UNITED MICROELECTRONICS CORP (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://www.umc.com/taxonomy/role/DocumentandEntityInformation
2 Implied Table Table

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 implied:Table
3 Document - Document and Entity Information [Abstract] Abstract umc: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 Balance Sheets Network

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 http://www.umc.com/taxonomy/role/StatementOfFinancialPositionCurrentNonCurrent-210000
18 Implied Table Table

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 implied:Table
19 Statement of financial position [abstract] Abstract ifrs-full:StatementOfFinancialPositionAbstract
20 Assets Abstract ifrs-full:AssetsAbstract
21 Current assets Abstract ifrs-full:CurrentAssetsAbstract
22 Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
23 Financial assets at fair value through profit or loss, current Concept (Monetary) As Of Debit ifrs-full:CurrentFinancialAssetsAtFairValueThroughProfitOrLoss
24 Contract assets, current Concept (Monetary) As Of Debit ifrs-full:CurrentContractAssets
25 Notes receivable Concept (Monetary) As Of Debit umc:CurrentNotesReceivable
26 Accounts receivable, net Concept (Monetary) As Of Debit ifrs-full:CurrentTradeReceivables
27 Accounts receivable-related parties, net Concept (Monetary) As Of Debit ifrs-full:TradeAndOtherCurrentReceivablesDueFromRelatedParties
28 Other receivables Concept (Monetary) As Of Debit ifrs-full:OtherCurrentReceivables
29 Current tax assets Concept (Monetary) As Of Debit ifrs-full:CurrentTaxAssetsCurrent
30 Inventories, net Concept (Monetary) As Of Debit ifrs-full:Inventories
31 Other current assets Concept (Monetary) As Of Debit ifrs-full:OtherCurrentAssets
32 Total current assets Concept (Monetary) As Of Debit ifrs-full:CurrentAssets
33 Non-current assets Abstract ifrs-full:NoncurrentAssetsAbstract
34 Financial assets at fair value through profit or loss, noncurrent Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssetsAtFairValueThroughProfitOrLoss
35 Financial assets at fair value through other comprehensive income, noncurrent Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssetsAtFairValueThroughOtherComprehensiveIncome
36 Available-for-sale financial assets, noncurrent Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssetsAvailableforsale
37 Financial assets measured at cost, noncurrent Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssetsAtAmortisedCost
38 Investments accounted for under the equity method Concept (Monetary) As Of Debit ifrs-full:InvestmentAccountedForUsingEquityMethod
39 Property, plant and equipment Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
40 Intangible assets Concept (Monetary) As Of Debit ifrs-full:IntangibleAssetsAndGoodwill
41 Deferred tax assets Concept (Monetary) As Of Debit ifrs-full:DeferredTaxAssets
42 Prepayment for equipment Concept (Monetary) As Of Debit ifrs-full:NoncurrentPrepayments
43 Refundable deposits Concept (Monetary) As Of Debit ifrs-full:LongtermDeposits
44 Other noncurrent assets Concept (Monetary) As Of Debit ifrs-full:OtherNoncurrentAssets
45 Total non-current assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentAssets
46 Total assets Concept (Monetary) As Of Debit ifrs-full:Assets
47 Liabilities and Equity Abstract ifrs-full:EquityAndLiabilitiesAbstract
48 Current liabilities Abstract ifrs-full:CurrentLiabilitiesAbstract
49 Short-term loans Concept (Monetary) As Of Credit ifrs-full:ShorttermBorrowings
50 Contract liabilities, current Concept (Monetary) As Of Credit ifrs-full:CurrentContractLiabilities
51 Notes and accounts payable Concept (Monetary) As Of Credit umc:CurrentNotesAndAccountsPayable
52 Other payables Concept (Monetary) As Of Credit ifrs-full:OtherCurrentPayables
53 Payables on equipment Concept (Monetary) As Of Credit ifrs-full:CurrentPayablesForPurchaseOfNoncurrentAssets
54 Current tax liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentTaxLiabilitiesCurrent
55 Current portion of long-term liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentPortionOfLongtermBorrowings
56 Other current liabilities Concept (Monetary) As Of Credit ifrs-full:OtherCurrentLiabilities
57 Total current liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentLiabilities
58 Non-current liabilities Abstract ifrs-full:NoncurrentLiabilitiesAbstract
59 Bonds payable Concept (Monetary) As Of Credit ifrs-full:NoncurrentPortionOfNoncurrentBondsIssued
60 Long-term loans Concept (Monetary) As Of Credit ifrs-full:NoncurrentPortionOfNoncurrentLoansReceived
61 Deferred tax liabilities Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilities
62 Net defined benefit liabilities, noncurrent Concept (Monetary) As Of Credit ifrs-full:NoncurrentRecognisedLiabilitiesDefinedBenefitPlan
63 Guarantee deposits Concept (Monetary) As Of Credit umc:NoncurrentGuaranteeDeposits
64 Other noncurrent liabilities Concept (Monetary) As Of Credit ifrs-full:OtherNoncurrentLiabilities
65 Total non-current liabilities Concept (Monetary) As Of Credit ifrs-full:NoncurrentLiabilities
66 Total liabilities Concept (Monetary) As Of Credit ifrs-full:Liabilities
67 Commitments and contingencies Concept (Monetary) As Of Credit umc:CommitmentsAndContingencies1
68 Equity attributable to the parent company Capital Abstract ifrs-full:EquityAbstract
69 Capital Abstract umc:Capital1Abstract
70 Common stock - NT$10 par value Authorized: 26,000,000 thousand shares Issued: 12,624,319 thousand shares as of December 31, 2017 Issued: 12,424,319 thousand shares as of December 31, 2018 Concept (Monetary) As Of Credit ifrs-full:IssuedCapital
71 Additional paid-in capital Abstract umc:AdditionalPaidInCapital1Abstract
72 Premiums Concept (Monetary) As Of Credit ifrs-full:SharePremium
73 Treasury stock transactions Concept (Monetary) As Of Credit ifrs-full:CapitalRedemptionReserve
74 Transactions with noncontrolling interests Concept (Monetary) As Of Credit umc:TransactionsWithNoncontrollingInterests
75 Share-based payment Concept (Monetary) As Of Credit umc:ReserveFromSharebasedPaymentTransactions
76 Stock options - conversion right Concept (Monetary) As Of Credit ifrs-full:ReserveOfEquityComponentOfConvertibleInstruments
77 Other Concept (Monetary) As Of Credit ifrs-full:OtherEquityInterest
78 Retained earnings Abstract umc:RetainedEarningsAbstract
79 Legal reserve Concept (Monetary) As Of Credit ifrs-full:StatutoryReserve
80 Unappropriated earnings Concept (Monetary) As Of Credit umc:UnappropriatedEarnings
81 Other components of equity Abstract ifrs-full:OtherReservesAbstract
82 Exchange differences on translation of foreign operations Concept (Monetary) As Of Credit ifrs-full:ReserveOfExchangeDifferencesOnTranslation
83 Unrealized gains or losses on financial assets measured at fair value through other comprehensive income Concept (Monetary) As Of Credit ifrs-full:ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome
84 Unrealized gains or losses on available-for-sale financial assets Concept (Monetary) As Of Credit ifrs-full:ReserveOfGainsAndLossesOnRemeasuringAvailableforsaleFinancialAssets
85 Gains or losses on hedging instruments Concept (Monetary) As Of Credit ifrs-full:ReserveOfCashFlowHedges
86 Treasury stock Concept (Monetary) As Of Debit ifrs-full:TreasuryShares
87 Total equity attributable to the parent company Concept (Monetary) As Of Credit ifrs-full:EquityAttributableToOwnersOfParent
88 Non-controlling interests Concept (Monetary) As Of Credit ifrs-full:NoncontrollingInterests
89 Total equity Concept (Monetary) As Of Credit ifrs-full:Equity
90 Total liabilities and equity Concept (Monetary) As Of Credit ifrs-full:EquityAndLiabilities
91 1004 - Statement - Consolidated Balance Sheets (Parenthetical) Network

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 http://www.umc.com/taxonomy/role/StatementOfFinancialPositionCurrentNonCurrent-210000Parenthetical
92 Implied Table Table

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 implied:Table
93 Statement of financial position [abstract] Abstract ifrs-full:StatementOfFinancialPositionAbstract
94 Common stock, par value Concept (Share) As Of ifrs-full:ParValuePerShare
95 Common stock, shares authorized Concept (Shares) As Of ifrs-full:NumberOfSharesAuthorised
96 Common stock, shares issued Concept (Shares) As Of ifrs-full:NumberOfSharesIssued
97 1005 - Statement - Consolidated Statements of Comprehensive Income Network

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 http://www.umc.com/taxonomy/role/StatementOfComprehensiveIncomeProfitOrLossByNatureOfExpense-320000
98 Implied Table Table

