEnvironmentRelatedProvisionMember
2495 Regulatory [member] Member xcmig:RegulatoryOtherProvisionsMember
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2500 Higher Appeal Court And Federal Supreme Court [member] Member xcmig:HigherAppealCourtAndFederalSupremeCourtMember
2501 Early settlement of earnings compensation account [member] Member xcmig:EarlySettlementOfEarningsCompensationAccountMember
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2503 Social Security Contributions [member] Member xcmig:SocialSecurityContributionsMember
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2509 Income tax withheld at sourced on capital gain in stockholding transaction [member] Member xcmig:IncomeTaxWithheldAtSourcedOnCapitalGainInStockholdingTransactionMember
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2530 voting shares percentage Concept (Percent) As Of ifrs-full:PercentageOfVotingEquityInterestsAcquired
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2541 1166 - Disclosure - Equity and Remuneration to Shareholders - Additional Information (Detail) Network

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*

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2542 Disclosure of reserves within equity [table] Table

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2576 1167 - Disclosure - Equity and Remuneration to Shareholders - Summary of Share Capital for Common Shares and Preferred Shares (Detail) Network

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2577 Statement of changes in equity [table] Table

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*

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2583 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
2584 Minas Gerais State [Member] Member xcmig:StateOfMinasGeraisMember
2585 Other entities of M.G. State [Member] Member xcmig:OtherEntitiesOfMinasGeraisStateMember
2586 FIA Dinamica Energia S.A. [member] Member xcmig:FIADinamicaEnergiaSAMember
2587 Other Shareholders In Brazil [Member] Member xcmig:OtherShareholdersInBrazilMember
2588 Foreign shareholders [member] Member xcmig:ForeignShareholdersMember
2589 AGC Energia S.A. [Member] Member xcmig:AgcEnergiaSaMember
2590 Statement of changes in equity [line items] LineItems ifrs-full:StatementOfChangesInEquityLineItems
2591 Number of shares issued Concept (Shares) As Of ifrs-full:NumberOfSharesIssued
2592 Percentage of changes in share capital Concept (Percent) As Of xcmig:PercentageOfChangesInShareCapital
2593 1168 - Disclosure - Equity and Remuneration to Shareholders - Summary of Shares used in Calculation of Basic Profit and Diluted Earnings per Share (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureEquityAndRemunerationToShareholdersSummaryOfSharesUsedInCalculationOfBasicProfitAndDilutedEarningsPerShare
2594 Earnings per share [table] Table

*

*

 ifrs-full:EarningsPerShareTable
2595 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
2596 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
2597 Common shares [member] Member xcmig:CommonSharesMember
2598 Preference shares [member] Member ifrs-full:PreferenceSharesMember
2599 Earnings per share [line items] LineItems ifrs-full:EarningsPerShareLineItems
2600 Common shares already paid up Concept (Shares) As Of ifrs-full:NumberOfSharesIssuedAndFullyPaid
2601 Common shares to be paid up Concept (Shares) As Of ifrs-full:NumberOfSharesIssuedButNotFullyPaid
2602 Shares in treasury Concept (Shares) As Of xcmig:NumberOfTreasuryShares
2603 Number of shares outstanding Concept (Shares) As Of ifrs-full:NumberOfSharesOutstanding
2604 1169 - Disclosure - Equity and Remuneration to Shareholders - Summary of Calculation of Basic Earnings per Share (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureEquityAndRemunerationToShareholdersSummaryOfCalculationOfBasicEarningsPerShare
2605 Earnings per share [table] Table

*

*

 ifrs-full:EarningsPerShareTable
2606 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
2607 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
2608 Preferred shares [member] Member xcmig:PreferredSharesMember
2609 Common shares [member] Member xcmig:CommonSharesMember
2610 Earnings per share [line items] LineItems ifrs-full:EarningsPerShareLineItems
2611 Net income for the year Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromContinuingOperations
2612 Minimum mandatory dividend for preferred shares from income for the period (item c) Concept (Monetary) For Period Credit xcmig:MinimumMandatoryDividend
2613 Income not distributed arising from the net income for the period - common shares Concept (Monetary) For Period Credit xcmig:UndistributedEarningsFromProfit
2614 Total earnings for the common shares (B) Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromContinuingOperationsAttributableToOrdinaryEquityHoldersOfParentEntity
2615 Basic earnings per common share ( B / number of common shares ) Concept (Share) For Period ifrs-full:BasicEarningsLossPerShare
2616 1170 - Disclosure - Equity and Remuneration to Shareholders - Summary of Calculation of Diluted Earnings per Share (Detail) Network

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*

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2617 Earnings per share [table] Table

*

*

 ifrs-full:EarningsPerShareTable
2618 Classes of financial assets [axis] Axis ifrs-full:ClassesOfFinancialAssetsAxis
2619 Financial assets, class [member] Member ifrs-full:FinancialAssetsMember
2620 RME/Lepsa Option [Member] Member xcmig:RMEAndLepsaOptionsMember
2621 Ativas Option [Member] Member xcmig:AtivasOptionsMember
2622 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
2623 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
2624 Preferred shares [member] Member xcmig:PreferredSharesMember
2625 Common shares [member] Member xcmig:CommonSharesMember
2626 Earnings per share [line items] LineItems ifrs-full:EarningsPerShareLineItems
2627 Net income for the year Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromContinuingOperations
2628 Total basic earnings for the preferred shares Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromContinuingOperationsAttributableToOrdinaryEquityHoldersOfParentEntity
2629 Dilutive effect Concept (Shares) For Period ifrs-full:DilutiveEffectOfShareOptionsOnNumberOfOrdinaryShares
2630 Diluted earnings for the common shares (D) Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromContinuingOperationsAttributableToOrdinaryEquityHoldersOfParentEntityIncludingDilutiveEffects
2631 Diluted earnings per common share ( D / No. of common shares ) Concept (Share) For Period ifrs-full:DilutedEarningsLossPerShare
2632 1171 - Disclosure - Equity and Remuneration to Shareholders - Reserves - Schedule of Capital Reserves and Profit Reserves (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureEquityAndRemunerationToShareholdersReservesScheduleOfCapitalReservesAndProfitReserves
2633 Implied Table Table

*

*

 implied:Table
2634 Disclosure of reserves within equity [abstract] Abstract ifrs-full:DisclosureOfReservesWithinEquityAbstract
2635 Investment-related subsidies Concept (Monetary) As Of Credit xcmig:InvestmentRelatedSubsidies
2636 Goodwill on issuance of shares Concept (Monetary) As Of Credit ifrs-full:AdditionalPaidinCapital
2637 Shares in treasury Concept (Monetary) As Of Debit ifrs-full:TreasuryShares
2638 Capital reserves and shares in Treasury Concept (Monetary) As Of Credit ifrs-full:CapitalReserve
2639 Legal reserve Concept (Monetary) As Of Credit xcmig:LegalReserve
2640 Statutory Reserve Concept (Monetary) As Of Credit ifrs-full:StatutoryReserve
2641 Retained earnings reserve Concept (Monetary) As Of Credit xcmig:RetainedEarningsReserve
2642 Incentives tax reserve Concept (Monetary) As Of Credit xcmig:TaxIncentivesReserve
2643 Reserve for mandatory dividends not distributed Concept (Monetary) As Of Credit xcmig:ReserveForMandatoryDividendsNotDistributed
2644 Profit reserves Concept (Monetary) As Of Credit ifrs-full:RetainedEarnings
2645 1172 - Disclosure - Equity and Remuneration to Shareholders - Summary of Reserve for Obligatory Dividends Not Distributed (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureEquityAndRemunerationToShareholdersSummaryOfReserveForObligatoryDividendsNotDistributed
2646 Disclosure of reserves within equity [table] Table

*

*

 ifrs-full:DisclosureOfReservesWithinEquityTable
2647 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
2648 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
2649 Dividends withheld, arising from the profit for 2015 [member] Member xcmig:DividendsWithheldArisingFromTheProfitFor2015Member
2650 Dividends withheld, arising from the profit for 2014 [member] Member xcmig:DividendsWithheldArisingFromTheProfitFor2014Member
2651 Disclosure of reserves within equity [line items] LineItems ifrs-full:DisclosureOfReservesWithinEquityLineItems
2652 Dividends withheld, arising from the net income Concept (Monetary) As Of Credit xcmig:ReserveForMandatoryDividendsNotDistributed
2653 1173 - Disclosure - Equity and Remuneration to Shareholders - Schedule of Dividends Proposed for Distribution to Shareholders Based on the Profit for the Business Year (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureEquityAndRemunerationToShareholdersScheduleOfDividendsProposedForDistributionToShareholdersBasedOnTheProfitForTheBusinessYear
2654 Disclosure of Dividends [Table] Table

*

*

 xcmig:DisclosureOfDividendsTable
2655 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
2656 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
2657 Preference shares [member] Member ifrs-full:PreferenceSharesMember
2658 Components of equity [axis] Axis ifrs-full:ComponentsOfEquityAxis
2659 Equity [member] Member ifrs-full:EquityMember
2660 Dividend distribution [Member] Member xcmig:DividendDistributionMember
2661 Disclosure of Dividends [Line Items] LineItems xcmig:DisclosureOfDividendsLineItems
2662 Nominal value of the preferred shares Concept (Monetary) As Of Debit xcmig:NominalValuePreferenceSharesHeld
2663 Nominal value of the preferred shares to be capitalized Concept (Monetary) As Of Credit xcmig:NominalValueOfPreferredSharesToBeCapitalized
2664 Preferred shares Concept (Monetary) As Of Credit xcmig:PreferredShares
2665 Percentage applied to the nominal value of the preferred shares Concept (Percent) For Period xcmig:MinimumAnnualDividendPercentageOnParValue
2666 Amount of the dividends by the First payment criterion Concept (Monetary) For Period Debit xcmig:DividendsPaidFirstInstallment
2667 Equity Concept (Monetary) As Of Credit ifrs-full:Equity
2668 Preferred shares as a percentage of Equity (net of shares held in Treasury) Concept (Percent) As Of xcmig:PercentageOfPreferredSharesInShareCapital
2669 Percentage applied to the portion of Equity represented by the preferred shares Concept (Percent) For Period xcmig:MinimumAnnualDividendPercentageOnPortionOfEquity
2670 Amount of the dividends by the Second payment criterion Concept (Monetary) For Period Debit xcmig:DividendsPaidSecondInstallment
2671 Minimum Dividends required by the Bylaws for the preferred shares Concept (Monetary) For Period Debit xcmig:MinimumDividendUnderByLaws
2672 Net income for the year Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromContinuingOperations
2673 Mandatory dividends - 50% of Net income Concept (Monetary) For Period Debit xcmig:MandatoryDividendPayoutAsPercentageOfNetProfit
2674 1174 - Disclosure - Equity and Remuneration to Shareholders - Schedule of Dividends Proposed for Distribution to Shareholders Based on the Profit for the Business Year (Parenthetical) (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureEquityAndRemunerationToShareholdersScheduleOfDividendsProposedForDistributionToShareholdersBasedOnTheProfitForTheBusinessYearParenthetical
2675 Disclosure of Dividends [Table] Table

*

*

 xcmig:DisclosureOfDividendsTable
2676 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
2677 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
2678 Preference shares [member] Member ifrs-full:PreferenceSharesMember
2679 Components of equity [axis] Axis ifrs-full:ComponentsOfEquityAxis
2680 Equity [member] Member ifrs-full:EquityMember
2681 Dividend distribution [Member] Member xcmig:DividendDistributionMember
2682 Disclosure of Dividends [Line Items] LineItems xcmig:DisclosureOfDividendsLineItems
2683 Dividend percentage of net income Concept (Percent) As Of xcmig:DividendPercentageOfNetIncome
2684 1175 - Disclosure - Equity and Remuneration to Shareholders - Summary of Equity Valuation Adjustments (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureEquityAndRemunerationToShareholdersSummaryOfEquityValuationAdjustments
2685 Implied Table Table

*

*

 implied:Table
2686 Miscellaneous equity [abstract] Abstract ifrs-full:MiscellaneousEquityAbstract
2687 Deemed cost of PP&E Concept (Monetary) As Of Credit xcmig:DeemedCostOfPropertyPlantAndEquipmentReserve
2688 Accumulated Other Comprehensive Income Variation in fair value of financial asset available for sale in jointly-controlled entity Concept (Monetary) As Of Credit xcmig:AccumulatedOtherComprehensiveIncomeVariationInFairValueOfFinancialAssetAvailableForSaleInJointlycontrolledEntity
2689 Cumulative translation adjustments Concept (Monetary) As Of Credit xcmig:AccumulatedOtherComprehensiveIncomeCumulativeTranslationAdjustments
2690 Adjustments to actuarial liabilities - Employee benefits Concept (Monetary) As Of Credit xcmig:AccumulatedOtherComprehensiveIncomeAdjustmentsToActuarialLiabilitiesEmployeeBenefits
2691 Equity valuation adjustments Concept (Monetary) As Of Credit xcmig:EquityValuationReserve
2692 1176 - Disclosure - Revenues - Summary of Net Operating Revenue (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureRevenuesSummaryOfNetOperatingRevenue
2693 Implied Table Table