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 implied:Table
99 Statement of comprehensive income [abstract] Abstract ifrs-full:StatementOfComprehensiveIncomeAbstract
100 Operating revenues Concept (Monetary) For Period Credit ifrs-full:Revenue
101 Operating costs Concept (Monetary) For Period Debit ifrs-full:CostOfSales
102 Gross profit Concept (Monetary) For Period Credit ifrs-full:GrossProfit
103 Operating expenses Abstract umc:OperatingExpenses1Abstract
104 Sales and marketing expenses Concept (Monetary) For Period Debit ifrs-full:SalesAndMarketingExpense
105 General and administrative expenses Concept (Monetary) For Period Debit ifrs-full:GeneralAndAdministrativeExpense
106 Research and development expenses Concept (Monetary) For Period Debit ifrs-full:ResearchAndDevelopmentExpense
107 Expected credit losses Concept (Monetary) For Period Debit umc:ExpectedCreditLoss
108 Subtotal Concept (Monetary) For Period Debit ifrs-full:OperatingExpenseExcludingCostOfSales
109 Net other operating income and expenses Concept (Monetary) For Period Credit ifrs-full:OtherOperatingIncomeExpense
110 Operating income Concept (Monetary) For Period Credit ifrs-full:ProfitLossFromOperatingActivities
111 Non-operating income and expenses Abstract umc:NonOperatingIncomeAndExpensesAbstract
112 Other income Concept (Monetary) For Period Credit ifrs-full:OtherIncome
113 Other gains and losses Concept (Monetary) For Period Credit ifrs-full:OtherGainsLosses
114 Finance costs Concept (Monetary) For Period Debit ifrs-full:FinanceCosts
115 Share of profit or loss of associates and joint ventures Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
116 Bargain purchase gain in acquisition of additional shares of equity investees Concept (Monetary) For Period Credit umc:BargainPurchaseGain
117 Exchange gain, net Concept (Monetary) For Period Credit ifrs-full:NetForeignExchangeGain
118 Exchange loss, net Concept (Monetary) For Period Debit ifrs-full:NetForeignExchangeLoss
119 Subtotal Concept (Monetary) For Period Credit umc:NonoperatingIncomeAndExpenses
120 Income from continuing operations before income tax Concept (Monetary) For Period Credit ifrs-full:ProfitLossBeforeTax
121 Income tax benefit (expense) Concept (Monetary) For Period Debit ifrs-full:IncomeTaxExpenseContinuingOperations
122 Net income Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
123 Other comprehensive income (loss) Abstract ifrs-full:OtherComprehensiveIncomeAbstract
124 Items that will not be reclassified subsequently to profit or loss Abstract ifrs-full:ComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTaxAbstract
125 Remeasurements of defined benefit pension plans Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans
126 Unrealized gains or losses on financial assets at fair value through other comprehensive income Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeBeforeTax
127 Gains or losses on hedging instruments which will not be reclassified subsequently to profit or loss Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnCashFlowHedgesBeforeTax
128 Share of other comprehensive income (loss) of associates and joint ventures which will not be reclassified subsequently to profit or loss Concept (Monetary) For Period Credit ifrs-full:ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillNotBeReclassifiedToProfitOrLossBeforeTax
129 Income tax related to items that will not be reclassified subsequently Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLoss
130 Subtotal Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossNetOfTax
131 Items that may be reclassified subsequently to profit or loss Abstract ifrs-full:ComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTaxAbstract
132 Exchange differences on translation of foreign operations Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeBeforeTaxExchangeDifferencesOnTranslation
133 Unrealized gains or losses on available-for-sale financial assets Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeBeforeTaxAvailableforsaleFinancialAssets
134 Share of other comprehensive income (loss) of associates and joint ventures which may be reclassified subsequently to profit or loss Concept (Monetary) For Period Credit ifrs-full:ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillBeReclassifiedToProfitOrLossBeforeTax
135 Income tax related to items that may be reclassified subsequently Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLoss
136 Subtotal Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTax
137 Total other comprehensive income (loss), net of tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncome
138 Total comprehensive income Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncome
139 Net income attributable to: Abstract ifrs-full:ProfitLossAttributableToAbstract
140 Stockholders of the parent Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToOwnersOfParent
141 Non-controlling interests Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToNoncontrollingInterests
142 Net income Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
143 Total comprehensive income attributable to: Abstract ifrs-full:ComprehensiveIncomeAttributableToAbstract
144 Stockholders of the parent Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncomeAttributableToOwnersOfParent
145 Non-controlling interests Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncomeAttributableToNoncontrollingInterests
146 Total comprehensive income Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncome
147 Earnings per share (NTD) Abstract ifrs-full:EarningsPerShareAbstract
148 Earnings per share-basic Concept (Share) For Period ifrs-full:BasicEarningsLossPerShare
149 Earnings per share-diluted Concept (Share) For Period ifrs-full:DilutedEarningsLossPerShare
150 1006 - Statement - Consolidated Statements of Changes in Equity Network

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 http://www.umc.com/taxonomy/role/StatementOfChangesInEquity-610000
151 Statement of changes in equity [table] Table

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 ifrs-full:StatementOfChangesInEquityTable
152 Components of equity [axis] Axis ifrs-full:ComponentsOfEquityAxis
153 Equity [member] Member ifrs-full:EquityMember
154 Capital [member] Member ifrs-full:IssuedCapitalMember
155 Additional paid-in capital [member] Member ifrs-full:AdditionalPaidinCapitalMember
156 Legal reserve [member] Member ifrs-full:StatutoryReserveMember
157 Unappropriated earnings [member] Member umc:UnappropriatedEarningsMember
158 Exchange differences on translation of foreign operations [member] Member ifrs-full:ReserveOfExchangeDifferencesOnTranslationMember
159 Unrealized gain or loss on available-for-sale financial assets [member] Member ifrs-full:ReserveOfGainsAndLossesOnRemeasuringAvailableforsaleFinancialAssetsMember
160 Treasury stock [member] Member ifrs-full:TreasurySharesMember
161 Equity attributable to the parent company [member] Member ifrs-full:EquityAttributableToOwnersOfParentMember
162 Non-controlling interests [member] Member ifrs-full:NoncontrollingInterestsMember
163 Reserve of gains and losses on financial assets measured at fair value through other comprehensive income [member] Member ifrs-full:ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember
164 Reserve of cash flow hedges [member] Member ifrs-full:ReserveOfCashFlowHedgesMember
165 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
166 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
167 Common stocks [member] Member ifrs-full:OrdinarySharesMember
168 Statement of changes in equity [line items] LineItems ifrs-full:StatementOfChangesInEquityLineItems
169 Balance Concept (Monetary) As Of Credit ifrs-full:Equity
170 Impact of retroactive applications Concept (Monetary) For Period Debit umc:CumulativeEffectsOfNewAccountingPrincipleInPeriodOfAdoption
171 Adjusted balance as of January 1, 2018 Concept (Monetary) As Of Credit umc:StockholdersEquityAdjustedBalance
172 Appropriation and distribution of retained earnings Abstract umc:AppropriationAndDistributionOfRetainedEarningsAbstract
173 Legal reserve Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughTransferToStatutoryReserve
174 Cash dividends Concept (Monetary) For Period Debit ifrs-full:DividendsRecognisedAsDistributionsToOwnersOfParent
175 Net income Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
176 Other comprehensive income (loss), net of tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncome
177 Total comprehensive income (loss) Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncome
178 Share-based payment transaction Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughSharebasedPaymentTransactions
179 Treasury stock acquired Concept (Monetary) For Period Debit ifrs-full:PurchaseOfTreasuryShares
180 Treasury stock cancelled Concept (Monetary) For Period Credit ifrs-full:CancellationOfTreasuryShares
181 Share of changes in net assets of associates and joint ventures accounted for using equity method Concept (Monetary) For Period Credit umc:ShareOfChangesInNetAssetsOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
182 Disposal of subsidiaries Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughDisposalOfSubsidiary
183 Changes in subsidiaries' ownership Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughChangesInOwnershipInterestsInSubsidiariesThatDoNotResultInLossOfControl
184 Adjustments due to reciprocal stockholdings held by subsidiaries and associates Concept (Monetary) For Period Credit umc:IncreaseDecreaseThroughAdjustmentsDueToReciprocalStockholdingsHeldBySubsidiariesAndAssociates
185 Others Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughTransfersAndOtherChangesEquity
186 Balance Concept (Monetary) As Of Credit ifrs-full:Equity
187 1007 - Statement - Consolidated Statements of Cash Flows Network

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 http://www.umc.com/taxonomy/role/StatementOfCashFlowsIndirectMethod-520000
188 Implied Table Table