*

*

 implied:Table
2694 Revenue [abstract] Abstract ifrs-full:RevenueAbstract
2695 Revenue from supply of energy Concept (Monetary) For Period Credit ifrs-full:RevenueFromSaleOfElectricity
2696 Revenue from use of the electricity distribution systems (TUSD) Concept (Monetary) For Period Credit xcmig:RevenueFromElectricityDistributionSystem
2697 CVA, and Other financial components in tariff increases Concept (Monetary) For Period Credit xcmig:RevenueFromCVAAndOtherFinancialComponents
2698 Transmission concession revenue Concept (Monetary) For Period Credit xcmig:RevenueFromTransmissionConcession
2699 Transmission construction revenue Concept (Monetary) For Period Credit xcmig:RevenueFromTransmissionConstruction
2700 Transmission indemnity revenue Concept (Monetary) For Period Credit xcmig:RevenueFromTransmissionIndemnity
2701 Generation indemnity revenue Concept (Monetary) For Period Credit xcmig:RevenueFromGenerationIndemnity
2702 Distribution construction revenue Concept (Monetary) For Period Credit ifrs-full:RevenueFromConstructionContracts
2703 Adjustment to expectation of cash flow from indemnifiable Financial asset of distribution concession Concept (Monetary) For Period Credit xcmig:RevenueFromDistributionConcession
2704 Revenue from financial updating of the Concession Grant Fee Concept (Monetary) For Period Credit xcmig:RevenueFromConcessionGrantFee
2705 Energy transactions on the CCEE Concept (Monetary) For Period Credit xcmig:RevenueFromTransactionsInElectricity
2706 Supply of gas Concept (Monetary) For Period Credit ifrs-full:RevenueFromSaleOfNaturalGas
2707 Other operating revenues Concept (Monetary) For Period Credit ifrs-full:OtherRevenue
2708 Deductions on revenue Concept (Monetary) For Period Debit xcmig:DeductionsFromRevenues
2709 Net operating revenue Concept (Monetary) For Period Credit ifrs-full:Revenue
2710 1177 - Disclosure - Revenues - Summary of the Supply of Electricity by Type of Consumer (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureRevenuesSummaryOfTheSupplyOfElectricityByTypeOfConsumer
2711 Disclosure of Revenue [Table] Table

*

*

 xcmig:DisclosureOfRevenueTable
2712 Types of rate-regulated activities [axis] Axis ifrs-full:TypesOfRateregulatedActivitiesAxis
2713 Rate-regulated activities [member] Member ifrs-full:RateregulatedActivitiesMember
2714 Electricity Distribution [member] Member ifrs-full:ElectricityDistributionMember
2715 Types of customers [axis] Axis ifrs-full:TypesOfCustomersAxis
2716 Types of customers [member] Member ifrs-full:TypesOfCustomersMember
2717 Residential [member] Member xcmig:ResidentialMember
2718 Industrial [member] Member xcmig:IndustrialMember
2719 Commercial, services and others [member] Member xcmig:CommercialServicesAndOtherMember
2720 Rural [member] Member xcmig:RuralMember
2721 Public authorities [member] Member xcmig:PublicAuthoritiesMember
2722 Public Lighting [member] Member xcmig:PublicLightingMember
2723 Public service [member] Member xcmig:PublicServiceMember
2724 Disclosure of revenue [Line Items] LineItems xcmig:DisclosureOfRevenueLineItems
2725 Supply of electricity in GWh Concept (num:energyItemType) For Period xcmig:SupplyOfElectricityGross
2726 Own consumption Concept (num:energyItemType) For Period xcmig:SupplyOfElectricityInGwhForOwnConsumption
2727 Unbilled revenue Concept (num:energyItemType) For Period xcmig:SupplyOfElectricityInGwhForUnbilledRevenue
2728 Supply of electricity including own consumption and not invoiced Concept (num:energyItemType) For Period xcmig:SupplyOfElectricityInGwhIncludingOwnConsumptionAndNotInvoiced
2729 Wholesale supply to other concession holders Concept (num:energyItemType) For Period xcmig:WholesaleSupplyOfElectricityInGwhToOtherConcessionHolder
2730 Wholesale supply unbilled, net Concept (num:energyItemType) For Period xcmig:WholesaleSupplyOfElectricityInGwhToUnbilled
2731 Total Concept (num:energyItemType) For Period xcmig:SupplyOfElectricity
2732 Revenue from sale of electricity Concept (Monetary) For Period Credit xcmig:RevenueFromSaleOfElectricityGross
2733 Own consumption Concept (Monetary) For Period Credit xcmig:SupplyOfElectricityForOwnConsumption
2734 Unbilled revenue Concept (Monetary) As Of Debit xcmig:UnbilledRevenues
2735 Supply of electricity including own consumption and not invoiced Concept (Monetary) For Period Credit xcmig:SupplyOfElectricityIncludingOwnConsumptionAndNotInvoiced
2736 Wholesale supply to other concession holders Concept (Monetary) For Period Credit xcmig:WholesaleSupplyOfElectricityToOtherConcessionHolder
2737 Wholesale supply unbilled, net Concept (Monetary) For Period Credit xcmig:WholesaleSupplyOfElectricityUnbilled
2738 Revenue from sale of electricity Concept (Monetary) For Period Credit ifrs-full:RevenueFromSaleOfElectricity
2739 1178 - Disclosure - Revenues - Additional Information (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureRevenuesAdditionalInformation
2740 Implied Table Table

*

*

 implied:Table
2741 Revenue [abstract] Abstract ifrs-full:RevenueAbstract
2742 Transmission indemnity revenue Concept (Monetary) For Period Credit xcmig:RevenueFromTransmissionIndemnity
2743 Revenue from indemnity by IPCA Concept (Monetary) For Period Credit xcmig:RevenueFromIndemnityReceivableByExtendedConsumerPriceIndex
2744 Adjustment of BRR of transmission assets Concept (Monetary) For Period Credit xcmig:AdjustmentOfBrrOfTransmissionAssets
2745 Generation indemnity revenue Concept (Monetary) For Period Credit xcmig:RevenueFromGenerationIndemnity
2746 1179 - Disclosure - Revenues - Summary of Other Operating Revenues (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureRevenuesSummaryOfOtherOperatingRevenues
2747 Disclosure of Revenue [Table] Table

*

*

 xcmig:DisclosureOfRevenueTable
2748 Products and services [axis] Axis ifrs-full:ProductsAndServicesAxis
2749 Products and services [member] Member ifrs-full:ProductsAndServicesMember
2750 Charged service [Member] Member xcmig:ChargedServiceMember
2751 Telecoms services [Member] Member xcmig:TelecommunicationServicesMember
2752 Services rendered [Member] Member xcmig:ServicesRenderedMember
2753 Subsidies [Member] Member xcmig:TariffSubsidiesMember
2754 Rental and leasing [Member] Member xcmig:RentalAndLeasingMember
2755 Other [Member] Member xcmig:OtherServicesMember
2756 Disclosure of revenue [Line Items] LineItems xcmig:DisclosureOfRevenueLineItems
2757 Other revenue Concept (Monetary) For Period Credit ifrs-full:OtherRevenue
2758 1180 - Disclosure - Revenues - Summary of Deductions from Revenue (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureRevenuesSummaryOfDeductionsFromRevenue
2759 Disclosure of Revenue [Table] Table

*

*

 xcmig:DisclosureOfRevenueTable
2760 Types of rate-regulated activities [axis] Axis ifrs-full:TypesOfRateregulatedActivitiesAxis
2761 Rate-regulated activities [member] Member ifrs-full:RateregulatedActivitiesMember
2762 ICMS [member] Member xcmig:ICMSTaxesMember
2763 Cofins [member] Member xcmig:CofinsTaxMember
2764 PIS and Pasep [member] Member xcmig:PisAndPasepTaxMember
2765 Other [Member] Member xcmig:OtherTaxesMember
2766 Global Reversion Reserve - RGR [Member] Member xcmig:GlobalReversionReserveMember
2767 Energy Efficiency Program (P.E.E.) [Member] Member xcmig:EnergyEfficiencyProgramMember
2768 Energy Development Account - CDE [Member] Member xcmig:EnergyDevelopmentAccountMember
2769 Research and Development - P&D [Member] Member xcmig:ResearchAndDevelopmentMember
2770 National Scientific and Technological Development Fund - FNDCT [Member] Member xcmig:NationalScientificAndTechnologicalDevelopmentFundMember
2771 Energy System Expansion Research - EPE [Member] Member xcmig:EnergySystemExpansionResearchMember
2772 Customer charges - Proinfa alternative sources program [Member] Member xcmig:ProinfaAlternativeSourceMember
2773 Energy Services Inspection Charge [Member] Member xcmig:ElectricityServiceInspectionMember
2774 Royalties for use of water resources [Member] Member xcmig:RoyaltyOnWaterResourceMember
2775 Customer Charges - Tariff Flag Amounts [member] Member xcmig:TariffFlagMember
2776 Disclosure of revenue [Line Items] LineItems xcmig:DisclosureOfRevenueLineItems
2777 Taxes on revenues Concept (Monetary) For Period Debit xcmig:TaxesOnRevenues
2778 Charges to the consumer Concept (Monetary) For Period Debit xcmig:ChargesToConsumer
2779 Deductions from revenue Concept (Monetary) For Period Debit xcmig:DeductionsFromRevenues
2780 1181 - Disclosure - Revenues - Summary of Deductions from Revenue (Parenthetical) (Detail) Network

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*

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2781 Implied Table Table

*

*

 implied:Table
2782 Revenue [abstract] Abstract ifrs-full:RevenueAbstract
2783 Tax credits regularization plan amount Concept (Monetary) For Period Credit xcmig:TaxCreditsRegularizationPlanAmount
2784 Impact on income due to change in tax rate Concept (Percent) For Period xcmig:ImpactOnIncomeDueToChangeInTaxRates
2785 1182 - Disclosure - Operating Costs And Expenses - Summary of Operating Costs and Expenses (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureOperatingCostsAndExpensesSummaryOfOperatingCostsAndExpenses
2786 Implied Table Table

*

*

 implied:Table
2787 Disclosure Of Operating Costs And Expenses [Abstract] Abstract xcmig:DisclosureOfOperatingCostsAndExpensesAbstract
2788 Personnel Concept (Monetary) For Period Debit xcmig:PersonnelExpenses
2789 Employees' and managers' profit sharing Concept (Monetary) For Period Debit ifrs-full:ExpenseFromSharebasedPaymentTransactionsWithEmployees
2790 Post-retirement benefits - Note 23 Concept (Monetary) For Period Credit xcmig:PostRetirementLiabilities
2791 Materials Concept (Monetary) For Period Debit ifrs-full:RawMaterialsAndConsumablesUsed
2792 Raw materials and inputs for production of energy Concept (Monetary) For Period Debit xcmig:RawMaterialsAndInputsForProductionOfEnergy
2793 Outsourced services Concept (Monetary) For Period Debit xcmig:OutsourcedServicesExpense
2794 Energy bought for resale Concept (Monetary) For Period Debit xcmig:EnergyBoughtForResale
2795 Depreciation and amortization Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDepreciationAndAmortisationExpense
2796 Operating provisions Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForProvisions
2797 Charges for use of the national grid Concept (Monetary) For Period Debit xcmig:ChargesForUseOfNationalGrid
2798 Gas bought for resale Concept (Monetary) For Period Debit xcmig:GasBoughtForResale
2799 Construction costs Concept (Monetary) For Period Debit xcmig:ConstructionContractsCosts
2800 Other operating expenses, net Concept (Monetary) For Period Credit xcmig:MiscellaneousOtherOperatingIncomeExpense
2801 Operating costs and expenses Concept (Monetary) For Period Debit xcmig:CostsAndExpenses1
2802 1183 - Disclosure - Operating Costs And Expenses - Additional Information (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureOperatingCostsAndExpensesAdditionalInformation
2803 Implied Table Table

*

*

 implied:Table
2804 Disclosure Of Operating Costs And Expenses [Abstract] Abstract xcmig:DisclosureOfOperatingCostsAndExpensesAbstract
2805 Period of eligibility for the severance program Concept (xbrli:durationItemType) For Period xcmig:NumberOfYearsOfEmploymentEligibleForSeveranceUnderPDVPProgram
2806 Employee voluntary severance program description Concept (Text/String) For Period xcmig:EmployeeVoluntarySeveranceProgramDescription
2807 Payment of additional premium for employees joining in months Concept (xbrli:durationItemType) For Period xcmig:PaymentOfAdditionalPremiumForEmployeesJoiningInMonths
2808 Payment of premium for employees joining Concept (xbrli:durationItemType) For Period xcmig:PaymentOfPremiumForEmployeesJoiningInMonths
2809 Penalty in percentage Concept (Percent) For Period xcmig:PenaltyInPercentage
2810 Programmed voluntary retirement plan expense Concept (Monetary) For Period Debit xcmig:ProgrammedVoluntaryRetirementPlanExpense
2811 Number of employees completing severance Concept (Integer) For Period xcmig:NumberOfEmployeesCompletingSeverance
2812 1184 - Disclosure - Operating Costs And Expenses - Summary of Outsourced Services (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureOperatingCostsAndExpensesSummaryOfOutsourcedServices
2813 Implied Table Table

*

*

 implied:Table
2814 Disclosure of detailed information of outsourced services [Abstract] Abstract xcmig:DisclosureOfDetailedInformationOfOutsourcedServicesAbstract
2815 Meter reading and bill delivery Concept (Monetary) For Period Debit xcmig:MeterReadingAndBillDelivery
2816 Communication Concept (Monetary) For Period Debit xcmig:CommunicationServices
2817 Maintenance and conservation of electrical facilities and equipment Concept (Monetary) For Period Debit xcmig:MaintenanceAndConservationOfElectricalFacilitiesAndEquipment
2818 Building conservation and cleaning Concept (Monetary) For Period Debit xcmig:BuildingConservationAndCleaningServices
2819 Contracted labor Concept (Monetary) For Period Debit xcmig:ContractedLabor
2820 Freight and airfares Concept (Monetary) For Period Debit xcmig:FreightAndAirfareServices
2821 Accommodation and meals Concept (Monetary) For Period Debit xcmig:AccommodationAndMeals
2822 Security services Concept (Monetary) For Period Debit xcmig:SecurityServices
2823 Consultancy Concept (Monetary) For Period Debit xcmig:ConsultancyServices
2824 Maintenance and conservation of furniture and utensils Concept (Monetary) For Period Debit xcmig:MaintenanceAndConservationOfFurnitureAndUtensils
2825 Information technology Concept (Monetary) For Period Debit xcmig:InformationTechnology
2826 Maintenance and conservation of vehicles Concept (Monetary) For Period Debit xcmig:MaintenanceAndConservationOfVehicles
2827 Disconnection and reconnection Concept (Monetary) For Period Debit xcmig:DisconnectionAndReconnection
2828 Environment Concept (Monetary) For Period Debit xcmig:Environment
2829 Legal services Concept (Monetary) For Period Debit xcmig:LegalServices
2830 Legal procedural costs Concept (Monetary) For Period Debit xcmig:LegalServicesAndProceduralCosts
2831 Tree pruning Concept (Monetary) For Period Debit xcmig:TreePruning
2832 Cleaning of power line pathways Concept (Monetary) For Period Debit xcmig:CleaningOfPowerLinePathways
2833 Copying and legal publications Concept (Monetary) For Period Debit xcmig:CopyingAndLegalPublications
2834 Inspection of customer units Concept (Monetary) For Period Debit xcmig:InspectionOfCustomerUnits
2835 Printing of tax invoices and energy bills Concept (Monetary) For Period Debit xcmig:PrintingOfTaxInvoicesAndEnergyBills
2836 Other expenses Concept (Monetary) For Period Debit xcmig:OtherExpenses1
2837 Outsourced services Concept (Monetary) For Period Debit xcmig:OutsourcedServicesExpense
2838 1185 - Disclosure - Operating Costs And Expenses - Summary of Electricity Purchased for Resale (Detail) Network

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2839 Disclosure of Operating Costs and Expenses [Table] Table

*

*

 xcmig:DisclosureOfOperatingCostsAndExpensesTable
2840 Products and services [axis] Axis ifrs-full:ProductsAndServicesAxis
2841 Products and services [member] Member ifrs-full:ProductsAndServicesMember
2842 Supply From Itaipu Binacional [member] Member xcmig:ItaipuBinacionalMember
2843 Physical guarantee quota contracts [Member] Member xcmig:PhysicalGuaranteeContractsMember
2844 Quotas for Angra I and II Nuclear Plants [Member] Member xcmig:AngraIAndIINuclearPlantsMember
2845 Spot market [Member] Member xcmig:SpotMarketSalesMember
2846 Proinfa Program [Member] Member xcmig:ProinfaProgramMember
2847 'bilateral contracts' [Member] Member xcmig:BilateralContractsMember
2848 Electricity acquired in Regulated Market auctions [Member] Member xcmig:MarketAuctionsMember
2849 Electricity acquired in the Free Market [member] Member xcmig:FreeMarketMember
2850 Credits of Pasep and Cofins taxes [Member] Member xcmig:PasepAndCofinsTaxesMember
2851 Disclosure of operating costs and expenses [Line Items] LineItems xcmig:DisclosureOfOperatingCostsAndExpensesLineItems
2852 Energy purchased for resale Concept (Monetary) For Period Debit xcmig:EnergyPurchasedForResale
2853 1186 - Disclosure - Operating Costs And Expenses - Summary of Operating Provisions (Reversals) (Detail) Network

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*

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2854 Disclosure Of Operating Provisions Reversals [Table] Table

*

*

 xcmig:DisclosureOfOperatingProvisionsReversalsTable
2855 Continuing involvement in derecognised financial assets by type of instrument [axis] Axis ifrs-full:ContinuingInvolvementInDerecognisedFinancialAssetsByTypeOfInstrumentAxis
2856 Types of instrument [member] Member ifrs-full:TypesOfInstrumentMember
2857 Put option [Member] Member ifrs-full:WrittenPutOptionsMember
2858 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
2859 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
2860 Parati [member] Member xcmig:ParticipacoesemAtivosdeEnergiaEletricaMember
2861 SAAG [Member] Member xcmig:SAAGlnvestimentosSAMember
2862 Sonda [Member] Member xcmig:SondaProcworkOutsourcingInformaticaLtdaMember
2863 Disclosure Of Operating Provisions Reversals [Line Items] LineItems xcmig:DisclosureOfOperatingProvisionsReversalsLineItems
2864 Estimated losses on doubtful receivables Concept (Monetary) For Period Debit ifrs-full:ExpenseRecognisedDuringPeriodForBadAndDoubtfulDebtsForRelatedPartyTransaction
2865 Estimated losses on other accounts receivables Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnLoansAndReceivables
2866 Contingency provisions (reversals) Concept (Monetary) For Period Credit ifrs-full:OtherReversalsOfProvisions
2867 Labor claims Concept (Monetary) For Period Debit xcmig:ProvisionForLaborClaims
2868 Civil Concept (Monetary) For Period Debit xcmig:CivilCasesProvision
2869 Tax Concept (Monetary) For Period Debit xcmig:TaxProvision
2870 Environmental Concept (Monetary) As Of Credit xcmig:EnvironmentalProvision
2871 Regulatory Concept (Monetary) For Period Debit xcmig:RegulatoryProvisions
2872 Other Concept (Monetary) For Period Credit xcmig:OtherContingencyProvision
2873 Other provisions Concept (Monetary) As Of Credit ifrs-full:Provisions
2874 Adjustment for losses Abstract xcmig:ProvisionForLossesAbstract
2875 Provision for losses Concept (Monetary) For Period Debit xcmig:ProvisionForLosses
2876 1187 - Disclosure - Operating Costs And Expenses - Summary of Construction Cost (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureOperatingCostsAndExpensesSummaryOfConstructionCost
2877 Implied Table Table

*

*

 implied:Table
2878 Disclosure of construction cost [Abstract] Abstract xcmig:DisclosureOfConstructionCostAbstract
2879 Personnel and managers Concept (Monetary) For Period Debit xcmig:PersonnelAndManagersCost
2880 Materials Concept (Monetary) For Period Debit xcmig:MaterialConstructionCost
2881 Outsourced services Concept (Monetary) For Period Debit xcmig:OutsourcedServiceCost
2882 Others Concept (Monetary) For Period Debit xcmig:OtherConstructionCost
2883 Construction cost Concept (Monetary) For Period Debit xcmig:ConstructionContractsCosts
2884 1188 - Disclosure - Operating Costs And Expenses - Summary of Other Operating Expenses (Revenues), Net (Detail) Network

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*

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2885 Disclosure Of Other Operating Income Expense [Table] Table

*

*

 xcmig:DisclosureOfOtherOperatingIncomeExpenseTable
2886 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
2887 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
2888 Energy [member] Member xcmig:ElectricityMember
2889 CCEE (Electricity Trading Chamber) [member] Member xcmig:ElectricityTradingChamberMember
2890 Taesa [member] Member xcmig:TaesaMember
2891 Transchile Charrua Transmision SA [Member] Member xcmig:TranschileMember
2892 Disclosure Of Other Operating Income Expense [Line Items] LineItems xcmig:DisclosureOfOtherOperatingIncomeExpenseLineItems
2893 Leasing and rentals Concept (Monetary) For Period Debit xcmig:LeasingAndRentalExpenses
2894 Advertising Concept (Monetary) For Period Debit xcmig:AdvertisingExpenses
2895 Own consumption of energy Concept (Monetary) For Period Debit ifrs-full:EnergyExpense
2896 Subsidies and donations Concept (Monetary) For Period Debit ifrs-full:DonationsAndSubsidiesExpense
2897 Paid concession Concept (Monetary) For Period Debit xcmig:PaidConcession
2898 Insurance Concept (Monetary) For Period Debit ifrs-full:InsuranceExpense
2899 CCEE annual charge Concept (Monetary) For Period Debit xcmig:AnnualCharge
2900 Net loss (gain) on deactivation and disposal of assets Concept (Monetary) For Period Credit ifrs-full:GainLossRecognisedOnMeasurementToFairValueLessCostsToSellOrOnDisposalOfAssetsOrDisposalGroupsConstitutingDiscontinuedOperation
2901 Forluz - Administrative running cost Concept (Monetary) For Period Debit ifrs-full:AdministrativeExpense
2902 Collection agents Concept (Monetary) For Period Debit xcmig:CollectionExpenses
2903 Gain on disposal, Taesa Concept (Monetary) For Period Credit xcmig:GainLossOnDisposalOfShares
2904 Gain on disposal, Transchile Concept (Monetary) For Period Credit xcmig:GainLossOnDisposalsOfBusiness
2905 Loss on investment Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnDisposalsOfInvestments
2906 Other expenses Concept (Monetary) For Period Credit ifrs-full:OtherOperatingIncomeExpense
2907 Other operating expenses (revenues), net Concept (Monetary) For Period Credit xcmig:MiscellaneousOtherOperatingIncomeExpense
2908 1189 - Disclosure - Financial Revenues and Expenses - Summary of Financial Income and Expenses (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialRevenuesAndExpensesSummaryOfFinancialIncomeAndExpenses
2909 Implied Table Table

*

*

 implied:Table
2910 Disclosure of finance income expense [Abstract] Abstract xcmig:DisclosureOfFinanceIncomeExpenseAbstract
2911 FINANCE INCOME Abstract xcmig:FinancialRevenueAbstract
2912 Income from cash investments Concept (Monetary) For Period Credit xcmig:IncomeLossFromCashInvestments
2913 Arrears fees on sale of energy Concept (Monetary) For Period Credit xcmig:OutstandingChargesOnElectricityOverDueReceivable
2914 Foreign exchange variations Concept (Monetary) For Period Credit ifrs-full:NetForeignExchangeGain
2915 Monetary variations Concept (Monetary) For Period Credit xcmig:GainOnMonetaryVariations
2916 Monetary variations - CVA Concept (Monetary) For Period Credit xcmig:GainOnMonetaryVariationsCva
2917 Monetary updating on Court escrow deposits Concept (Monetary) For Period Credit xcmig:GainOnEscrowDeposit
2918 Pasep and Cofins charged on finance income Concept (Monetary) For Period Debit xcmig:TaxesChargedOnFinancialRevenues
2919 Other Concept (Monetary) For Period Credit ifrs-full:OtherFinanceIncome
2920 Finance income Concept (Monetary) For Period Credit ifrs-full:FinanceIncome
2921 FINANCE EXPENSES Abstract xcmig:FinancialExpensesAbstract
2922 Costs of loans and financings Concept (Monetary) For Period Debit xcmig:LoanAndFinancingCosts
2923 Cost of debt - amortization of transaction cost Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForAmountsTransferredToInitialCarryingAmountOfHedgedItems
2924 Foreign exchange variations Concept (Monetary) For Period Debit ifrs-full:NetForeignExchangeLoss
2925 Monetary updating - loans and financings Concept (Monetary) For Period Debit xcmig:LoansAndFinancingExpenseToBeIncreased
2926 Monetary updating - onerous concessions Concept (Monetary) For Period Debit xcmig:ConcessionAgreementsExpense
2927 Charges and monetary updating on post-retirement obligation Concept (Monetary) For Period Debit ifrs-full:PostemploymentBenefitExpenseDefinedContributionPlans
2928 Losses on financial instruments Concept (Monetary) For Period Debit ifrs-full:LossesOnDisposalsOfInvestments
2929 Monetary updating - CCEE obligations Concept (Monetary) For Period Debit xcmig:ExpenseOfElectricityTradingIncreased
2930 Monetary updating - CVA Concept (Monetary) For Period Debit xcmig:MonetaryUpdatingOnCva
2931 Monetary updating - AFAC Concept (Monetary) For Period Debit xcmig:MonetaryUpdatingOnAfac
2932 Monetary updating - Advance sales of power supply Concept (Monetary) For Period Debit xcmig:AdvanceSalesOfPowerSupply
2933 Adjustment to present value Concept (Monetary) For Period xcmig:AdjustmentsToFinancialExpensesPresentValue
2934 Other Concept (Monetary) For Period Debit ifrs-full:OtherFinanceCost
2935 Finance costs Concept (Monetary) For Period Debit ifrs-full:FinanceCosts
2936 NET FINANCE INCOME (EXPENSES) Concept (Monetary) For Period Credit ifrs-full:FinanceIncomeCost
2937 1190 - Disclosure - Related Party Transactions - Summary of Cemig's Principal Balances and Transactions With Related Parties (Detail) Network