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 implied:Table
189 Statement of cash flows [abstract] Abstract ifrs-full:StatementOfCashFlowsAbstract
190 Cash flows from operating activities: Abstract ifrs-full:CashFlowsFromUsedInOperatingActivitiesAbstract
191 Net income before tax Concept (Monetary) For Period Credit ifrs-full:ProfitLossBeforeTax
192 Adjustments to reconcile net income before tax to net cash provided by operating activities: Abstract ifrs-full:AdjustmentsForReconcileProfitLossAbstract
193 Depreciation Concept (Monetary) For Period ifrs-full:DepreciationPropertyPlantAndEquipment
194 Amortization Concept (Monetary) For Period Debit ifrs-full:AmortisationExpense
195 Expected credit losses Concept (Monetary) For Period Debit umc:ExpectedCreditLoss
196 Bad debt expense (reversal) Concept (Monetary) For Period Debit ifrs-full:ImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLossTradeReceivables
197 Net (gain) loss of financial assets and liabilities at fair value through profit or loss Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForFairValueGainsLosses
198 Interest expense Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForInterestExpense
199 Interest income Concept (Monetary) For Period Credit ifrs-full:AdjustmentsForInterestIncome
200 Dividend income Concept (Monetary) For Period Credit ifrs-full:RevenueFromDividends
201 Share-based payment Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForSharebasedPayments
202 Share of loss (profit) of associates and joint ventures Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
203 Gain on disposal of property, plant and equipment Concept (Monetary) For Period Credit ifrs-full:GainsOnDisposalsOfPropertyPlantAndEquipment
204 Gain on disposal of other assets Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnDisposalsOfOtherNoncurrentAssets
205 (Gain) loss on disposal of investments Concept (Monetary) For Period Credit ifrs-full:GainsOnDisposalsOfInvestments
206 Impairment loss on financial assets Concept (Monetary) For Period Debit ifrs-full:ImpairmentLossOnFinancialAssets
207 Impairment loss on non-financial assets Concept (Monetary) For Period Debit ifrs-full:ImpairmentLossRecognisedInProfitOrLoss
208 Exchange loss (gain) on financial assets and liabilities Concept (Monetary) For Period Credit umc:AdjustmentsForExchangeLossGainOnFinancialAssetsAndLiabilities
209 Bargain purchase gain in acquisition of additional shares of equity investees Concept (Monetary) For Period Credit umc:BargainPurchaseGain
210 Amortization of deferred government grants Concept (Monetary) For Period Credit umc:AmortizationOfDeferredGovernmentGrants
211 Income and expense adjustments Concept (Monetary) For Period Debit ifrs-full:AdjustmentsToReconcileProfitLossOtherThanChangesInWorkingCapital
212 Changes in operating assets and liabilities: Abstract umc:ChangesInOperatingAssetsAndLiabilitiesAbstract
213 Financial assets and liabilities at fair value through profit or loss Concept (Monetary) For Period Debit umc:AdjustmentsForDecreaseIncreaseInFinancialAssetsAndLiabilitiesAtFairValueThroughProfitOrLoss
214 Contract assets Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughCumulativeCatchupAdjustmentsToRevenueContractAssets
215 Notes receivable and accounts receivable Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDecreaseIncreaseInTradeAccountReceivable
216 Other receivables Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDecreaseIncreaseInOtherOperatingReceivables
217 Inventories Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDecreaseIncreaseInInventories
218 Other current assets Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDecreaseIncreaseInOtherCurrentAssets
219 Contract fulfillment costs Concept (Monetary) For Period Debit umc:AdjustmentsForIncreaseDecreaseInContractFulfillmentCosts
220 Contract liabilities Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughCumulativeCatchupAdjustmentsToRevenueContractLiabilities
221 Notes and accounts payable Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForIncreaseDecreaseInTradeAccountPayable
222 Other payables Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForIncreaseDecreaseInOtherOperatingPayables
223 Other current liabilities Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForIncreaseDecreaseInOtherCurrentLiabilities
224 Net defined benefit liabilities Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForIncreaseDecreaseInEmployeeBenefitLiabilities
225 Other noncurrent liabilities Concept (Monetary) For Period Debit umc:AdjustmentsForIncreaseDecreaseInOtherNoncurrentLiabilities
226 Cash generated from operations Concept (Monetary) For Period ifrs-full:CashFlowsFromUsedInOperations
227 Interest received Concept (Monetary) For Period Debit ifrs-full:InterestReceivedClassifiedAsOperatingActivities
228 Dividend received Concept (Monetary) For Period Debit ifrs-full:DividendsReceivedClassifiedAsOperatingActivities
229 Interest paid Concept (Monetary) For Period Credit ifrs-full:InterestPaidClassifiedAsOperatingActivities
230 Income tax paid Concept (Monetary) For Period Credit ifrs-full:IncomeTaxesPaidRefundClassifiedAsOperatingActivities
231 Net cash provided by operating activities Concept (Monetary) For Period ifrs-full:CashFlowsFromUsedInOperatingActivities
232 Cash flows from investing activities: Abstract ifrs-full:CashFlowsFromUsedInInvestingActivitiesAbstract
233 Acquisition of financial assets at fair value through profit or loss Concept (Monetary) For Period Credit umc:PurchaseOfFinancialAssetsAtFairValueThroughProfitOrLoss
234 Proceeds from disposal of financial assets at fair value through profit or loss Concept (Monetary) For Period Debit umc:ProceedsFromDisposalOfFinancialAssetsAtFairValueThroughProfitOrLoss
235 Acquisition of available-for-sale financial assets Concept (Monetary) For Period Credit ifrs-full:PurchaseOfAvailableforsaleFinancialAssets
236 Proceeds from disposal of available-for-sale financial assets Concept (Monetary) For Period Debit ifrs-full:ProceedsFromDisposalOrMaturityOfAvailableforsaleFinancialAssets
237 Acquisition of financial assets measured at cost Concept (Monetary) For Period Credit umc:AcquisitionOfFinancialAssetsMeasuredAtCost
238 Proceeds from disposal of financial assets measured at cost Concept (Monetary) For Period Debit umc:ProceedsFromDisposalOfFinancialAssetsMeasuredAtCost
239 Acquisition of investments accounted for under the equity method Concept (Monetary) For Period Credit ifrs-full:PurchaseOfInterestsInInvestmentsAccountedForUsingEquityMethod
240 Increase in prepayment for investments Concept (Monetary) For Period Credit ifrs-full:PurchaseOfFinancialInstrumentsClassifiedAsInvestingActivities
241 Proceeds from capital reduction and liquidation of investments Concept (Monetary) For Period Debit umc:ProceedsFromCapitalReductionAndLiquidationOfInvestments
242 Disposal of subsidiaries Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromLosingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities
243 Derecognition of hedging financial assets and liabilities Concept (Monetary) For Period Credit umc:DerecognitionOfHedgingFinancialAssetsAndLiabilities
244 Acquisition of property, plant and equipment Concept (Monetary) For Period Credit ifrs-full:PurchaseOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities
245 Proceeds from disposal of property, plant and equipment Concept (Monetary) For Period Debit ifrs-full:ProceedsFromSalesOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities
246 Increase in refundable deposits Concept (Monetary) For Period Credit umc:IncreaseInRefundableDeposits
247 Decrease in refundable deposits Concept (Monetary) For Period Debit umc:DecreaseInRefundableDeposits
248 Acquisition of intangible assets Concept (Monetary) For Period Credit ifrs-full:PurchaseOfIntangibleAssetsClassifiedAsInvestingActivities
249 Government grants related to assets acquisition Concept (Monetary) For Period Debit ifrs-full:ProceedsFromGovernmentGrantsClassifiedAsInvestingActivities
250 Increase in other noncurrent assets Concept (Monetary) For Period Credit ifrs-full:PurchaseOfOtherLongtermAssetsClassifiedAsInvestingActivities
251 Decrease in other noncurrent assets Concept (Monetary) For Period Debit ifrs-full:ProceedsFromOtherLongtermAssetsClassifiedAsInvestingActivities
252 Net cash used in investing activities Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromUsedInInvestingActivities
253 Cash flows from financing activities: Abstract ifrs-full:CashFlowsFromUsedInFinancingActivitiesAbstract
254 Increase in short-term loans Concept (Monetary) For Period Debit ifrs-full:ProceedsFromCurrentBorrowings
255 Decrease in short-term loans Concept (Monetary) For Period Credit ifrs-full:RepaymentsOfCurrentBorrowings
256 Proceeds from bonds issued Concept (Monetary) For Period Debit ifrs-full:ProceedsFromIssueOfBondsNotesAndDebentures
257 Bonds issuance costs Concept (Monetary) For Period Credit ifrs-full:PaymentsForDebtIssueCosts
258 Redemption of bonds Concept (Monetary) For Period Credit ifrs-full:RepaymentsOfBondsNotesAndDebentures
259 Proceeds from long-term loans Concept (Monetary) For Period Debit ifrs-full:ProceedsFromNoncurrentBorrowings
260 Repayments of long-term loans Concept (Monetary) For Period Credit ifrs-full:RepaymentsOfNoncurrentBorrowings
261 Increase in guarantee deposits Concept (Monetary) For Period Debit umc:IncreaseInGuaranteeDeposits
262 Decrease in guarantee deposits Concept (Monetary) For Period Credit umc:DecreaseInGuaranteeDeposits
263 Increase in other financial liabilities Concept (Monetary) For Period Debit umc:IncreaseDecreaseInOtherFinancialLiabilities
264 Cash dividends Concept (Monetary) For Period Credit ifrs-full:DividendsPaidClassifiedAsFinancingActivities
265 Treasury stock acquired Concept (Monetary) For Period Credit ifrs-full:PaymentsToAcquireOrRedeemEntitysShares
266 Treasury stock sold to employees Concept (Monetary) For Period Debit ifrs-full:ProceedsFromSaleOrIssueOfTreasuryShares
267 Acquisition of non-controlling interests Concept (Monetary) For Period Credit ifrs-full:PaymentsFromChangesInOwnershipInterestsInSubsidiaries
268 Change in non-controlling interests Concept (Monetary) For Period Debit umc:ChangeInNoncontrollingInterestClassifiedAsFinancingActivities
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613 OMNI GLOBAL LIMITED (OMNI) [member] Member umc:OmniGlobalLimitedMember
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690 1041 - Disclosure - Contents of Significant Accounts - Financial Assets at Fair Value through Profit or Loss (Detail) Network

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758 Supplies and spare parts Concept (Monetary) As Of Debit umc:SuppliesAndSpareParts
759 Work in process Concept (Monetary) As Of Debit ifrs-full:WorkInProgress
760 Finished goods Concept (Monetary) As Of Debit ifrs-full:FinishedGoods
761 Total Concept (Monetary) As Of Debit ifrs-full:Inventories
762 1047 - Disclosure - Contents of Significant Accounts - Inventories, Net - Additional Information (Detail) Network

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763 Implied Table Table

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764 Classes of current inventories [abstract] Abstract ifrs-full:ClassesOfInventoriesAbstract
765 Inventories recognized in operating costs Concept (Monetary) For Period Debit ifrs-full:CostOfInventoriesRecognisedAsExpenseDuringPeriod
766 Write-down of inventories Concept (Monetary) For Period ifrs-full:InventoryWritedown2011
767 Loss from scrapped inventory Concept (Monetary) For Period Debit umc:LossRecognizedFromScrappedInventory
768 Production line recovery expenses Concept (Monetary) For Period Debit umc:ProductionLineRecoveryExpenses
769 Compensation received from insurance claims Concept (Monetary) For Period Credit ifrs-full:IncomeFromReimbursementsUnderInsurancePolicies
770 Inventories pledged Concept (Monetary) As Of Debit ifrs-full:InventoriesPledgedAsSecurityForLiabilities
771 1048 - Disclosure - Contents of Significant Accounts - Financial Assets at Fair Value through Other Comprehensive Income, Non-Current (Detail) Network

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772 Disclosure of financial assets [table] Table

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773 Classes of financial assets [axis] Axis ifrs-full:ClassesOfFinancialAssetsAxis
774 Financial assets, class [member] Member ifrs-full:FinancialAssetsMember
775 Common stocks [member] Member ifrs-full:OrdinarySharesMember
776 Preferred stocks [member] Member ifrs-full:PreferenceSharesMember
777 Disclosure of financial assets [line items] LineItems ifrs-full:DisclosureOfFinancialAssetsLineItems
778 Financial assets at fair value through other comprehensive income, non-current Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssetsAtFairValueThroughOtherComprehensiveIncome
779 1049 - Disclosure - Contents of Significant Accounts - Summary of Fair Value of Each Investment in Equity Instrument (Detail) Network

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780 Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [table] Table

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781 Classes of financial assets [axis] Axis ifrs-full:ClassesOfFinancialAssetsAxis
782 Financial assets, class [member] Member ifrs-full:FinancialAssetsMember
783 SILICON INTEGRATED SYSTEMS CORP. [member] Member umc:SiliconIntegratedSystemsCorpMember
784 UNIMICRON HOLDING LIMITED [member] Member umc:UnimicronHoldingLimitedMember
785 MIE FUJITSU SEMICONDUCTOR LIMITED [member] Member umc:MieFujitsuSemiconductorLimitedMember
786 UNIMICRON TECHNOLOGY CORP. [member] Member umc:UnimicronTechnologyCorpMember
787 ITE TECH. INC. [Member] Member umc:ITETechIncMember
788 NOVATEK MICROELECTRONICS CORP. [member] Member umc:NovatekMicroElectronicsCorpMember
789 SHIN-ETSU HANDOTAI TAIWAN CO., LTD. [member] Member umc:ShinEtsuHandotaiTaiwanCoLtdMember
790 MTIC HOLDINGS PTE. LTD. [member] Member umc:MTICHoldingsPteLtdMember
791 Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [line items] LineItems ifrs-full:DisclosureOfFairValueOfInvestmentsInEquityInstrumentsDesignatedAsMeasuredAtFairValueThroughOtherComprehensiveIncomeLineItems
792 Fair value of investments in equity instruments Concept (Monetary) As Of Debit ifrs-full:FairValueOfInvestmentsInEquityInstrumentsDesignatedAsMeasuredAtFairValueThroughOtherComprehensiveIncome
793 1050 - Disclosure - Contents of Significant Accounts - Available-For-Sale Financial Assets, Non-Current (Detail) Network