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2938 Disclosure of transactions between related parties [table] Table

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*

 ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesTable
2939 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
2940 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
2941 Parent [member] Member ifrs-full:ParentMember
2942 Entities with joint control or significant influence over entity [member] Member ifrs-full:JointControlOrSignificantInfluenceMember
2943 Other related parties [member] Member ifrs-full:OtherRelatedPartiesMember
2944 Counterparties [axis] Axis ifrs-full:CounterpartiesAxis
2945 Counterparties [member] Member ifrs-full:CounterpartiesMember
2946 MINAS GERAIS STATE GOVT [member] Member xcmig:MinasGeraisStateGovtMember
2947 Alianca Geracao [member] Member xcmig:AliancaGeracaoMember
2948 Baguari Energia [member] Member xcmig:BaguariEnergiaMember
2949 Madeira Energia [member] Member xcmig:MadeiraEnergiaMember
2950 Norte Energia [member] Member xcmig:NorteEnergiaMember
2951 Lightger [member] Member xcmig:LightGerMember
2952 Hidreletrica Pipoca [member] Member xcmig:HidreletricaPipocaMember
2953 Retiro Baixo [member] Member xcmig:RetiroBaixoMember
2954 Guanhaes energia [member] Member xcmig:GuanhaesEnergiaMember
2955 Renova [member] Member xcmig:RenovaMember
2956 Empresa Amazonense de Transmissao de Energia EATE [member] Member xcmig:EmpresaAmazonenseDeTransmissaoDeEnergiaEateMember
2957 Light [member] Member xcmig:LightMember
2958 Taesa [member] Member xcmig:TaesaMember
2959 Cia. Transirape de Transmissao [member] Member xcmig:CiaTransirapeDeTransmissaoMember
2960 Axxiom [member] Member xcmig:AxxiomMember
2961 Transudeste [member] Member xcmig:TransudesteMember
2962 Transleste [member] Member xcmig:TranslesteMember
2963 FIC Pampulha [member] Member xcmig:FICPampulhaMember
2964 FORLUZ [member] Member xcmig:FORLUZMember
2965 CEMIG SAUDE [member] Member xcmig:CEMIGSAUDEMember
2966 Past due status [axis] Axis ifrs-full:PastDueStatusAxis
2967 Past due status [member] Member ifrs-full:PastDueStatusMember
2968 Current [member] Member ifrs-full:CurrentMember
2969 Non current [member] Member xcmig:NonCurrentMember
2970 Products and services [axis] Axis ifrs-full:ProductsAndServicesAxis
2971 Products and services [member] Member ifrs-full:ProductsAndServicesMember
2972 Consumers and traders [member] Member xcmig:ConsumersAndTradersMember
2973 Public Lighting Contribution [member] Member xcmig:PublicLightingContributionMember
2974 Accounts Receivable [member] Member xcmig:AccountsReceivable1Member
2975 Transactions in electricity [member] Member xcmig:TransactionsInElectricityMember
2976 Provision of services [member] Member xcmig:ProvisionOfServicesMember
2977 Interest on Equity, and dividends [member] Member xcmig:InterestOnEquityAndDividendsMember
2978 Services [Member] Member xcmig:ServicesMember
2979 Advance against future electricity supply [Member] Member xcmig:AdvanceAgainstFutureElectricitySupplyMember
2980 Advance for future power supply [member] Member xcmig:AdvanceForFuturePowerSupplyMember
2981 Adjustment for losses [member] Member xcmig:AdjustmentForLossesMember
2982 Advance for future delivery of power supply [member] Member xcmig:AdvanceForFutureDeliveryOfPowerSupplyMember
2983 Cash and cash equivalents [Member] Member xcmig:CashAndCashEquivalents1Member
2984 Securities [member] Member xcmig:SecuritiesMember
2985 Securities issued by subsidiary companies of Cemig [member] Member xcmig:SecuritiesIssuedBySubsidiaryCompaniesOfCemigMember
2986 Post-retirement obligations [member] Member xcmig:PostRetirementObligationsMember
2987 Supplementary pension contributions [member] Member xcmig:SupplementaryPensionContributionsMember
2988 Administrative running costs [member] Member xcmig:AdministrativeRunningCostsMember
2989 Operating leases [member] Member xcmig:OperatingLeasesMember
2990 Health and dental plans [member] Member xcmig:HealthAndDentalPlansMember
2991 Disclosure of transactions between related parties [line items] LineItems ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesLineItems
2992 Current assets Concept (Monetary) As Of Debit ifrs-full:CurrentAssets
2993 Non-current assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentAssets
2994 Current liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentLiabilities
2995 Non-current liabilities Concept (Monetary) As Of Credit ifrs-full:NoncurrentLiabilities
2996 Revenue Concept (Monetary) For Period Credit xcmig:RevenueFromRelatedParties1
2997 Expenses Concept (Monetary) For Period Debit xcmig:ExpenseForRelatedPartyTransactions
2998 1191 - Disclosure - Related Party Transactions - Summary of Cemig's Principal Balances and Transactions With Related Parties (Parenthetical) (Detail) Network

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2999 Disclosure of transactions between related parties [table] Table

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*

 ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesTable
3000 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
3001 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
3002 Renova [member] Member xcmig:RenovaMember
3003 Santo Antonio Energia [member] Member xcmig:SantoAntonioEnergiaMember
3004 Maturity [axis] Axis ifrs-full:MaturityAxis
3005 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
3006 Two Thousand and Eighteen [Member] Member xcmig:TwoThousandAndEighteenMember
3007 Two Thousand and Twenty [Member] Member xcmig:TwoThousandAndTwentyMember
3008 Two Thousand and Twenty One [Member] Member xcmig:TwoThousandAndTwentyOneMember
3009 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
3010 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
3011 Cemig GT [member] Member xcmig:CemigGTMember
3012 Sa Carvalho [member] Member xcmig:SaCarvalhoMember
3013 Rosal [Member] Member xcmig:RosalMember
3014 Non-adjusting events after reporting period [axis] Axis ifrs-full:NonadjustingEventsAfterReportingPeriodAxis
3015 Non-adjusting events after reporting period [member] Member ifrs-full:NonadjustingEventsMember
3016 Settlement agreement [member] Member xcmig:SettlementAgreementMember
3017 Disclosure of transactions between related parties [line items] LineItems ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesLineItems
3018 Due and unpaid payment of debits relating to supply of power Concept (Monetary) For Period Credit xcmig:RecognitionOfDebitsRelatingToSupplyOfPower
3019 Number of installments Concept (Integer) For Period xcmig:NumberOfMonthlyInstallments
3020 Amount paid for first installment Concept (Monetary) For Period Debit xcmig:ProceedsFromInstallmentPayment
3021 Advance payments Concept (Monetary) For Period Debit xcmig:AdvancePaymentsToRelatedParty
3022 Number of tranches Concept (Integer) For Period xcmig:NumberOfTranches
3023 Settlement amount receivables Concept (Monetary) As Of Credit xcmig:SettlementAmountReceivables
3024 Number of installments Concept (Integer) For Period xcmig:NumberOfMonthlyInstallments
3025 Percentage of settlement amount receivable Concept (Percent) For Period xcmig:PercentageOfSettlementAmountReceivable
3026 Percentage of settlement interest rate Concept (Percent) For Period xcmig:PercentageOfSettlementInterestRate
3027 Settlement amount initial payment Concept (Monetary) For Period Debit xcmig:ProceedsFromInitialPaymentOfSettlementReceivable
3028 1192 - Disclosure - Related Party Transactions - Summary of Cemig is Provider of Surety or Guarantee of Loans, Financings and Debentures of Related Parties (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureRelatedPartyTransactionsSummaryOfCemigIsProviderOfSuretyOrGuaranteeOfLoansFinancingsAndDebenturesOfRelatedParties
3029 Disclosure of transactions between related parties [table] Table

*

*

 ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesTable
3030 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
3031 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
3032 Norte Energia S.A [Member] Member xcmig:NorteEnergiaSAMember
3033 Light [member] Member xcmig:LightMember
3034 Santo Antnio Energia S.A. [Member] Member xcmig:SantoAntonioEnergiaSAMember
3035 Santo Antnio Energia S.A. One [Member] Member xcmig:SantoAntonioEnergiaSAOneMember
3036 Centroeste [member] Member xcmig:CentroesteMember
3037 Disclosure of transactions between related parties [line items] LineItems ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesLineItems
3038 Related party Concept (Text/String) For Period xcmig:NameOfRelatedParty
3039 Relationship Concept (Text/String) For Period ifrs-full:DescriptionOfNatureOfRelatedPartyRelationship
3040 Type Concept (Text/String) For Period xcmig:DescriptionOfTypeOfGuarantee
3041 Objective Concept (Text/String) For Period ifrs-full:DescriptionOfTransactionsWithRelatedParty
3042 Expiration Concept (Year) For Period xcmig:ExpirationYear
3043 Related party transaction amount Concept (Monetary) For Period Debit xcmig:RelatedPartyTransactionAmountsOfTransaction1
3044 1193 - Disclosure - Related Party Transactions - Summary of Financial Investments in Securities of Related Parties, in the Investment Fund (Detail) Network

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 http://imetrix.edgar-online.com/taxonomy/role/DisclosureRelatedPartyTransactionsSummaryOfFinancialInvestmentsInSecuritiesOfRelatedPartiesInTheInvestmentFund
3045 Investment [Table] Table

*

*

 invest:InvestmentTable
3046 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
3047 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
3048 Cemig [member] Member xcmig:CemigMember
3049 Cemig GT [member] Member xcmig:CemigGTMember
3050 Cemig D [member] Member xcmig:CemigDMember
3051 Other Subsidiaries [Member] Member xcmig:OtherSubsidiariesMember
3052 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
3053 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
3054 Related parties [member] Member ifrs-full:RelatedPartiesMember
3055 Investment Contract Counterparty [Axis] Axis invest:InvestmentContractCounterpartyAxis
3056 Investment Contract Counterparty [Domain] Member invest:InvestmentContractCounterpartyDomain
3057 ETAU [member] Member xcmig:ETAUMember
3058 Light [member] Member xcmig:LightMember
3059 Axxiom [member] Member xcmig:AxxiomMember
3060 Investment [Line Items] LineItems invest:InvestmentLineItems
3061 Type Concept (Text/String) For Period xcmig:DescriptionOfTypeOfSecurities
3062 Annual contractual conditions Concept (Text/String) For Period xcmig:DescriptionOfPercentageOfInvestmentsInRelatedParties
3063 Maturity Concept (Date) For Period invest:InvestmentMaturityDate1
3064 Number Of Investments Concept (Integer) For Period xcmig:NumberOfInvestmentUnits
3065 1194 - Disclosure - Related Party Transactions - Summary of Financial Investments in Securities of Related Parties, in the Investment Fund (Parenthetical) (Detail) Network

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 http://imetrix.edgar-online.com/taxonomy/role/DisclosureRelatedPartyTransactionsSummaryOfFinancialInvestmentsInSecuritiesOfRelatedPartiesInTheInvestmentFundParenthetical
3066 Investment [Table] Table

*

*

 invest:InvestmentTable
3067 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
3068 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
3069 Related parties [member] Member ifrs-full:RelatedPartiesMember
3070 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
3071 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
3072 Cemig [member] Member xcmig:CemigMember
3073 Cemig GT [member] Member xcmig:CemigGTMember
3074 Cemig D [member] Member xcmig:CemigDMember
3075 Other Subsidiaries [Member] Member xcmig:OtherSubsidiariesMember
3076 Investment [Line Items] LineItems invest:InvestmentLineItems
3077 Percentage of investment Concept (Percent) For Period xcmig:PercentageOfInvestments
3078 1195 - Disclosure - Related Party transactions - Summary of Total Costs of Key Management Personnel (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureRelatedPartyTransactionsSummaryOfTotalCostsOfKeyManagementPersonnel
3079 Implied Table Table

*

*

 implied:Table
3080 Disclosure of key management personnel compensation [abstract] Abstract xcmig:DisclosureOfKeyManagementPersonnelCompensationAbstract
3081 Remuneration Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensation
3082 Profit sharing (reversal) Concept (Monetary) For Period Debit xcmig:KeyManagementPersonnelProfitSharesReversals
3083 Assistance benefits Concept (Monetary) For Period Debit xcmig:KeyManagementPersonnelAssistanceBenefits
3084 Total Concept (Monetary) For Period Debit xcmig:KeyManagementPersonnelCompensationSalariesAndOtherBenefits
3085 1196 - Disclosure - Financial Instruments and Risk Management - Additional Information (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementAdditionalInformation
3086 Disclosure Of Financial Instruments And Financial Risk Management [Table] Table

*

*

 xcmig:DisclosureOfFinancialInstrumentsAndFinancialRiskManagementTable
3087 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
3088 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
3089 Parent [member] Member ifrs-full:ParentMember
3090 Individual company [Member] Member xcmig:IndividualCompanyMember
3091 Levels of fair value hierarchy [axis] Axis ifrs-full:LevelsOfFairValueHierarchyAxis
3092 All levels of fair value hierarchy [member] Member ifrs-full:AllLevelsOfFairValueHierarchyMember
3093 Level 2 [member] Member ifrs-full:Level2OfFairValueHierarchyMember
3094 Legal Entity [Axis] Axis dei:LegalEntityAxis
3095 Entity [Domain] Member dei:EntityDomain
3096 Lepsa [member] Member xcmig:LepsaMember
3097 RME [member] Member xcmig:RmeMember
3098 Cemig Telecom [member] Member xcmig:CemigTelecomMember
3099 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
3100 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
3101 Ordinary shares [member] Member ifrs-full:OrdinarySharesMember
3102 Preference shares [member] Member ifrs-full:PreferenceSharesMember
3103 Currency [Axis] Axis us-gaap:CurrencyAxis
3104 All Currencies [Domain] Member currency:AllCurrenciesDomain
3105 US dollar [member] Member currency:USD
3106 Euro [member] Member currency:EUR
3107 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
3108 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
3109 Selic rate [member] Member xcmig:SelicRateMember
3110 TJLP [member] Member xcmig:TJLPMember
3111 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
3112 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
3113 Transmissora Alianca de Energia Eletrica S.A. [member] Member xcmig:TransmissoraAliancadeEnergiaEletricaSAMember
3114 Light SA [member] Member xcmig:LightSAMember
3115 Types of risks [axis] Axis ifrs-full:TypesOfRisksAxis
3116 Risks [member] Member ifrs-full:TypesOfRisksMember
3117 Credit Risk [Member] Member ifrs-full:CreditRiskMember
3118 Continuing involvement in derecognised financial assets by type of instrument [axis] Axis ifrs-full:ContinuingInvolvementInDerecognisedFinancialAssetsByTypeOfInstrumentAxis
3119 Types of instrument [member] Member ifrs-full:TypesOfInstrumentMember
3120 Put option [Member] Member ifrs-full:WrittenPutOptionsMember
3121 Put options for shares in Parati [Member] Member xcmig:PutOptionsForSharesInParatiMember
3122 Classes of financial instruments [axis] Axis ifrs-full:ClassesOfFinancialInstrumentsAxis
3123 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
3124 Put option - SAAG [member] Member xcmig:PutOptionSAAGMember
3125 Classes of financial assets [axis] Axis ifrs-full:ClassesOfFinancialAssetsAxis
3126 Financial assets, class [member] Member ifrs-full:FinancialAssetsMember
3127 Certificado De Deposito Interbancario [Member] Member xcmig:CertificadoDeDepositoInterbancarioMember
3128 Range [axis] Axis ifrs-full:RangeAxis
3129 Ranges [member] Member ifrs-full:RangesMember
3130 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
3131 Top of range [member] Member ifrs-full:TopOfRangeMember
3132 Non-adjusting events after reporting period [axis] Axis ifrs-full:NonadjustingEventsAfterReportingPeriodAxis
3133 Non-adjusting events after reporting period [member] Member ifrs-full:NonadjustingEventsMember
3134 Events After Reporting Period [Member] Member xcmig:EventsAfterReportingPeriodMember
3135 Probable scenario 2 [Member] Member xcmig:ScenarioTwoMember
3136 Scenario 3 [member] Member xcmig:ScenarioThreeMember
3137 Types of interest rates [axis] Axis ifrs-full:TypesOfInterestRatesAxis
3138 Interest rate types [member] Member ifrs-full:InterestRateTypesMember
3139 IPCA [Member] Member xcmig:IPCAMember
3140 Disclosure Of Financial Instruments And Financial Risk Managements [Line Items] LineItems xcmig:DisclosureOfFinancialInstrumentsAndFinancialRiskManagementsLineItems
3141 Securities held for trading Concept (Monetary) As Of Credit xcmig:SecuritiesHeldForTrading
3142 Financial instruments held to maturity Concept (Monetary) As Of Debit ifrs-full:HeldtomaturityInvestments
3143 Calculation of percentage of loans and debentures Concept (Percent) For Period xcmig:CalculationPercentageOfLoansFairValue
3144 Description of annual rates loans and debentures Concept (Text/String) For Period xcmig:DescriptionOfAnnualRatesOfLoansAndDebentures
3145 Loans, financings and debentures Concept (Monetary) As Of Credit ifrs-full:Borrowings
3146 Exercise price of financial remuneration percentage Concept (Percent) For Period xcmig:ExercisePriceOfFinancialRemunerationPercentage
3147 Liability Concept (Monetary) As Of Credit ifrs-full:NoncurrentDerivativeFinancialLiabilities
3148 Risk-free interest rate Concept (Percent) For Period xcmig:RiskFreeInterestRate
3149 Volatility Concept (Percent) For Period xcmig:FinancialInstrumentsVolatilityRate
3150 Put option, price Concept (Monetary) As Of Credit xcmig:PutOption
3151 Description of terms of shares reserved for issue under options and contracts for sale of shares Concept (Text/String) For Period ifrs-full:DescriptionOfTermsOfSharesReservedForIssueUnderOptionsAndContractsForSaleOfShares
3152 Number of shares held by associates Concept (Shares) As Of ifrs-full:SharesInEntityHeldByEntityOrByItsSubsidiariesOrAssociates
3153 Percentage of preferred shares Concept (Percent) As Of xcmig:PercentageOfPreferredSharesInShareCapital
3154 Preferred shares Concept (Shares) As Of ifrs-full:NumberOfSharesIssued
3155 Percentage of share of put option divided among partners Concept (Percent) For Period xcmig:PercentageOfShareOfPutOptionDividedAmongPartners
3156 Cash paid for exercise of put option Concept (Monetary) For Period Debit xcmig:CashPaidForExerciseOfPutOption
3157 Number of shares reserved for issue under options Concept (Shares) As Of ifrs-full:SharesReservedForIssueUnderOptionsAndContractsForSaleOfShares
3158 Exercise price of put option as number of times adjusted net profit Concept (Decimal) For Period xcmig:ExercisePriceOfPutOptionAsNumberOfTimesAdjustedNetProfit
3159 Exercise price of call option as number of times adjusted net profit Concept (Decimal) For Period xcmig:ExercisePriceOfCallOptionAsNumberOfTimesAdjustedNetProfit
3160 Option vesting date Concept (Date) For Period xcmig:OptionVestingDate
3161 Net effect of call and put options Concept (Monetary) For Period Credit ifrs-full:GainLossOnHedgeIneffectivenessRecognisedInProfitOrLoss
3162 Non cash negative adjustment from derivative transaction Concept (Monetary) For Period Debit xcmig:NonCashNegativeAdjustmentFromDerivativeTransaction
3163 Percentage of increase in US dollars Concept (Percent) As Of xcmig:PercentageOfIncreaseInUnitedStatesDollar
3164 Exchange rate Concept (Decimal) For Period ifrs-full:AverageForeignExchangeRate
3165 Percentage of increase in euro Concept (Percent) For Period xcmig:PercentageOfIncreaseInEuro
3166 Percentage of depreciation from real exchange rate Concept (Percent) As Of xcmig:PercentageOfDepreciationFromRealExchangeRate
3167 Borrowings interest rate Concept (Percent) As Of ifrs-full:BorrowingsInterestRate
3168 Increase in interest rate Concept (Percent) For Period xcmig:PercentageOfIncreaseInInterestRate
3169 Actuarial assumption of expected rates of inflation Concept (Percent) As Of ifrs-full:ActuarialAssumptionOfExpectedRatesOfInflation
3170 Increase in inflation rate Concept (Percent) For Period xcmig:IncreaseInInflationRate
3171 Cash flow projection period Concept (xbrli:durationItemType) For Period xcmig:CashFlowProjectionPeriod
3172 Daily liquidity projection period Concept (xbrli:durationItemType) For Period xcmig:DailyLiquidityProjectionPeriod
3173 Allowance for doubtful debtors Concept (Monetary) As Of Credit ifrs-full:AllowanceAccountForCreditLossesOfFinancialAssets
3174 Number of risk rating agencies used Concept (Integer) For Period xcmig:NumberOfRiskRatingAgencies
3175 Equity Concept (Monetary) As Of Credit ifrs-full:Equity
3176 Basel ratio Concept (Percent) For Period xcmig:BaselRatio
3177 Portfolio percentage of individual Concept (Percent) For Period xcmig:ConcentrationRisksPercentage
3178 1197 - Disclosure - Financial Instruments and Risk Management - Summary of Put Option (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementSummaryOfPutOption
3179 Disclosure of detailed information about financial instruments [table] Table

*

*

 ifrs-full:DisclosureOfFinancialInstrumentsTable
3180 Classes of financial instruments [axis] Axis ifrs-full:ClassesOfFinancialInstrumentsAxis
3181 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
3182 Put option for shares in RME and Lepsa [member] Member xcmig:PutOptionForSharesInRmeAndLepsaMember
3183 Put option - SAAG [member] Member xcmig:PutOptionSAAGMember
3184 Put / call options - Ativas and Sonda [member] Member xcmig:PutCallOptionsAtivasAndSondaMember
3185 Continuing involvement in derecognised financial assets by type of instrument [axis] Axis ifrs-full:ContinuingInvolvementInDerecognisedFinancialAssetsByTypeOfInstrumentAxis
3186 Types of instrument [member] Member ifrs-full:TypesOfInstrumentMember
3187 Put Option 1 [member] Member xcmig:PutOption1Member
3188 Disclosure of detailed information about financial instruments [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsLineItems
3189 Put option Concept (Monetary) As Of Debit xcmig:DerivativeFinancialInstruments
3190 1198 - Disclosure - Financial Instruments and Risk Management - Summary of Put Option (Parenthetical) (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementSummaryOfPutOptionParenthetical
3191 Disclosure of detailed information about financial instruments [table] Table

*

*

 ifrs-full:DisclosureOfFinancialInstrumentsTable
3192 Classes of financial instruments [axis] Axis ifrs-full:ClassesOfFinancialInstrumentsAxis
3193 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
3194 Put option for shares in RME and Lepsa [member] Member xcmig:PutOptionForSharesInRmeAndLepsaMember
3195 Disclosure of detailed information about financial instruments [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsLineItems
3196 Equity interest Concept (Percent) For Period ifrs-full:ProportionOfVotingPowerHeldInSubsidiary
3197 1199 - Disclosure - Financial Instruments and Risk Management - Summary of Changes in Value of Options (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementSummaryOfChangesInValueOfOptions
3198 Disclosure of financial liabilities [table] Table

*

*

 ifrs-full:DisclosureOfFinancialLiabilitiesTable
3199 Classes of financial instruments [axis] Axis ifrs-full:ClassesOfFinancialInstrumentsAxis
3200 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
3201 Put option - SAAG [member] Member xcmig:PutOptionSAAGMember
3202 Disclosure of financial liabilities [line items] LineItems ifrs-full:DisclosureOfFinancialLiabilitiesLineItems
3203 Balance Concept (Monetary) As Of Credit ifrs-full:DerivativeFinancialLiabilities
3204 Variation in fair value Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseInFairValueMeasurementLiabilities
3205 Adjustment to fair value Concept (Monetary) For Period Credit xcmig:AdjustmentToFairValueOfOptions
3206 Reversals Concept (Monetary) For Period Debit xcmig:ReversalsDerivativeFinancialLiabilities
3207 Balance Concept (Monetary) As Of Credit ifrs-full:DerivativeFinancialLiabilities
3208 1200 - Disclosure - Financial Instruments and Risk Management - Summary of Changes in Value of Options - The Difference Between Esimated Fair Value for Assets and Corresponding Exercise Price (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementSummaryOfChangesInValueOfOptionsTheDifferenceBetweenEsimatedFairValueForAssetsAndCorrespondingExercisePrice
3209 Implied Table Table

*

*

 implied:Table
3210 Disclosure of financial liabilities [abstract] Abstract ifrs-full:DisclosureOfFinancialLiabilitiesAbstract
3211 Balance Concept (Monetary) As Of xcmig:OptionsOutstandingGrantDateFairValue
3212 Variation in fair value Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseInFairValueMeasurementLiabilities
3213 Variation in fair value Concept (Monetary) For Period Debit xcmig:IncreaseDecreaseInValuationInFairValueOfOptions
3214 Written down, due to exercise of Put Concept (Monetary) For Period Debit xcmig:WrittenDownDueToExerciseOfPutInFairValueOfOptions
3215 Reversals Concept (Monetary) For Period Debit xcmig:ReversalsInFairValueOfOptions
3216 Balance Concept (Monetary) As Of xcmig:OptionsOutstandingGrantDateFairValue
3217 1201 - Disclosure - Financial Instruments and Risk Management - Summary of Derivative Instruments Contracted (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementSummaryOfDerivativeInstrumentsContracted
3218 Implied Table Table