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794 Disclosure of financial assets [table] Table

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795 Classes of financial assets [axis] Axis ifrs-full:ClassesOfFinancialAssetsAxis
796 Financial assets, class [member] Member ifrs-full:FinancialAssetsMember
797 Common stocks [member] Member ifrs-full:OrdinarySharesMember
798 Preferred stocks [member] Member ifrs-full:PreferenceSharesMember
799 Funds [member] Member ifrs-full:InvestmentFundsMember
800 Disclosure of financial assets [line items] LineItems ifrs-full:DisclosureOfFinancialAssetsLineItems
801 Available-for-sale financial assets, non-current Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssetsAvailableforsale
802 1051 - Disclosure - Contents of Significant Accounts - Financial Assets Measured at Cost, Non-Current (Detail) Network

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803 Disclosure of financial assets [table] Table

*

*

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804 Classes of financial assets [axis] Axis ifrs-full:ClassesOfFinancialAssetsAxis
805 Financial assets, class [member] Member ifrs-full:FinancialAssetsMember
806 Common stocks [member] Member ifrs-full:OrdinarySharesMember
807 Preferred stocks [member] Member ifrs-full:PreferenceSharesMember
808 Funds [member] Member ifrs-full:InvestmentFundsMember
809 Disclosure of financial assets [line items] LineItems ifrs-full:DisclosureOfFinancialAssetsLineItems
810 Financial assets measured at cost, non-current Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssetsAtAmortisedCost
811 1052 - Disclosure - Contents of Significant Accounts - Details of Investments Accounted for Under the Equity Method (Detail) Network

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812 Investments In Associates And Joint Ventures [Table] Table

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813 Associates [axis] Axis ifrs-full:SignificantInvestmentsInAssociatesAxis
814 Entity's total for associates [member] Member ifrs-full:EntitysTotalForAssociatesMember
815 FARADAY TECHNOLOGY CORP. (FARADAY) [member] Member umc:FaradayTechnologyCorpMember
816 MTIC HOLDINGS PTE. LTD. [member] Member umc:MTICHoldingsPteLtdMember
817 YUNG LI INVESTMENTS, INC. [member] Member umc:YungLiInvestmentsIncMember
818 UNITECH CAPITAL INC. [member] Member umc:UnitechCapitalIncMember
819 TRIKNIGHT CAPITAL CORPORATION [member] Member umc:TriKnightCapitalCorporationMember
820 HSUN CHIEH INVESTMENT CO., LTD. [member] Member umc:HsunChiehInvestmentCoLtdMember
821 HSUN CHIEN CAPITAL CORP. [member] Member umc:HsunChienCapitalCorporationMember
822 CLIENTRON CORP. [member] Member umc:ClientronCorpMember
823 YANN YUAN INVESTMENT CO., LTD. [member] Member umc:YannYuanInvestmentCoLtdMember
824 VSENSE CO., LTD. [member] Member umc:VSenseCoLtdMember
825 UNITED LED CORPORATION HONG KONG LIMITED [member] Member umc:UnitedLEDCorporationHongKongLimitedMember
826 TRANSLINK CAPITAL PARTNERS I, L.P. [member] Member umc:TranslinkCapitalPartnersILPMember
827 CTC CAPITAL PARTNERS I, L.P. [member] Member umc:CTCCapitalPartnersILPMember
828 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
829 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
830 SHANDONG HUAHONG ENERGY INVEST CO., INC. (SHANDONG HUAHONG) [member] Member umc:ShandongHuahongEnergyInvestCoIncMember
831 WINAICO SOLAR PROJEKT 1 GMBH [member] Member umc:WINAICOSolarProjektGmbHMember
832 WINAICO IMMOBILIEN GMBH [member] Member umc:WINACICOImmobilienGmbHMember
833 Investments in associates and joint ventures [line items] LineItems umc:InvestmentsInAssociatesAndJointVenturesLineItems
834 Amount Concept (Monetary) As Of Debit ifrs-full:InvestmentAccountedForUsingEquityMethod
835 Percentage of ownership or voting rights, Associates Concept (Percent) For Period ifrs-full:ProportionOfOwnershipInterestInAssociate
836 Percentage of ownership or voting rights, Joint ventures Concept (Percent) For Period ifrs-full:ProportionOfOwnershipInterestInJointVenture
837 1053 - Disclosure - Contents of Significant Accounts - Investments Accounted For Under the Equity Method - Additional Information (Detail) Network

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838 Investments In Associates And Joint Ventures [Table] Table

*

*

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839 Classes of assets [axis] Axis ifrs-full:ClassesOfAssetsAxis
840 Assets [member] Member ifrs-full:ClassesOfAssetsMember
841 Investments with published price quotations [member] Member umc:InvestmentsWithPublishedPriceQuotationsMember
842 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
843 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
844 Aggregated individually immaterial associates and joint ventures [member] Member umc:AggregatedIndividuallyImmaterialAssociatesAndJointVenturesMember
845 Measurement [axis] Axis ifrs-full:MeasurementAxis
846 Aggregated measurement [member] Member ifrs-full:AggregatedMeasurementMember
847 Fair value [member] Member ifrs-full:AtFairValueMember
848 Investments in associates and joint ventures [line items] LineItems umc:InvestmentsInAssociatesAndJointVenturesLineItems
849 Investments accounted for using equity method for which there are published price quotations Concept (Monetary) As Of Debit ifrs-full:InvestmentAccountedForUsingEquityMethod
850 Exchange differences arising from translation of the foreign entity Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnExchangeDifferencesOnTranslationNetOfTax
851 1054 - Disclosure - Contents of Significant Accounts - Aggregate Amount of the Company's Share of its Individually Immaterial Associates (Detail) Network

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852 Disclosure of associates [table] Table

*

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853 Associates [axis] Axis ifrs-full:SignificantInvestmentsInAssociatesAxis
854 Entity's total for associates [member] Member ifrs-full:EntitysTotalForAssociatesMember
855 Aggregated individually immaterial associates [member] Member ifrs-full:AggregatedIndividuallyImmaterialAssociatesMember
856 Disclosure of associates [line items] LineItems ifrs-full:DisclosureOfSignificantInvestmentsInAssociatesLineItems
857 Profit (Loss) from continuing operations Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
858 Post-tax profit from discontinued operations Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfDiscontinuedOperationsOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
859 Other comprehensive income (loss) Concept (Monetary) For Period Credit ifrs-full:ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
860 Total comprehensive income (loss) Concept (Monetary) For Period Credit ifrs-full:ShareOfTotalComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
861 1055 - Disclosure - Contents of Significant Accounts - Aggregate Amount of the Company's Share of its Individually Immaterial Joint Ventures (Detail) Network

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862 Disclosure of joint ventures [table] Table

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*

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863 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
864 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
865 Aggregated individually immaterial joint ventures [member] Member ifrs-full:AggregatedIndividuallyImmaterialJointVenturesMember
866 Disclosure of joint ventures [line items] LineItems ifrs-full:DisclosureOfJointVenturesLineItems
867 Loss from continuing operations Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
868 Other comprehensive income (loss) Concept (Monetary) For Period Credit ifrs-full:ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
869 Total comprehensive income (loss) Concept (Monetary) For Period Credit ifrs-full:ShareOfTotalComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
870 1056 - Disclosure - Contents of Significant Accounts - Property, Plant and Equipment (Detail) Network

*

*

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871 Disclosure of detailed information about property, plant and equipment [table] Table

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872 Classes of property, plant and equipment [axis] Axis ifrs-full:ClassesOfPropertyPlantAndEquipmentAxis
873 Property, plant and equipment [member] Member ifrs-full:PropertyPlantAndEquipmentMember
874 Land [member] Member ifrs-full:LandMember
875 Buildings [member] Member ifrs-full:BuildingsMember
876 Machinery and equipment [member] Member umc:MachineryAndEquipment1Member
877 Transportation equipment [member] Member ifrs-full:VehiclesMember
878 Furniture and fixtures [member] Member ifrs-full:FixturesAndFittingsMember
879 Leasehold improvement [member] Member ifrs-full:LeaseholdImprovementsMember
880 Construction in progress and equipment awaiting inspection [member] Member ifrs-full:ConstructionInProgressMember
881 Carrying amount, accumulated depreciation, amortization and impairment and gross carrying amount [Axis] Axis ifrs-full:CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis
882 Carrying amount [member] Member ifrs-full:CarryingAmountMember
883 Cost [member] Member ifrs-full:GrossCarryingAmountMember
884 Accumulated depreciation, amortisation and impairment [member] Member ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember
885 Disclosure of detailed information about property, plant and equipment [line items] LineItems ifrs-full:DisclosureOfPropertyPlantAndEquipmentLineItems
886 Beginning balance Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
887 Additions Concept (Monetary) For Period Debit ifrs-full:AdditionsOtherThanThroughBusinessCombinationsPropertyPlantAndEquipment
888 Depreciation Concept (Monetary) For Period ifrs-full:DepreciationPropertyPlantAndEquipment
889 Disposals Concept (Monetary) For Period Credit ifrs-full:DisposalsPropertyPlantAndEquipment
890 Disposal of subsidiaries Concept (Monetary) For Period Credit ifrs-full:DecreaseThroughLossOfControlOfSubsidiaryPropertyPlantAndEquipment
891 Transfers and reclassifications Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughTransfersAndOtherChangesPropertyPlantAndEquipment
892 Exchange effect Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughNetExchangeDifferencesPropertyPlantAndEquipment
893 Ending balance Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
894 1057 - Disclosure - Contents of Significant Accounts - Property, Plant and Equipment - Additional Information (Detail) Network

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 http://www.umc.com/taxonomy/role/DisclosureContentsOfSignificantAccountsPropertyPlantAndEquipmentAdditionalInformation
895 Disclosure of detailed information about property, plant and equipment [table] Table