*

*

 implied:Table
3219 Derivative financial instruments [Abstract] Abstract xcmig:DerivativeFinancialInstrumentsAbstract
3220 emig's right Concept (Text/String) For Period xcmig:RightToCallDescription
3221 Cemig's obligatio Concept (Text/String) For Period xcmig:DescriptionOfObligationOnBorrowings
3222 n Maturity period Concept (Text/String) For Period xcmig:FinancialInstrumentsMaturityPeriod
3223 principal racted Concept (Monetary) For Period Debit xcmig:ValueOfPrincipalContracted
3224 Unrealized ga Amount according to contract 2017 Concept (Monetary) For Period Debit xcmig:UnrealizedGainLossAccordingToContract
3225 in /loss Fair value 2017 Concept (Monetary) For Period Debit xcmig:UnrealizedGainLossFairValue
3226 1202 - Disclosure - Financial Instruments and Risk Management - Summary of Derivative Instruments Contracted (Parenthetical) (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementSummaryOfDerivativeInstrumentsContractedParenthetical
3227 Implied Table Table

*

*

 implied:Table
3228 Derivative financial instruments [Abstract] Abstract xcmig:DerivativeFinancialInstrumentsAbstract
3229 Swap operation floor rate Concept (Monetary) For Period xcmig:SwapOperationFloorRate
3230 Swap ceiling rate Concept (Monetary) For Period xcmig:SwapCeilingRate
3231 FX Variation Interest rate Concept (Percent) For Period xcmig:FXVariationInterestRate
3232 1203 - Disclosure - Financial Instruments and Risk Management - Summary of Exposure to Exchange Rates (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementSummaryOfExposureToExchangeRates
3233 Disclosure of risk management strategy related to hedge accounting [table] Table

*

*

 ifrs-full:DisclosureOfRiskManagementStrategyRelatedToHedgeAccountingTable
3234 Categories of financial liabilities [axis] Axis ifrs-full:CategoriesOfFinancialLiabilitiesAxis
3235 Financial liabilities, category [member] Member ifrs-full:FinancialLiabilitiesCategoryMember
3236 Loans and Financings [member] Member xcmig:LoansAndFinancingsMember
3237 Currency [Axis] Axis us-gaap:CurrencyAxis
3238 All Currencies [Domain] Member currency:AllCurrenciesDomain
3239 US dollar [member] Member currency:USD
3240 Euro [member] Member currency:EUR
3241 Foreign currency risk [member] Member xcmig:ForeignCurrencyRiskMember
3242 Counterparties [axis] Axis ifrs-full:CounterpartiesAxis
3243 Counterparties [member] Member ifrs-full:CounterpartiesMember
3244 Supply From Itaipu Binacional [member] Member xcmig:ItaipuBinacionalMember
3245 Types of risks [axis] Axis ifrs-full:TypesOfRisksAxis
3246 Risks [member] Member ifrs-full:TypesOfRisksMember
3247 Foreign currency risk [member] Member xcmig:ForeignCurrencyRiskMember
3248 Disclosure of risk management strategy related to hedge accounting [line items] LineItems ifrs-full:DisclosureOfRiskManagementStrategyRelatedToHedgeAccountingLineItems
3249 Net liabilities exposed Concept (Monetary) As Of Credit xcmig:NetLiabilityExposureValue
3250 1204 - Disclosure - Financial Instruments and Risk Management - Schedule of Exposure to Exchange Rates (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementScheduleOfExposureToExchangeRates
3251 Disclosure of risk management strategy related to hedge accounting [table] Table

*

*

 ifrs-full:DisclosureOfRiskManagementStrategyRelatedToHedgeAccountingTable
3252 Range [axis] Axis ifrs-full:RangeAxis
3253 Ranges [member] Member ifrs-full:RangesMember
3254 Base cenario [member] Member xcmig:ScenarioMember
3255 Probable Scenario [Member] Member xcmig:ProbableScenarioMember
3256 Possible Scenario [member] Member xcmig:PossibleScenarioMember
3257 Remote Scenario [member] Member xcmig:RemoteScenarioMember
3258 Foreign Currencies Used for Translations [axis] Axis xcmig:ForeignCurrenciesUsedForTranslationsAxis
3259 Foreign Currencies Used For Translations [Domain] Member xcmig:ForeignCurrenciesUsedForTranslationsDomain
3260 Three Point Four One One Brazil Real Per US Dollar [Member] Member xcmig:ThreePointFourOneOneBrazilRealPerUsDollarMember
3261 Four Point Two Six Four Brazil Real Per US Dollar [Member] Member xcmig:FourPointTwoSixFourBrazilRealPerUsDollarMember
3262 Five Point One One Seven Brazil Real Per US Dollar [Member] Member xcmig:FivePointOneOneSevenBrazilRealPerUsDollarMember
3263 Exchange rate depreciation [Axis] Axis xcmig:ExchangeRateDepreciationAxis
3264 Exchange rate depreciation [Member] Member xcmig:ExchangeRateDepreciationMember
3265 Depreciation of twenty five percentage on brazil real [member] Member xcmig:DepreciationOfTwentyFivePercentageOnBrazilRealMember
3266 Depreciation of fifty percentage on brazil real [member] Member xcmig:DepreciationOfFiftyPercentageOnBrazilRealMember
3267 Categories of financial liabilities [axis] Axis ifrs-full:CategoriesOfFinancialLiabilitiesAxis
3268 Financial liabilities, category [member] Member ifrs-full:FinancialLiabilitiesCategoryMember
3269 Loans and Financings [member] Member xcmig:LoansAndFinancingsMember
3270 Counterparties [axis] Axis ifrs-full:CounterpartiesAxis
3271 Counterparties [member] Member ifrs-full:CounterpartiesMember
3272 Supply From Itaipu Binacional [member] Member xcmig:ItaipuBinacionalMember
3273 Disclosure of risk management strategy related to hedge accounting [line items] LineItems ifrs-full:DisclosureOfRiskManagementStrategyRelatedToHedgeAccountingLineItems
3274 Loans and financings (Note 20) Concept (Monetary) As Of Credit xcmig:NetLiabilityExposureValue
3275 Net effect of exchange rate variation Concept (Monetary) As Of Credit xcmig:EffectOnExchangeRateVariation
3276 1205 - Disclosure - Financial Instruments and Risk Management - Summary of Exposed Interest Rate Risk (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementSummaryOfExposedInterestRateRisk
3277 Disclosure of financial instruments by type of interest rate [table] Table

*

*

 ifrs-full:DisclosureOfFinancialInstrumentsByTypeOfInterestRateTable
3278 Currency [Axis] Axis us-gaap:CurrencyAxis
3279 All Currencies [Domain] Member currency:AllCurrenciesDomain
3280 Domestic currency [member] Member xcmig:DomesticCurrencyMember
3281 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
3282 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
3283 Renova [member] Member xcmig:RenovaMember
3284 Products and services [axis] Axis ifrs-full:ProductsAndServicesAxis
3285 Products and services [member] Member ifrs-full:ProductsAndServicesMember
3286 Advance for future delivery of power supply [member] Member xcmig:AdvanceForFutureDeliveryOfPowerSupplyMember
3287 Advance For Future Delivery Of Energy Supply [Member] Member xcmig:AdvanceForFutureDeliveryOfEnergySupplyMember
3288 Types of interest rates [axis] Axis ifrs-full:TypesOfInterestRatesAxis
3289 Interest rate types [member] Member ifrs-full:InterestRateTypesMember
3290 Selic rate [member] Member xcmig:SelicRateMember
3291 Eletrobras [member] Member xcmig:EletrobrasMember
3292 CDI rate[member] Member xcmig:CdiRateMember
3293 TJLP [member] Member xcmig:TJLPMember
3294 Disclosure of financial instruments by type of interest rate [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsByTypeOfInterestRateLineItems
3295 Assets Abstract ifrs-full:AssetsAbstract
3296 Cash equivalents - Cash investments (Note 6) Concept (Monetary) As Of Debit ifrs-full:ShorttermInvestmentsClassifiedAsCashEquivalents
3297 Securities (Note 7) Concept (Monetary) As Of Debit xcmig:ShortTermAndLongTermSecurities
3298 Accounts receivable - Renova (Note 29) Concept (Monetary) As Of Debit ifrs-full:AmountsReceivableRelatedPartyTransactions
3299 Advance for future delivery of energy supply Concept (Monetary) As Of Debit ifrs-full:CurrentAssets
3300 Receivable for residual value - Generation - SELIC (Note 15) Concept (Monetary) As Of Debit xcmig:ReceivableForResidualValue
3301 Restricted cash Concept (Monetary) As Of Debit ifrs-full:RestrictedCashAndCashEquivalents
3302 CVA and in tariffs - Selic rate * (Note 15) Concept (Monetary) As Of Debit ifrs-full:FinancialAssets
3303 Credits owed by Eletrobras Concept (Monetary) As Of Credit xcmig:CreditsInInterestRateRisk
3304 Total assets Concept (Monetary) As Of Debit ifrs-full:Assets
3305 Liabilities Abstract ifrs-full:LiabilitiesAbstract
3306 Loans, financings and debentures - CDI rate (Note 21) Concept (Monetary) As Of Credit ifrs-full:Borrowings
3307 Advance sales of energy supply - CDI (Note 8) Concept (Monetary) As Of Credit ifrs-full:CurrentLiabilities
3308 CVA and Other Financial components in tariffs (Note 15) Concept (Monetary) As Of Credit ifrs-full:FinancialLiabilities
3309 Adherence to the Tax Anmesty Program (PRCT) (Note 20) Concept (Monetary) For Period Credit xcmig:AdherenceToTheTaxAnmestyProgram
3310 Liabilities Concept (Monetary) As Of Credit ifrs-full:Liabilities
3311 Net liabilities exposed Concept (Monetary) As Of Debit ifrs-full:NetAssetsLiabilities
3312 1206 - Disclosure - Financial Instruments and Risk Management - Estimation of Company Interest Rate (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementEstimationOfCompanyInterestRate
3313 Disclosure of financial instruments by type of interest rate [table] Table

*

*

 ifrs-full:DisclosureOfFinancialInstrumentsByTypeOfInterestRateTable
3314 Types of risks [axis] Axis ifrs-full:TypesOfRisksAxis
3315 Risks [member] Member ifrs-full:TypesOfRisksMember
3316 Interest rate risk [member] Member ifrs-full:InterestRateRiskMember
3317 Measurement [axis] Axis ifrs-full:MeasurementAxis
3318 Aggregated measurement [member] Member ifrs-full:AggregatedMeasurementMember
3319 Book value [member] Member ifrs-full:AtCostMember
3320 Non-adjusting events after reporting period [axis] Axis ifrs-full:NonadjustingEventsAfterReportingPeriodAxis
3321 Non-adjusting events after reporting period [member] Member ifrs-full:NonadjustingEventsMember
3322 Probable scenario 1 [member] Member xcmig:ScenarioOneMember
3323 Probable scenario 2 [Member] Member xcmig:ScenarioTwoMember
3324 Scenario 3 [member] Member xcmig:ScenarioThreeMember
3325 Products and services [axis] Axis ifrs-full:ProductsAndServicesAxis
3326 Products and services [member] Member ifrs-full:ProductsAndServicesMember
3327 Advance For Future Delivery Of Energy Supply [Member] Member xcmig:AdvanceForFutureDeliveryOfEnergySupplyMember
3328 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
3329 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
3330 Renova [member] Member xcmig:RenovaMember
3331 Types of interest rates [axis] Axis ifrs-full:TypesOfInterestRatesAxis
3332 Interest rate types [member] Member ifrs-full:InterestRateTypesMember
3333 Selic rate [member] Member xcmig:SelicRateMember
3334 CDI rate[member] Member xcmig:CdiRateMember
3335 TJLP [member] Member xcmig:TJLPMember
3336 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
3337 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
3338 Selic rate [member] Member xcmig:SelicRateMember
3339 Eletrobras [member] Member xcmig:EletrobrasMember
3340 Disclosure of financial instruments by type of interest rate [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsByTypeOfInterestRateLineItems
3341 Assets Abstract ifrs-full:AssetsAbstract
3342 Short-term investments Concept (Monetary) As Of Debit ifrs-full:ShorttermInvestmentsClassifiedAsCashEquivalents
3343 Securities Concept (Monetary) As Of Debit xcmig:ShortTermAndLongTermSecurities
3344 Accounts receivable - Renova (Note 29) Concept (Monetary) As Of Debit ifrs-full:AmountsReceivableRelatedPartyTransactions
3345 Advance for future delivery of energy supply Concept (Monetary) As Of Debit ifrs-full:CurrentAssets
3346 Receivable for residual value - Generation - SELIC (Note 15) Concept (Monetary) As Of Debit xcmig:ReceivableForResidualValue
3347 Restricted cash Concept (Monetary) As Of Debit ifrs-full:RestrictedCashAndCashEquivalents
3348 CVA and Other financial components in tariff adjustments - Selic rate Concept (Monetary) As Of Debit ifrs-full:FinancialAssets
3349 Credits owed by Eletrobras Concept (Monetary) As Of Credit xcmig:CreditsInInterestRateRisk
3350 Total assets Concept (Monetary) As Of Debit ifrs-full:Assets
3351 Liabilities Abstract ifrs-full:LiabilitiesAbstract
3352 Loans and financings - CDI (Note 21) Concept (Monetary) As Of Credit ifrs-full:Borrowings
3353 Advance sales of energy supply-CDI (Note 8) Concept (Monetary) As Of Credit ifrs-full:CurrentLiabilities
3354 CVA and Other Financial components in tariffs (Note 15) Concept (Monetary) As Of Credit ifrs-full:FinancialLiabilities
3355 Adherence to Tax Anmesty Program (PRCT) (Note 20) Concept (Monetary) For Period Credit xcmig:AdherenceToTheTaxAnmestyProgram
3356 Liabilities Concept (Monetary) As Of Credit ifrs-full:Liabilities
3357 Net assets (liabilities) exposed Concept (Monetary) As Of Debit ifrs-full:NetAssetsLiabilities
3358 Net effect of variation in interest rates Concept (Monetary) As Of Debit xcmig:NetEffectOfChangeInInterestRate
3359 1207 - Disclosure - Financial Instruments and Risk Management - Summary of Risk of Increase in Inflation (Detail) Network