*

*

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896 Individual assets or cash-generating units [axis] Axis ifrs-full:IndividualAssetsOrCashgeneratingUnitsAxis
897 Entity's total for individual assets or cash-generating units [member] Member ifrs-full:EntitysTotalForIndividualAssetsOrCashgeneratingUnitsMember
898 Cash-generating units [member] Member ifrs-full:IndividualAssetsOrCashgeneratingUnitsMember
899 Disclosure of detailed information about property, plant and equipment [line items] LineItems ifrs-full:DisclosureOfPropertyPlantAndEquipmentLineItems
900 Recoverable amount of the CGU Concept (Monetary) As Of Debit ifrs-full:RecoverableAmountOfAssetOrCashgeneratingUnit
901 Impairment loss Concept (Monetary) For Period ifrs-full:ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipment
902 Total interest expense before capitalization of borrowing costs Concept (Monetary) For Period ifrs-full:InterestCostsIncurred
903 1058 - Disclosure - Contents of Significant Accounts - Details of Capitalized Borrowing Costs (Detail) Network

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904 Disclosure of detailed information about property, plant and equipment [table] Table

*

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 ifrs-full:DisclosureOfPropertyPlantAndEquipmentTable
905 Range [axis] Axis ifrs-full:RangeAxis
906 Ranges [member] Member ifrs-full:RangesMember
907 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
908 Top of range [member] Member ifrs-full:TopOfRangeMember
909 Disclosure of detailed information about property, plant and equipment [line items] LineItems ifrs-full:DisclosureOfPropertyPlantAndEquipmentLineItems
910 Total interest capitalized Concept (Monetary) For Period ifrs-full:InterestCostsCapitalised
911 Interest rates applied Concept (Percent) For Period ifrs-full:CapitalisationRateOfBorrowingCostsEligibleForCapitalisation
912 1059 - Disclosure - Contents of Significant Accounts - Intangible Assets (Detail) Network

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913 Disclosure of reconciliation of changes in intangible assets and goodwill [table] Table

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914 Classes of intangible assets and goodwill [axis] Axis ifrs-full:ClassesOfIntangibleAssetsAndGoodwillAxis
915 Intangible assets and goodwill [member] Member ifrs-full:IntangibleAssetsAndGoodwillMember
916 Goodwill [member] Member ifrs-full:GoodwillMember
917 Software [member] Member ifrs-full:ComputerSoftwareMember
918 Patent and technology license fee [member] Member ifrs-full:TechnologybasedIntangibleAssetsMember
919 Others [member] Member ifrs-full:OtherIntangibleAssetsMember
920 Carrying amount, accumulated depreciation, amortization and impairment and gross carrying amount [Axis] Axis ifrs-full:CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis
921 Carrying amount [member] Member ifrs-full:CarryingAmountMember
922 Cost [member] Member ifrs-full:GrossCarryingAmountMember
923 Accumulated depreciation, amortisation and impairment [member] Member ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember
924 Disclosure of reconciliation of changes in intangible assets and goodwill [line items] LineItems ifrs-full:DisclosureOfReconciliationOfChangesInIntangibleAssetsAndGoodwillLineItems
925 Beginning balance Concept (Monetary) As Of Debit ifrs-full:IntangibleAssetsAndGoodwill
926 Additions Concept (Monetary) For Period Debit ifrs-full:AdditionsOtherThanThroughBusinessCombinationsIntangibleAssetsOtherThanGoodwill
927 Amortization Concept (Monetary) For Period ifrs-full:AmortisationIntangibleAssetsOtherThanGoodwill
928 Disposals Concept (Monetary) For Period Credit ifrs-full:DisposalsIntangibleAssetsAndGoodwill
929 Disposal of subsidiaries Concept (Monetary) As Of Debit umc:DisposalGroupGoodwillAndIntangibleAssets
930 Reclassifications Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughTransfersAndOtherChangesIntangibleAssetsAndGoodwill
931 Exchange effect Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseThroughNetExchangeDifferencesIntangibleAssetsAndGoodwill
932 Ending balance Concept (Monetary) As Of Debit ifrs-full:IntangibleAssetsAndGoodwill
933 1060 - Disclosure - Contents of Significant Accounts - Amortization Amounts of Intangible Assets (Detail) Network

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

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935 Statement of comprehensive income, profit or loss location [axis] Axis umc:StatementOfComprehensiveIncomeProfitOrLossLocationAxis
936 Income Statement Location [Domain] Member us-gaap:IncomeStatementLocationDomain
937 Operating costs [member] Member umc:OperatingCostsMember
938 Operating expenses [member] Member umc:OperatingExpense1Member
939 Disclosure of detailed information about intangible assets [line items] LineItems ifrs-full:DisclosureOfIntangibleAssetsLineItems
940 Amortization amounts of intangible assets Concept (Monetary) For Period ifrs-full:AmortisationIntangibleAssetsOtherThanGoodwill
941 1061 - Disclosure - Contents of Significant Accounts - Short-Term Loans (Detail) Network

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942 Disclosure of detailed information about borrowings [table] Table

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 ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsTable
943 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
944 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
945 Unsecured bank loans [member] Member umc:UnsecuredBankLoansMember
946 Unsecured other loans [member] Member umc:UnsecuredOtherLoansMember
947 Range [axis] Axis ifrs-full:RangeAxis
948 Ranges [member] Member ifrs-full:RangesMember
949 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
950 Top of range [member] Member ifrs-full:TopOfRangeMember
951 Disclosure of detailed information about borrowings [line items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
952 Short-term loans Concept (Monetary) As Of Credit ifrs-full:ShorttermBorrowings
953 Interest rates applied Concept (Percent) As Of umc:ShorttermBorrowingsInterestRate
954 1062 - Disclosure - Contents of Significant Accounts - Short-Term Loans - Additional Information (Detail) Network

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955 Disclosure of detailed information about borrowings [table] Table

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956 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
957 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
958 Short term lines of credit [member] Member umc:ShortTermLinesOfCreditMember
959 Disclosure of detailed information about borrowings [line items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
960 Unused short-term lines of credit Concept (Monetary) As Of Credit ifrs-full:UndrawnBorrowingFacilities
961 1063 - Disclosure - Contents of Significant Accounts - Bonds Payable (Detail) Network

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962 Disclosure of detailed information about bonds [Table] Table

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963 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
964 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
965 Unsecured domestic bonds payable [member] Member umc:UnsecuredDomesticBondsPayableMember
966 Unsecured convertible bonds payable [member] Member umc:UnsecuredConvertibleBondsPayableMember
967 Carrying amount, accumulated depreciation, amortization and impairment and gross carrying amount [Axis] Axis ifrs-full:CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis
968 Carrying amount [member] Member ifrs-full:CarryingAmountMember
969 Cost [member] Member ifrs-full:GrossCarryingAmountMember
970 Discounts on bonds payable [member] Member umc:DiscountsOnBondsPayableMember
971 Disclosure of detailed information about bonds [Line Items] LineItems umc:DisclosureOfDetailedInformationAboutBondsLineItems
972 Bonds payable Concept (Monetary) As Of Credit ifrs-full:BondsIssued
973 Less: Current portion Concept (Monetary) As Of Credit ifrs-full:CurrentBondsIssuedAndCurrentPortionOfNoncurrentBondsIssued
974 Net Concept (Monetary) As Of Credit ifrs-full:NoncurrentPortionOfNoncurrentBondsIssued
975 1064 - Disclosure - Contents of Significant Accounts - Summary of Terms and Conditions of Bonds (Detail) Network

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976 Disclosure of detailed information about bonds [Table] Table

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977 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
978 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
979 Domestic unsecured corporate bonds maturing in June 2019 [member] Member umc:DomesticUnsecuredCorporateBondsMaturingInJune2019Member
980 Domestic unsecured corporate bonds maturing in March 2018 [member] Member umc:DomesticUnsecuredCorporateBondsMaturingInMarch2018Member
981 Domestic unsecured corporate bonds maturing in March 2020 [member] Member umc:DomesticUnsecuredCorporateBondsMaturingInMarch2020Member
982 Domestic unsecured corporate bonds maturing in June 2021 [member] Member umc:DomesticUnsecuredCorporateBondsMaturingInJune2021Member
983 Domestic unsecured corporate bonds maturing in June 2024 [member] Member umc:DomesticUnsecuredCorporateBondsMaturingInJune2024Member
984 Domestic unsecured corporate bonds maturing in march 2022 [member] Member umc:DomesticUnsecuredCorporateBondsMaturingInMarch2022Member
985 Domestic unsecured corporate bonds maturing in march 2024 [member] Member umc:DomesticUnsecuredCorporateBondsMaturingInMarch2024Member
986 Domestic unsecured corporate bonds maturing in october 2022 [member] Member umc:DomesticUnsecuredCorporateBondsMaturingInOctober2022Member
987 Domestic unsecured corporate bonds maturing in October 2024 [member] Member umc:DomesticUnsecuredCorporateBondsMaturingInOctober2024Member
988 Disclosure of detailed information about bonds [Line Items] LineItems umc:DisclosureOfDetailedInformationAboutBondsLineItems
989 Term Concept (Text/String) For Period ifrs-full:BorrowingsMaturity
990 Issuance date Concept (Text/String) For Period umc:BondIssuanceDate
991 Issued amount Concept (Monetary) As Of Credit ifrs-full:BondsIssued
992 Coupon rate Concept (Percent) As Of umc:BondsInterestRate
993 Repayment Concept (Text/String) For Period umc:BondsPayableRepaymentAndInterestPayableDescription
994 1065 - Disclosure - Contents of Significant Accounts - Bonds Payable - Additional Information (Detail) Network

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995 Disclosure of detailed information about bonds [Table] Table