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*

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3360 Disclosure of assets and liabilities with significant risk of material adjustment [table] Table

*

*

 ifrs-full:DisclosureOfAssetsAndLiabilitiesWithSignificantRiskOfMaterialAdjustmentTable
3361 Types of risks [axis] Axis ifrs-full:TypesOfRisksAxis
3362 Risks [member] Member ifrs-full:TypesOfRisksMember
3363 Interest rate risk [member] Member ifrs-full:InterestRateRiskMember
3364 Service concession arrangements [axis] Axis ifrs-full:ServiceConcessionArrangementsAxis
3365 Service concession arrangements [member] Member ifrs-full:ServiceConcessionArrangementsMember
3366 Infrastructure -Distribution [Member] Member xcmig:InfrastructureDistributionMember
3367 Transmission Indemnity receivable [member] Member xcmig:TransmissionIndemnityReceivableMember
3368 Concession Grant Fee [Member] Member xcmig:ConcessionGrantFeeMember
3369 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
3370 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
3371 Loans, financings and debentures [member] Member xcmig:LoansFinancingsAndDebenturesMember
3372 Debt agreed with pension fund [Member] Member xcmig:DebtAgreedWithPensionFundMember
3373 Forluz deficit of pension plan [member] Member xcmig:ForluzDeficitOfPensionPlanMember
3374 Disclosure of assets and liabilities with significant risk of material adjustment [line items] LineItems ifrs-full:DisclosureOfAssetsAndLiabilitiesWithSignificantRiskOfMaterialAdjustmentLineItems
3375 Financial assets Concept (Monetary) As Of Debit ifrs-full:FinancialAssets
3376 Financial liabilities Concept (Monetary) As Of Credit ifrs-full:FinancialLiabilities
3377 Net assets (liabilities) exposed Concept (Monetary) As Of Debit xcmig:NetAssetsLiabilitiesExposedToInflationRates
3378 1208 - Disclosure - Financial Instruments and Risk Management - Summary of Risk of Increase in Inflation Sensitive Analysis (Detail) Network

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*

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3379 Disclosure of assets and liabilities with significant risk of material adjustment [table] Table

*

*

 ifrs-full:DisclosureOfAssetsAndLiabilitiesWithSignificantRiskOfMaterialAdjustmentTable
3380 Measurement [axis] Axis ifrs-full:MeasurementAxis
3381 Aggregated measurement [member] Member ifrs-full:AggregatedMeasurementMember
3382 Book value [member] Member ifrs-full:AtCostMember
3383 Non-adjusting events after reporting period [axis] Axis ifrs-full:NonadjustingEventsAfterReportingPeriodAxis
3384 Non-adjusting events after reporting period [member] Member ifrs-full:NonadjustingEventsMember
3385 Probable Scenario [Member] Member xcmig:ProbableScenarioMember
3386 Possible Scenario [member] Member xcmig:PossibleScenarioMember
3387 Remote Scenario [member] Member xcmig:RemoteScenarioMember
3388 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
3389 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
3390 Infrastructure -Distribution [Member] Member xcmig:InfrastructureDistributionMember
3391 Transmission Indemnity receivable [member] Member xcmig:TransmissionIndemnityReceivableMember
3392 Concession Grant Fee [Member] Member xcmig:ConcessionGrantFeeMember
3393 Types of interest rates [axis] Axis ifrs-full:TypesOfInterestRatesAxis
3394 Interest rate types [member] Member ifrs-full:InterestRateTypesMember
3395 Loans, financings and debentures [member] Member xcmig:LoansFinancingsAndDebenturesMember
3396 Debt agreed with pension fund [Member] Member xcmig:DebtAgreedWithPensionFundMember
3397 Forluz deficit of pension plan [member] Member xcmig:ForluzDeficitOfPensionPlanMember
3398 IPCA [Member] Member xcmig:IPCAMember
3399 Disclosure of assets and liabilities with significant risk of material adjustment [line items] LineItems ifrs-full:DisclosureOfAssetsAndLiabilitiesWithSignificantRiskOfMaterialAdjustmentLineItems
3400 Financial assets Concept (Monetary) As Of Debit ifrs-full:FinancialAssets
3401 Financial liabilities Concept (Monetary) As Of Credit ifrs-full:FinancialLiabilities
3402 Net assets (liabilities) exposed Concept (Monetary) As Of Debit ifrs-full:NetAssetsLiabilities
3403 Net effect of variation in IPCA and IGP-M indices Concept (Monetary) As Of Credit xcmig:EffectOfVariationInInflationRates
3404 1209 - Disclosure - Financial Instruments and Risk Management - Summary of Flow of Payments of the Company's Obligations for Debt Agreed, Financings and Debentures for Floating and Fixed Rates Including the Interest Specified in Contracts (Detail) Network

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3405 Disclosure of financial instruments by type of interest rate [table] Table

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*

 ifrs-full:DisclosureOfFinancialInstrumentsByTypeOfInterestRateTable
3406 Maturity [axis] Axis ifrs-full:MaturityAxis
3407 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
3408 Up to 1 month [Member] Member ifrs-full:NotLaterThanOneMonthMember
3409 1 to 3 months [Member] Member ifrs-full:LaterThanOneMonthAndNotLaterThanThreeMonthsMember
3410 3 months to 1 year [Member] Member ifrs-full:LaterThanThreeMonthsAndNotLaterThanOneYearMember
3411 1 to 5 years [Member] Member ifrs-full:LaterThanOneYearAndNotLaterThanFiveYearsMember
3412 Over 5 years [Member] Member ifrs-full:LaterThanFiveYearsMember
3413 Types of interest rates [axis] Axis ifrs-full:TypesOfInterestRatesAxis
3414 Interest rate types [member] Member ifrs-full:InterestRateTypesMember
3415 Floating rates [member] Member ifrs-full:FloatingInterestRateMember
3416 Fixed rate [member] Member ifrs-full:FixedInterestRateMember
3417 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
3418 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
3419 Loans, financings and debentures [member] Member xcmig:LoansFinancingsAndDebenturesMember
3420 Tax Anmesty Program (PRCT) [member] Member xcmig:TaxAnmestyProgramMember
3421 Onerous concessions [member] Member xcmig:OnerousConcessionsMember
3422 Debt agreed with pension plan (Forluz) [member] Member xcmig:DebtAgreedWithPensionPlanMember
3423 Solution plan for deficit of the pensio plan (Forluz) [member] Member xcmig:SolutionPlanForDeficitOfThePensionPlanMember
3424 Suppliers [Member] Member xcmig:SuppliersMember
3425 Disclosure of financial instruments by type of interest rate [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsByTypeOfInterestRateLineItems
3426 Financial assets held for managing liquidity risk Concept (Monetary) As Of Debit ifrs-full:FinancialAssetsHeldForManagingLiquidityRisk
3427 1210 - Disclosure - Financial Instruments and Risk Management - Summary of Credit Exposure (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementSummaryOfCreditExposure
3428 Disclosure of credit risk exposure [table] Table

*

*

 ifrs-full:DisclosureOfCreditRiskExposureTable
3429 Range [axis] Axis ifrs-full:RangeAxis
3430 Ranges [member] Member ifrs-full:RangesMember
3431 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
3432 Top of range [member] Member ifrs-full:TopOfRangeMember
3433 Types of risks [axis] Axis ifrs-full:TypesOfRisksAxis
3434 Risks [member] Member ifrs-full:TypesOfRisksMember
3435 Credit Risk [Member] Member ifrs-full:CreditRiskMember
3436 Types of interest rates [axis] Axis ifrs-full:TypesOfInterestRatesAxis
3437 Interest rate types [member] Member ifrs-full:InterestRateTypesMember
3438 A1 [Member] Member xcmig:A1RatingMember
3439 A2 Rating [Member] Member xcmig:A2RatingMember
3440 B [Member] Member xcmig:BRatingMember
3441 Disclosure of credit risk exposure [line items] LineItems ifrs-full:DisclosureOfCreditRiskExposureLineItems
3442 Bank equity Concept (Monetary) As Of Credit xcmig:BankEquityValue
3443 Concentration Concept (Text/String) For Period ifrs-full:DescriptionOfSharedCharacteristicForConcentration
3444 Percentage of limit per bank entity Concept (Percent) For Period xcmig:PercentageOfLimitPerBankEntity
3445 1211 - Disclosure - Financial Instruments and Risk Management - Summary of Net Liabilities in Relation to its Equity (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureFinancialInstrumentsAndRiskManagementSummaryOfNetLiabilitiesInRelationToItsEquity
3446 Disclosure of financial liabilities [table] Table

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*

 ifrs-full:DisclosureOfFinancialLiabilitiesTable
3447 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
3448 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
3449 Capital management [member] Member xcmig:CapitalManagementMember
3450 Disclosure of financial liabilities [line items] LineItems ifrs-full:DisclosureOfFinancialLiabilitiesLineItems
3451 Total liabilities Concept (Monetary) As Of Credit ifrs-full:Liabilities
3452 (-) Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
3453 (-) Restricted cash Concept (Monetary) As Of Debit xcmig:RestrictedCash1
3454 Net assets (liabilities) exposed Concept (Monetary) As Of Debit ifrs-full:NetAssetsLiabilities
3455 Total equity Concept (Monetary) As Of Credit ifrs-full:Equity
3456 Net liabilities / equity Concept (Percent) For Period xcmig:NetLiabilitiesToEquityRatio
3457 1212 - Disclosure - Measurement at Fair Value - Summary of Instruments Measured at Fair Value (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureMeasurementAtFairValueSummaryOfInstrumentsMeasuredAtFairValue
3458 Disclosure of financial assets and liabilities measured at fair value [Table] Table

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*

 xcmig:DisclosureOfFinancialAssetsAndLiabilitiesMeasuredAtFairValueTable
3459 Levels of fair value hierarchy [axis] Axis ifrs-full:LevelsOfFairValueHierarchyAxis
3460 All levels of fair value hierarchy [member] Member ifrs-full:AllLevelsOfFairValueHierarchyMember
3461 Level 1 [member] Member ifrs-full:Level1OfFairValueHierarchyMember
3462 Level 2 [member] Member ifrs-full:Level2OfFairValueHierarchyMember
3463 Level 3 [member] Member ifrs-full:Level3OfFairValueHierarchyMember
3464 Categories of financial assets [axis] Axis ifrs-full:CategoriesOfFinancialAssetsAxis
3465 Financial assets, category [member] Member ifrs-full:FinancialAssetsCategoryMember
3466 Financial assets at fair value through profit or loss, classified as held for trading, category [member] Member ifrs-full:FinancialAssetsAtFairValueThroughProfitOrLossClassifiedAsHeldForTradingCategoryMember
3467 Financial assets available-for-sale, category [member] Member ifrs-full:FinancialAssetsAvailableforsaleCategoryMember
3468 Financial assets at fair value through profit or loss, category [member] Member ifrs-full:FinancialAssetsAtFairValueThroughProfitOrLossCategoryMember
3469 Categories of financial liabilities [axis] Axis ifrs-full:CategoriesOfFinancialLiabilitiesAxis
3470 Financial liabilities, category [member] Member ifrs-full:FinancialLiabilitiesCategoryMember
3471 Financial liabilities at fair value through profit or loss, category [member] Member ifrs-full:FinancialLiabilitiesAtFairValueThroughProfitOrLossCategoryMember
3472 Classes of financial liabilities [axis] Axis ifrs-full:ClassesOfFinancialLiabilitiesAxis
3473 Financial liabilities, class [member] Member ifrs-full:FinancialLiabilitiesMember
3474 Derivative financial instruments [member] Member xcmig:DerivativeFinancialInstrumentsMember
3475 Derivative Financial Instruments Sale Option [member] Member xcmig:DerivativeFinancialInstrumentsSaleOptionMember
3476 Classes of financial assets [axis] Axis ifrs-full:ClassesOfFinancialAssetsAxis
3477 Financial assets, class [member] Member ifrs-full:FinancialAssetsMember
3478 Bank certificates of deposit [member] Member xcmig:BankCertificateOfDepositsMember
3479 Treasury financial notes (LFTs) [member] Member xcmig:TreasuryFinancialNotesMember
3480 Bank financial notes [Member] Member xcmig:BankFinancialNotesMember
3481 Debentures [member] Member xcmig:DebenturesMember
3482 Infrastructure -Distribution [Member] Member xcmig:InfrastructureDistributionMember
3483 Derivatives [member] Member ifrs-full:DerivativesMember
3484 Disclosure of financial assets and liabilities measured at fair value [Line Items] LineItems xcmig:DisclosureOfFinancialAssetsAndLiabilitiesMeasuredAtFairValueLineItems
3485 Financial assets Concept (Monetary) As Of Debit ifrs-full:FinancialAssetsAtFairValue
3486 Financial liabilities Concept (Monetary) As Of Credit ifrs-full:FinancialLiabilitiesAtFairValue
3487 Fair value through profit or loss Concept (Monetary) As Of Debit xcmig:NetFinancialAssetsAndFinancialLiabilitiesAtFairValue
3488 1213 - Disclosure - Insurance - Summary of Amounts Arising From Insurance Contracts (Detail) Network