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996 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
997 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
998 Currency linked zero coupon convertible bonds maturing on May 18, 2020 [member] Member umc:CurrencyLinkedZeroCouponConvertibleBondsMaturingOnMay182020Member
999 Range [axis] Axis ifrs-full:RangeAxis
1000 Ranges [member] Member ifrs-full:RangesMember
1001 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
1002 Disclosure of detailed information about bonds [Line Items] LineItems umc:DisclosureOfDetailedInformationAboutBondsLineItems
1003 Bonds issued amount Concept (Monetary) As Of Credit ifrs-full:BondsIssued
1004 Minimum holding period before issuer may redeem bonds Concept (xbrli:durationItemType) For Period umc:MinimumHoldingPeriodBeforeIssuerMayRedeemBond
1005 Per annum interest rate related to early redemption of bonds Concept (Percent) For Period umc:EarlyRedemptionPriceInterestRate
1006 Percentage of closing stock price to conversion price for early redemption of bonds Concept (Percent) For Period umc:PercentageOfClosingStockPriceToConversionPriceForEarlyRedemptionOfBonds
1007 Early Redemption Price, fixed exchange rate Concept (Decimal) As Of umc:EarlyRedemptionPriceFixedExchangeRate
1008 Percentage of principal amount that has already been converted, redeemed or repurchased and cancelled, where issuer may redeem the bonds Concept (Percent) For Period umc:PercentageOfPrincipalAmountThatHasAlreadyBeenConvertedRedeemedOrRepurchasedAndCancelledWhereIssuerMayRedeemTheBonds
1009 Percentage of principal amount, bond will be redeemable for early redemption Concept (Percent) For Period umc:PercentageOfPrincipalAmountBondWillBeRedeemableForEarlyRedemption
1010 Conversion price per share Concept (Share) As Of umc:ConversionPricePerShare
1011 Percentage of principal amount to redeem bonds on maturity date Concept (Percent) For Period umc:PercentageOfPrincipalAmountToRedeemBondsOnMaturityDate
1012 Value of the conversion right of the convertible bonds determined at issuance Concept (Monetary) As Of Credit umc:ValueOfTheConversionRightOfTheConvertibleBondsDeterminedAtIssuance
1013 Convertible bonds, issuance costs Concept (Monetary) For Period Credit umc:IssuanceCostsOfConvertibleBonds
1014 Effective interest rate on the liability component of the convertible bonds Concept (Percent) For Period umc:EffectiveInterestRateOnTheLiabilityComponentOfTheConvertibleBonds
1015 1066 - Disclosure - Contents of Significant Accounts - Details of Long-term Loans (Detail) Network

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*

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1016 Disclosure of detailed information about borrowings [table] Table

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1017 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
1018 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
1019 Secured long-term loan from mega international commercial bank (1) [member] Member umc:SecuredLongtermLoanFromMegaInternationalCommercialBank1Member
1020 Secured long-term loan from mega international commercial bank (2) [member] Member umc:SecuredLongtermLoanFromMegaInternationalCommercialBank2Member
1021 Secured long-term loan from Taiwan cooperative bank (1) [member] Member umc:SecuredLongtermLoanFromTaiwanCooperativeBank1Member
1022 Secured long-term loan from Taiwan cooperative bank (2) [member] Member umc:SecuredLongtermLoanFromTaiwanCooperativeBank2Member
1023 Secured long-term loan from Taiwan cooperative bank (3) [member] Member umc:SecuredLongtermLoanFromTaiwanCooperativeBank3Member
1024 Secured long-term loan from Taiwan cooperative bank (4) [member] Member umc:SecuredLongtermLoanFromTaiwanCooperativeBank4Member
1025 Secured long-term loan from Taiwan cooperative bank (5) [member] Member umc:SecuredLongtermLoanFromTaiwanCooperativeBank5Member
1026 Secured long-term loan from Taiwan cooperative bank (6) [member] Member umc:SecuredLongtermLoanFromTaiwanCooperativeBank6Member
1027 Secured long-term loan from Taiwan cooperative bank (7) [member] Member umc:SecuredLongtermLoanFromTaiwanCooperativeBank7Member
1028 Unsecured long-term loan from bank of Taiwan [member] Member umc:UnsecuredLongTermLoanFromBankOfTaiwanMember
1029 Unsecured syndicated loans from bank of Taiwan and 7 others [member] Member umc:UnsecuredSyndicatedLoansFromBankOfTaiwanAnd7OthersMember
1030 Unsecured long-term loan from mega international commercial bank [member] Member umc:UnsecuredLongtermLoanFromMegaInternationalCommercialBankMember
1031 Secured syndicated loans from China development bank and 6 others [member] Member umc:SecuredSyndicatedLoansFromChinaDevelopmentBankAnd6OthersMember
1032 Range [axis] Axis ifrs-full:RangeAxis
1033 Ranges [member] Member ifrs-full:RangesMember
1034 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
1035 Top of range [member] Member ifrs-full:TopOfRangeMember
1036 Carrying amount, accumulated depreciation, amortization and impairment and gross carrying amount [Axis] Axis ifrs-full:CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis
1037 Carrying amount [member] Member ifrs-full:CarryingAmountMember
1038 Cost [member] Member ifrs-full:GrossCarryingAmountMember
1039 Administrative expenses from syndicated loans [Member] Member umc:AdministrativeExpensesFromSyndicatedLoansMember
1040 Disclosure of detailed information about borrowings [line items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
1041 Long-term loans Concept (Monetary) As Of Credit ifrs-full:LoansReceived
1042 Less: Current portion Concept (Monetary) As Of Credit ifrs-full:CurrentLoansReceivedAndCurrentPortionOfNoncurrentLoansReceived
1043 Total Concept (Monetary) As Of Credit ifrs-full:NoncurrentPortionOfNoncurrentLoansReceived
1044 Redemption Concept (Text/String) For Period ifrs-full:DescriptionOfDetailsOfDefaultsDuringPeriodOfPrincipalInterestSinkingFundOrRedemptionTermsOfLoansPayable
1045 Interest rates applied Concept (Percent) As Of ifrs-full:BorrowingsInterestRate
1046 1067 - Disclosure - Contents of Significant Accounts - Long-Term Loans - Additional Information (Detail) Network

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*

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1047 Disclosure of detailed information about borrowings [table] Table

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1048 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
1049 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
1050 Unsecured syndicated loans from bank of Taiwan and 7 others [member] Member umc:UnsecuredSyndicatedLoansFromBankOfTaiwanAnd7OthersMember
1051 Secured syndicated loans from China development bank [member] Member umc:SecuredSyndicatedLoansFromChinaDevelopmentBankMember
1052 Range [axis] Axis ifrs-full:RangeAxis
1053 Ranges [member] Member ifrs-full:RangesMember
1054 Top of range [member] Member ifrs-full:TopOfRangeMember
1055 Legal Entity [Axis] Axis dei:LegalEntityAxis
1056 Entity [Domain] Member dei:EntityDomain
1057 HEJIAN TECHNOLOGY (SUZHOU) CO., LTD. (HJ) [member] Member umc:HejianTechnologySuzhouCoLtdMember
1058 Disclosure of detailed information about borrowings [line items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
1059 Endorsement Concept (Monetary) As Of Credit umc:EndorsementForOtherEntities
1060 1068 - Disclosure - Contents of Significant Accounts - Post-Employment Benefits - Additional Information (Detail) Network

*

*

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1061 Disclosure of defined benefit plans and defined contribution plans [Table] Table

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1062 Defined contribution plans [Axis] Axis umc:DefinedContributionPlansAxis
1063 Defined contribution plans [Domain] Member umc:DefinedContributionPlansDomain
1064 Defined contribution plan [member] Member umc:DefinedContributionPlanMember
1065 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
1066 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
1067 Defined benefit plan [member] Member umc:DefinedBenefitPlanMember
1068 Disclosure of defined benefit plans and defined contribution plans [Line Items] LineItems umc:DisclosureOfDefinedBenefitPlansAndDefinedContributionPlansLineItems
1069 Minimum percentage of employees' monthly salary or wages as monthly contributions to defined contribution plan Concept (Percent) For Period umc:MinimumPercentageOfMonthlySalaryOrWagesAsMonthlyContributionsToDefinedContributionPlan
1070 Pension expenses Concept (Monetary) For Period Debit ifrs-full:PostemploymentBenefitExpenseDefinedContributionPlans
1071 Percentages of employees' total monthly salaries and wages to pension fund Concept (Percent) For Period umc:PercentageOfEmployeesMonthlyWagesAndSalariesAsContributionsToDefinedBenefitPlan
1072 Pension expenses Concept (Monetary) For Period Debit ifrs-full:PostemploymentBenefitExpenseDefinedBenefitPlans
1073 Actual returns on plan assets Concept (Monetary) For Period Debit umc:ActualReturnOnPlanAssets
1074 Expected pension fund contribution in 2019 Concept (Monetary) For Period Credit ifrs-full:EstimateOfContributionsExpectedToBePaidToPlan
1075 Weighted-average durations of defined benefit obligation Concept (Decimal) For Period ifrs-full:WeightedAverageDurationOfDefinedBenefitObligation
1076 1069 - Disclosure - Contents of Significant Accounts - Movements in Present Value of Defined Benefit Obligation and Fair Value of Plan Assets (Detail) Network

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1077 Disclosure of net defined benefit liability (asset) [table] Table

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1078 Net defined benefit liability (asset) [axis] Axis ifrs-full:NetDefinedBenefitLiabilityAssetAxis
1079 Net defined benefit liability (asset) [member] Member ifrs-full:NetDefinedBenefitLiabilityAssetMember
1080 Present value of defined benefit obligation [member] Member ifrs-full:PresentValueOfDefinedBenefitObligationMember
1081 Plan assets [member] Member ifrs-full:PlanAssetsMember
1082 Disclosure of net defined benefit liability (asset) [line items] LineItems ifrs-full:DisclosureOfNetDefinedBenefitLiabilityAssetLineItems
1083 Beginning balance Concept (Monetary) As Of Credit ifrs-full:LiabilityAssetOfDefinedBenefitPlans
1084 Service cost Concept (Monetary) For Period Credit ifrs-full:CurrentServiceCostNetDefinedBenefitLiabilityAsset
1085 Interest income (cost) Concept (Monetary) For Period Credit ifrs-full:InterestExpenseIncomeNetDefinedBenefitLiabilityAsset
1086 Subtotal Concept (Monetary) For Period Credit umc:CurrentServiceCostAndInterestExpenseIncomeNetDefinedBenefitLiabilityAsset
1087 Contribution by employer Concept (Monetary) For Period Debit ifrs-full:ContributionsToPlanByEmployerNetDefinedBenefitLiabilityAsset
1088 Arising from changes in financial assumptions Concept (Monetary) For Period Debit ifrs-full:ActuarialGainsLossesArisingFromChangesInFinancialAssumptionsNetDefinedBenefitLiabilityAsset
1089 Experience adjustments Concept (Monetary) For Period Debit umc:ActuarialGainsLossesArisingFromChangesInExperienceAdjustmentsOnPlanLiabilitiesNetDefinedBenefitLiabilityAsset
1090 Subtotal Concept (Monetary) For Period Debit ifrs-full:GainLossOnRemeasurementOfNetDefinedBenefitLiabilityAsset
1091 Benefits paid Concept (Monetary) For Period Debit ifrs-full:PaymentsFromPlanNetDefinedBenefitLiabilityAsset
1092 Return on plan assets, excluding amounts included in interest income Concept (Monetary) For Period Debit ifrs-full:ReturnOnPlanAssetsNetDefinedBenefitLiabilityAsset
1093 Other Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughOtherChangesNetDefinedBenefitLiabilityAsset
1094 Ending balance Concept (Monetary) As Of Credit ifrs-full:LiabilityAssetOfDefinedBenefitPlans
1095 1070 - Disclosure - Contents of Significant Accounts - Defined Benefit Plan Recognized on the Consolidated Balance Sheets (Detail) Network

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1096 Implied Table Table

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*

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1097 Disclosure of defined benefit plans [abstract] Abstract ifrs-full:DisclosureOfDefinedBenefitPlansAbstract
1098 Present value of the defined benefit obligation Concept (Monetary) As Of Credit ifrs-full:DefinedBenefitObligationAtPresentValue
1099 Fair value of plan assets Concept (Monetary) As Of Debit ifrs-full:PlanAssetsAtFairValue
1100 Funded status Concept (Monetary) As Of Debit ifrs-full:SurplusDeficitInPlan
1101 Net defined benefit liabilities, noncurrent recognized on the consolidated balance sheets Concept (Monetary) As Of Credit ifrs-full:NoncurrentRecognisedLiabilitiesDefinedBenefitPlan
1102 1071 - Disclosure - Contents of Significant Accounts - Major Categories of Plan Assets as a Percentage of Fair Value of the Total Plan Assets (Detail) Network

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1103 Implied Table Table

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1104 Disclosure of fair value of plan assets [abstract] Abstract ifrs-full:DisclosureOfFairValueOfPlanAssetsAbstract
1105 Cash Concept (Percent) As Of umc:PercentageOfCashInThePlanAssets
1106 Equity instruments Concept (Percent) As Of umc:PercentageOfEquityInstrumentsInThePlanAssets
1107 Debt instruments Concept (Percent) As Of umc:PercentageOfDebtInstrumentsInThePlanAssets
1108 Others Concept (Percent) As Of umc:PercentageOfOtheRassetsInThePlanAssets
1109 1072 - Disclosure - Contents of Significant Accounts - Principal Underlying Actuarial Assumptions (Detail) Network

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*

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1110 Implied Table Table

*

*

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1111 Disclosure of defined benefit plans [abstract] Abstract ifrs-full:DisclosureOfDefinedBenefitPlansAbstract
1112 Discount rate Concept (Percent) As Of ifrs-full:ActuarialAssumptionOfDiscountRates
1113 Rate of future salary increase Concept (Percent) As Of ifrs-full:ActuarialAssumptionOfExpectedRatesOfSalaryIncreases
1114 1073 - Disclosure - Contents of Significant Accounts - Expected Future Benefit Payments (Detail) Network

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*

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1115 Disclosure of defined benefit plans [table] Table

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1116 Maturity [axis] Axis ifrs-full:MaturityAxis
1117 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
1118 Not later than one year [member] Member ifrs-full:NotLaterThanOneYearMember
1119 Later than one year and not later than two years [member] Member ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMember
1120 Later than two years and not later than three years [member] Member ifrs-full:LaterThanTwoYearsAndNotLaterThanThreeYearsMember
1121 Later than three years and not later than four years [member] Member ifrs-full:LaterThanThreeYearsAndNotLaterThanFourYearsMember
1122 Later than four years and not later than five years [member] Member ifrs-full:LaterThanFourYearsAndNotLaterThanFiveYearsMember
1123 Later than five years [member] Member ifrs-full:LaterThanFiveYearsMember
1124 Disclosure of defined benefit plans [line items] LineItems ifrs-full:DisclosureOfDefinedBenefitPlansLineItems
1125 Expected future benefit payments Concept (Monetary) For Period Credit umc:ExpectedFutureBenefitPaymentsOfDefinedBenefitPlan
1126 1074 - Disclosure - Contents of Significant Accounts - Sensitivity Analysis (Detail) Network

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*

 http://www.umc.com/taxonomy/role/DisclosureContentsOfSignificantAccountsSensitivityAnalysis
1127 Disclosure of sensitivity analysis for actuarial assumptions [table] Table

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*

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1128 Actuarial assumptions [axis] Axis ifrs-full:ActuarialAssumptionsAxis
1129 Actuarial assumptions [member] Member ifrs-full:ActuarialAssumptionsMember
1130 Discount rate [member] Member ifrs-full:ActuarialAssumptionOfDiscountRatesMember
1131 Rate of future salary increase [member] Member ifrs-full:ActuarialAssumptionOfExpectedRatesOfSalaryIncreasesMember
1132 Disclosure of sensitivity analysis for actuarial assumptions [line items] LineItems ifrs-full:DisclosureOfSensitivityAnalysisForActuarialAssumptionsLineItems
1133 Percentage increase in actuarial assumptions Concept (Percent) As Of ifrs-full:PercentageOfReasonablyPossibleIncreaseInActuarialAssumption
1134 Decrease (increase) in defined benefit obligation due to 0.5% increase in actuarial assumptions Concept (Monetary) As Of Credit ifrs-full:IncreaseDecreaseInDefinedBenefitObligationDueToReasonablyPossibleIncreaseInActuarialAssumption
1135 Percentage decrease in actuarial assumptions Concept (Percent) As Of ifrs-full:PercentageOfReasonablyPossibleDecreaseInActuarialAssumption
1136 Decrease (increase) in defined benefit obligation due to 0.5% decrease in actuarial assumptions Concept (Monetary) As Of Credit ifrs-full:IncreaseDecreaseInDefinedBenefitObligationDueToReasonablyPossibleDecreaseInActuarialAssumption
1137 1075 - Disclosure - Contents of Significant Accounts - Deferred Government Grants (Detail) Network

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*

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1138 Implied Table Table

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1139 Miscellaneous liabilities [abstract] Abstract ifrs-full:MiscellaneousLiabilitiesAbstract
1140 Beginning balance Concept (Monetary) As Of Credit ifrs-full:GovernmentGrants
1141 Arising during the period Concept (Monetary) For Period Debit ifrs-full:ProceedsFromGovernmentGrantsClassifiedAsInvestingActivities
1142 Other operating income Concept (Monetary) For Period Credit umc:AmortizationOfDeferredGovernmentGrants
1143 Exchange effect Concept (Monetary) For Period Credit umc:IncreaseDecreaseThroughNetExchangeDifferencesGovernmentGrants
1144 Ending balance Concept (Monetary) As Of Credit ifrs-full:GovernmentGrants
1145 Current Concept (Monetary) As Of Credit ifrs-full:CurrentGovernmentGrants
1146 Noncurrent Concept (Monetary) As Of Credit ifrs-full:NoncurrentGovernmentGrants
1147 Total Concept (Monetary) As Of Credit ifrs-full:GovernmentGrants
1148 1076 - Disclosure - Contents of Significant Accounts - Equity - Summary of Refund Liabilities (Detail) Network

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*

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1149 Implied Table Table

*

*

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1150 Disclosure of refund liability [abstract] Abstract umc:DisclosureOfRefundLiabilityAbstract
1151 Refund liabilities Concept (Monetary) As Of Credit umc:RefundLiabilities
1152 1077 - Disclosure - Contents of Significant Accounts - Equity - Additional Information (Detail) Network

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*

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1153 Disclosure of classes of share capital [table] Table

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*

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1154 Range [axis] Axis ifrs-full:RangeAxis
1155 Ranges [member] Member ifrs-full:RangesMember
1156 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
1157 Top of range [member] Member ifrs-full:TopOfRangeMember
1158 Classes of share capital [axis] Axis ifrs-full:ClassesOfShareCapitalAxis
1159 Share capital [member] Member ifrs-full:ClassesOfShareCapitalMember
1160 American depositary shares [member] Member umc:AmericanDepositarySharesMember
1161 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
1162 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
1163 FORTUNE VENTURE CAPITAL CORP. (FORTUNE) [member] Member umc:FortuneVentureCapitalCorpMember
1164 Associates [axis] Axis ifrs-full:SignificantInvestmentsInAssociatesAxis
1165 Entity's total for associates [member] Member ifrs-full:EntitysTotalForAssociatesMember
1166 HSUN CHIEH INVESTMENT CO., LTD. [member] Member umc:HsunChiehInvestmentCoLtdMember
1167 YANN YUAN INVESTMENT CO., LTD. [member] Member umc:YannYuanInvestmentCoLtdMember
1168 Disclosure of classes of share capital [line items] LineItems ifrs-full:DisclosureOfClassesOfShareCapitalLineItems
1169 Shares authorized Concept (Shares) As Of ifrs-full:NumberOfSharesAuthorised
1170 Shares issued Concept (Shares) As Of ifrs-full:NumberOfSharesIssued
1171 Shares par value Concept (Share) As Of ifrs-full:ParValuePerShare
1172 Number of American Depositary Shares traded on NYSE Concept (Shares) As Of umc:NumberOfAmericanDepositarySharesIssued
1173 Number of common shares represented by issued American Depositary Shares Concept (Shares) As Of umc:NumberOfCommonSharesRepresentedByIssuedAmericanDepositaryShares
1174 Number of common shares represented by 1 ADS Concept (Shares) As Of umc:NumberOfCommonSharesRepresentedByADSs
1175 Treasury stock cancelled Concept (Shares) For Period umc:NumberOfTreasurySharesCancelled
1176 Maximum percentage of total shares of treasury stock on issued stock as per Securities and Exchange Law of the R.O.C Concept (Percent) For Period umc:MaximumRegulatoryPercentageOfTreasuryStockOnIssuedStock
1177 Number of shares in entity held by its subsidiaries or associates Concept (Shares) As Of ifrs-full:SharesInEntityHeldByEntityOrByItsSubsidiariesOrAssociates
1178 Closing prices of UMC's stock Concept (Share) As Of umc:StockPricePerShare
1179 Percentage of legal reserve Concept (Percent) For Period umc:PercentageOfLegalReserve
1180 Percentage of cash dividend on dividend distribution Concept (Percent) For Period umc:CashDividendPercentageOnDividendDistribution
1181 Percentage of stock dividend on dividend distribution Concept (Percent) For Period umc:StockDividendPercentageOnDividendDistribution
1182 Cash dividends Concept (Share) For Period ifrs-full:DividendsPaidOrdinarySharesPerShare
1183 1078 - Disclosure - Contents of Significant Accounts - Purpose for Repurchase and Changes in Treasury Stock (Detail) Network