*

*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureInsuranceSummaryOfAmountsArisingFromInsuranceContracts
3489 Disclosure of types of insurance contracts [table] Table

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*

 ifrs-full:DisclosureOfTypesOfInsuranceContractsTable
3490 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
3491 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
3492 Companhia Energetica de Minas Gerais Holding [Member] Member xcmig:CompanhiaEnergeticadeMinasGeraisHoldingMember
3493 Cemig Geracao e Transmissao [member] Member xcmig:CemigGeracaoETransmissaoMember
3494 Cemig Distribution [member] Member xcmig:CemigDistributionMember
3495 Gasmig [member] Member xcmig:GasmigMember
3496 Range [axis] Axis ifrs-full:RangeAxis
3497 Ranges [member] Member ifrs-full:RangesMember
3498 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
3499 Top of range [member] Member ifrs-full:TopOfRangeMember
3500 Types of insurance contracts [axis] Axis ifrs-full:TypesOfInsuranceContractsAxis
3501 Types of insurance contracts [member] Member ifrs-full:InsuranceContractsMember
3502 Facilities in buildings [member] Member xcmig:FacilitiesInBuildingsMember
3503 Air transport Aircraft Fuselage [member] Member xcmig:AirTransportAircraftFuselageMember
3504 Air transport [member] Member xcmig:AirTransportAircraftThirdPartyLiabilityMember
3505 Ware house stores [member] Member xcmig:WareHouseStoresMember
3506 Buildings [member] Member ifrs-full:BuildingsMember
3507 Telecoms equipment [member] Member xcmig:TelecomsEquipmentMember
3508 Operational risk [member] Member xcmig:OperationalRiskMember
3509 Gas Distribution Network Third Party [Member] Member xcmig:GasDistributionNetworkThirdPartyMember
3510 Own Vehicle Fleet Operation [Member] Member xcmig:OwnVehicleFleetOperationMember
3511 Own Vehicle Fleet Directors [Member] Member xcmig:OwnVehicleFleetDirectorsMember
3512 Facilities Multirisk [Member] Member xcmig:FacilitiesMultiriskMember
3513 Disclosure of types of insurance contracts [line items] LineItems ifrs-full:DisclosureOfTypesOfInsuranceContractsLineItems
3514 Cover Concept (Text/String) For Period xcmig:TypeOfInsuranceCoverage
3515 Dates of cover Concept (Text/String) For Period xcmig:InsuranceCoveragePeriodOne
3516 Amount insured Concept (Monetary) As Of Debit ifrs-full:AssetsUnderInsuranceContractsAndReinsuranceContractsIssued
3517 Annual premium Concept (Monetary) For Period Credit ifrs-full:PremiumsWrittenNetOfReinsurance
3518 1214 - Disclosure - Insurance - Summary of Amounts Arising From Insurance Contracts (Parenthetical) (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureInsuranceSummaryOfAmountsArisingFromInsuranceContractsParenthetical
3519 Disclosure of types of insurance contracts [table] Table

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*

 ifrs-full:DisclosureOfTypesOfInsuranceContractsTable
3520 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
3521 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
3522 Cemig Geracao e Transmissao [member] Member xcmig:CemigGeracaoETransmissaoMember
3523 Cemig Distribution [member] Member xcmig:CemigDistributionMember
3524 Disclosure of types of insurance contracts [line items] LineItems ifrs-full:DisclosureOfTypesOfInsuranceContractsLineItems
3525 Expense arising from insurance Concept (Monetary) For Period Debit ifrs-full:ExpenseArisingFromInsuranceContracts
3526 Maximum indemnity limit Concept (Monetary) As Of Debit xcmig:MaximumIndemnityLimitOfInsuranceContract
3527 1215 - Disclosure - Commitments - Detailed Information about Contractual Obligations and Commitments (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureCommitmentsDetailedInformationAboutContractualObligationsAndCommitments
3528 Disclosure Of Commitments [Table] Table

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*

 xcmig:DisclosureOfCommitmentsTable
3529 Maturity [axis] Axis ifrs-full:MaturityAxis
3530 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
3531 2018 [member] Member ifrs-full:NotLaterThanOneYearMember
3532 2019 [member] Member xcmig:NotLaterThanTwoYearMember
3533 2020 [member] Member xcmig:NotLaterThanThreeYearMember
3534 2021 [member] Member xcmig:NotLaterThanFourYearMember
3535 2022 [member] Member xcmig:NotLaterThanFiveYearMember
3536 After 2022 [member] Member xcmig:NotLaterThanSixYearMember
3537 Classes of financial instruments [axis] Axis ifrs-full:ClassesOfFinancialInstrumentsAxis
3538 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
3539 Purchase of energy from Itaip [member] Member xcmig:PurchaseOfEnergyItaipuMember
3540 Purchase of energy auctions [member] Member xcmig:PurchaseOfEnergyAuctionsMember
3541 Purchase of energy bilateral contracts [member] Member xcmig:PurchaseOfEnergyBilateralContractsMember
3542 Quotas for Angra [member] Member xcmig:QuotasForAngraMember
3543 Transport of energy from Itaipu [member] Member xcmig:EnergyTransportMember
3544 Other energy purchase contracts [member] Member xcmig:OtherEnergyPurchaseContractsMember
3545 Gas Distribution [member] Member ifrs-full:GasDistributionMember
3546 Operating Lease [member] Member xcmig:OperatingLeaseMember
3547 Disclosure of commitments [Line Items] LineItems xcmig:DisclosureOfCommitmentsLineItems
3548 Contractual obligations and commitments Concept (Monetary) As Of Credit ifrs-full:ContractualCapitalCommitments
3549 1216 - Disclosure - The Annual Tariff Adjustment- Additional Information (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureTheAnnualTariffAdjustmentAdditionalInformation
3550 Disclosure Of Financial Assets And Financial Liabilities With The Tariff Adjustments [table] Table

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*

 xcmig:DisclosureOfFinancialAssetsAndFinancialLiabilitiesWithTheTariffAdjustmentsTable
3551 Classes of financial instruments [axis] Axis ifrs-full:ClassesOfFinancialInstrumentsAxis
3552 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
3553 Cost items adjustment [member] Member xcmig:CostItemsAdjustmentMember
3554 Inclusion of financial components adjustment [member] Member xcmig:InclusionOfFinancialComponentsAdjustmentMember
3555 Removal of financial components adjustment [member] Member xcmig:RemovalOfFinancialComponentsAdjustmentMember
3556 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
3557 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
3558 Cemig Distribution [member] Member xcmig:CemigDistributionMember
3559 Disclosure Of Financial Assets And Financial Liabilities With The Tariff Adjustments [Line Items] LineItems xcmig:DisclosureOfFinancialAssetsAndFinancialLiabilitiesWithTheTariffAdjustmentsLineItems
3560 Percentage of decrease in annual tariffs Concept (Percent) For Period xcmig:PercentageOfDecreaseInAnnualTariff
3561 Percentage of annual tariffs adjustment Concept (Percent) For Period xcmig:PercentageOfAnnualTariffAdjustment
3562 1217 - Disclosure - Non-Cash Transactions - Additional Information (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureNonCashTransactionsAdditionalInformation
3563 Implied Table Table

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*

 implied:Table
3564 Non Cash Transactions [abstract] Abstract xcmig:NonCashTransactionsAbstract
3565 Capitalized financial costs Concept (Monetary) For Period Credit xcmig:FinancialChargesCapitalized
3566 1218 - Disclosure - Subsequent Events - Additional Information (Detail) Network

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*

 http://imetrix.edgar-online.com/taxonomy/role/DisclosureSubsequentEventsAdditionalInformation
3567 Disclosure of non-adjusting events after reporting period [table] Table

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*

 ifrs-full:DisclosureOfNonadjustingEventsAfterReportingPeriodTable
3568 Non-adjusting events after reporting period [axis] Axis ifrs-full:NonadjustingEventsAfterReportingPeriodAxis
3569 Non-adjusting events after reporting period [member] Member ifrs-full:NonadjustingEventsMember
3570 Entering into significant commitments or contingent liabilities [member] Member ifrs-full:EnteringIntoSignificantCommitmentsOrContingentLiabilitiesMember
3571 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
3572 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
3573 Promissory Notes [member] Member xcmig:PromissoryNotesMember
3574 Range [axis] Axis ifrs-full:RangeAxis
3575 Ranges [member] Member ifrs-full:RangesMember
3576 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
3577 Top of range [member] Member ifrs-full:TopOfRangeMember
3578 Types of share-based payment arrangements [axis] Axis ifrs-full:TypesOfSharebasedPaymentArrangementsAxis
3579 Share-based payment arrangements [member] Member ifrs-full:SharebasedPaymentArrangementsMember
3580 Two Thousand Eighteen Employee Voluntary Severance Program [Member] Member xcmig:TwoThousandEighteenEmployeeVoluntarySeveranceProgramMember
3581 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
3582 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
3583 Ceming GT [Member] Member xcmig:CemingGTMember
3584 Chipley [member] Member xcmig:ChipleyMember
3585 Renova [member] Member xcmig:RenovaMember
3586 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
3587 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
3588 Ordinary shares [member] Member ifrs-full:OrdinarySharesMember
3589 Preference shares [member] Member ifrs-full:PreferenceSharesMember
3590 Common shares [member] Member xcmig:CommonSharesMember
3591 Types of interest rates [axis] Axis ifrs-full:TypesOfInterestRatesAxis
3592 Interest rate types [member] Member ifrs-full:InterestRateTypesMember
3593 Interbank deposit certificate CDI rate [member] Member xcmig:InterbankDepositCertificateCdiRateMember
3594 Disclosure of non-adjusting events after reporting period [line items] LineItems ifrs-full:DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems
3595 Description of type of retirement benefit plan Concept (Text/String) For Period ifrs-full:DescriptionOfTypeOfRetirementBenefitPlan
3596 Description of eligible employees to take part of plan Concept (Text/String) For Period ifrs-full:ExplanationOfWhetherParticipantsContributeToRetirementBenefitPlan
3597 Description of benefits to participants Concept (Text/String) For Period ifrs-full:DescriptionOfRetirementBenefitsPromisedToParticipants
3598 Percentage of penalty payment on base value of the employee's FGTS fund Concept (Percent) For Period xcmig:PercentageOfPenaltyPaymentOnBaseValueOfEmployeeFgtsFund
3599 Advanced payment for power supply Concept (Monetary) For Period Credit xcmig:AdvancedPaymentForPowerSupply
3600 Advanced discount percentage Concept (Percent) For Period xcmig:PercentageOfEarlyPaymentDiscount
3601 Financial volume from stock issuance Concept (Monetary) For Period Credit xcmig:SharesIssuedValue
3602 Number of shares issued Concept (Shares) As Of ifrs-full:NumberOfSharesIssued
3603 Average price per share Concept (Share) As Of xcmig:AveragePricePerShare
3604 Share price Concept (Monetary) For Period xcmig:SharePrice1
3605 Capital increase Concept (Monetary) For Period Credit xcmig:IncreaseInAuthorizedCapital
3606 New shares authorized Concept (Shares) For Period xcmig:IncreaseInNumberOfAuthorizedShares
3607 Par value per share Concept (Share) As Of xcmig:ParValuePerShareOfAuthorisedShares
3608 Proceeds from issuance capital Concept (Monetary) For Period Debit xcmig:ProceedsFromIssuanceOfCapitalStock
3609 Capital reserve Concept (Monetary) As Of Credit ifrs-full:CapitalReserve
3610 Borrowings Concept (Monetary) For Period ifrs-full:BorrowingCostsIncurred
3611 Debt instrument interest rate Concept (Percent) For Period xcmig:DebtInstrumentInterestRate
3612 Percentage of shares to be acquired Concept (Percent) As Of ifrs-full:PercentageOfVotingEquityInterestsAcquired

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