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*

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1184 Disclosure of classes of share capital [table] Table

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*

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1185 Timing of transfer of goods or services [axis] Axis ifrs-full:TimingOfTransferOfGoodsOrServicesAxis
1186 Timing of transfer of goods or services [member] Member ifrs-full:TimingOfTransferOfGoodsOrServicesMember
1187 Transfer to employees [member] Member umc:TransferToEmployeesMember
1188 Maintain credit and stockholders' rights and interests [member] Member umc:MaintainCreditAndStockholdersRightsAndInterestsMember
1189 Disclosure of classes of share capital [line items] LineItems ifrs-full:DisclosureOfClassesOfShareCapitalLineItems
1190 Beginning balance Concept (Shares) As Of umc:TreasurySharesHeld
1191 Increase Concept (Shares) For Period umc:IncreaseInTreasurySharesHeld
1192 Decrease Concept (Shares) For Period umc:DecreaseInTreasurySharesHeld
1193 Ending balance Concept (Shares) As Of umc:TreasurySharesHeld
1194 1079 - Disclosure - Contents of Significant Accounts - Details of Distribution (Detail) Network

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*

 http://www.umc.com/taxonomy/role/DisclosureContentsOfSignificantAccountsDetailsOfDistribution
1195 Disclosure of equity [Table] Table

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*

 umc:DisclosureOfEquityTable
1196 Components of equity [axis] Axis ifrs-full:ComponentsOfEquityAxis
1197 Equity [member] Member ifrs-full:EquityMember
1198 Legal Reserve [Member] Member umc:LegalReserve1Member
1199 Special Reserve [member] Member umc:SpecialReserveMember
1200 Cash dividends [member] Member umc:CashDividendMember
1201 Disclosure of equity [Line Items] LineItems umc:DisclosureOfEquityLineItems
1202 Appropriation of earnings Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughTransferToStatutoryReserve
1203 Appropriation of earnings, Cash dividends Concept (Monetary) For Period Debit ifrs-full:DividendsRecognisedAsDistributionsToOwnersOfParent
1204 Cash dividends Concept (Share) For Period ifrs-full:DividendsPaidOrdinarySharesPerShare
1205 1080 - Disclosure - Contents of Significant Accounts - Non-controlling Interests (Detail) Network

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*

 http://www.umc.com/taxonomy/role/DisclosureContentsOfSignificantAccountsNoncontrollingInterests
1206 Implied Table Table

*

*

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1207 Equity [abstract] Abstract ifrs-full:EquityAbstract
1208 Beginning balance Concept (Monetary) As Of Credit ifrs-full:NoncontrollingInterests
1209 Impact of retroactive applications Concept (Monetary) For Period Credit umc:CumulativeEffectAdjustmentOfAdoptingNewAccountingPrincipleOnNoncontrollingInterests
1210 Adjusted beginning balance Concept (Monetary) As Of Credit umc:AdjustedBeginningBalanceOfNoncontrollingInterestsAfterAdoptingNewAccountingPrinciple
1211 Net loss Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToNoncontrollingInterests
1212 Other comprehensive income (loss) Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeAttributableToNoncontrollingInterests
1213 Changes in subsidiaries' ownership Concept (Monetary) For Period Credit umc:NoncontrollingInterestsChangesInSubsidiariesOwnership
1214 Disposal of subsidiaries Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughDisposalOfSubsidiary
1215 Derecognition of the non-controlling interests Concept (Monetary) For Period Credit umc:NoncontrollingInterestsDerecognitionOfNoncontrollingInterests
1216 Ending balance Concept (Monetary) As Of Credit ifrs-full:NoncontrollingInterests
1217 1081 - Disclosure - Contents of Significant Accounts - Share-Based Payment - Additional Information (Detail) Network

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*

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1218 Disclosure of terms and conditions of share-based payment arrangement [table] Table

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*

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1219 Range [axis] Axis ifrs-full:RangeAxis
1220 Ranges [member] Member ifrs-full:RangesMember
1221 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
1222 Top of range [member] Member ifrs-full:TopOfRangeMember
1223 Disclosure of terms and conditions of share-based payment arrangement [line items] LineItems ifrs-full:DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems
1224 Number of treasury shares to employees Concept (Shares) For Period umc:NumberOfTreasurySharesSoldToEmployees
1225 Grant date quoted market price per share Concept (Share) For Period umc:TreasuryStockGrantDateQuotedMarketPricePerShare
1226 Vesting period Concept (xbrli:durationItemType) For Period umc:SharebasedPaymentsVestingPeriod
1227 Compensation expenses Concept (Monetary) For Period Debit ifrs-full:ExpenseFromSharebasedPaymentTransactionsWithEmployees
1228 1082 - Disclosure - Contents of Significant Accounts - Operating Revenues (Detail) Network

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*

 http://www.umc.com/taxonomy/role/DisclosureContentsOfSignificantAccountsOperatingRevenues
1229 Implied Table Table

*

*

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1230 Revenue [abstract] Abstract ifrs-full:RevenueAbstract
1231 Sale of goods Concept (Monetary) For Period Credit ifrs-full:RevenueFromSaleOfGoods
1232 Royalty Concept (Monetary) For Period Credit ifrs-full:RevenueFromRoyalties
1233 Mask tooling Concept (Monetary) For Period Credit ifrs-full:RevenueFromRenderingOfServices
1234 Others Concept (Monetary) For Period Credit ifrs-full:OtherRevenue
1235 Operating revenues Concept (Monetary) For Period Credit ifrs-full:Revenue
1236 1083 - Disclosure - Contents of Significant Accounts - Summary of Disaggregation of Revenue by Geography (Detail) Network

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*

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1237 Disclosure of Geographical Areas [Table] Table

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*

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1238 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
1239 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
1240 Taiwan [member] Member country:TW
1241 Singapore [member] Member country:SG
1242 China (includes Hong Kong) [member] Member umc:ChinaIncludesHongKongMember
1243 Japan [member] Member country:JP
1244 USA [member] Member country:US
1245 Europe [member] Member umc:Europe1Member
1246 Others [member] Member umc:AllOtherCountriesMember
1247 Disclosure of Geographical Areas [Line Items] LineItems ifrs-full:DisclosureOfGeographicalAreasLineItems
1248 Operating revenues Concept (Monetary) For Period Credit ifrs-full:Revenue
1249 1084 - Disclosure - Contents of Significant Accounts - Summary of Disaggregation of Revenue by Product (Detail) Network

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1250 Disclosure of Geographical Areas [Table] Table

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1251 Products and services [axis] Axis ifrs-full:ProductsAndServicesAxis
1252 Products and services [member] Member ifrs-full:ProductsAndServicesMember
1253 Wafer [member] Member umc:WaferMember
1254 Other products [member] Member umc:OtherProductsMember
1255 Disclosure Of Products [Line Items] LineItems umc:DisclosureOfProductsLineItems
1256 Revenue from contracts with customers Concept (Monetary) For Period Credit ifrs-full:RevenueFromContractsWithCustomers
1257 1085 - Disclosure - Contents of Significant Accounts - Summary of Disaggregation of Revenue by Operating Segments (Detail) Network

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*

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1258 Disclosure of disaggregation of revenue from contracts with customers [table] Table

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*

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1260 Segments [member] Member ifrs-full:SegmentsMember
1261 Wafer fabrication [member] Member umc:WaferFabricationSegmentMember
1262 New business [member] Member umc:NewBusinessMember
1263 Sub total [member] Member umc:SubTotalMember
1264 Adjustments And Eliminations [member] Member umc:AdjustmentsAndEliminationsMember
1265 Timing of transfer of goods or services [axis] Axis ifrs-full:TimingOfTransferOfGoodsOrServicesAxis
1266 Timing of transfer of goods or services [member] Member ifrs-full:TimingOfTransferOfGoodsOrServicesMember
1267 Goods or services transferred at point in time [member] Member ifrs-full:GoodsOrServicesTransferredAtPointInTimeMember
1268 Goods or services transferred over time [member] Member ifrs-full:GoodsOrServicesTransferredOverTimeMember
1269 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
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1271 Taiwan [member] Member country:TW
1272 Singapore [member] Member country:SG
1273 China (includes Hong Kong) [member] Member country:CN
1274 Japan [member] Member country:JP
1275 USA [member] Member country:US
1276 Europe [member] Member umc:Europe1Member
1277 Other Countries [member] Member umc:OtherCountriesMember
1278 Disclosure of disaggregation of revenue from contracts with customers [line items] LineItems ifrs-full:DisclosureOfDisaggregationOfRevenueFromContractsWithCustomersLineItems
1279 Revenue from contracts with customers Concept (Monetary) For Period Credit ifrs-full:RevenueFromContractsWithCustomers
1280 Revenue from contracts with customers Concept (Monetary) For Period Credit ifrs-full:RevenueFromContractsWithCustomers
1281 1086 - Disclosure - Contents of Significant Accounts - Summary of Balances of Contract Assets and Contract Liabilities (Detail) Network

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*

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1282 Disclosure of disaggregation of revenue from contracts with customers [table] Table

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1284 Products and services [member] Member ifrs-full:ProductsAndServicesMember
1285 Sales of Goods and Services [member] Member umc:SalesOfGoodsAndServicesMember
1286 Loss allowance [member] Member umc:AdjustmentInLossAllowanceMember
1287 Disclosure of balances of contract assets and contract liabilities [line items] LineItems umc:DisclosureOfBalancesOfContractAssetsAndContractLiabilitiesLineItems
1288 Contract assets, current Concept (Monetary) As Of Debit ifrs-full:CurrentContractAssets
1289 Contract assets, current Differences Concept (Monetary) For Period Debit umc:IncreaseDecreaseInContractAssetsCurrent
1290 Contract liabilities, current Concept (Monetary) As Of Credit ifrs-full:CurrentContractLiabilities
1291 Contract liabilities, current Differences Concept (Monetary) For Period Credit umc:IncreaseDecreaseInContractLiabilitiesCurrent
1292 1087 - Disclosure - Contents of Significant Accounts - Operating Revenues - Additional Information (Detail) Network

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*

 http://www.umc.com/taxonomy/role/DisclosureContentsOfSignificantAccountsOperatingRevenuesAdditionalInformation
1293 Implied Table Table

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1294 Disclosure of additional information about revenue [Abstract] Abstract umc:DisclosureOfAdditionalInformationAboutRevenueAbstract
1295 Revenue that was included in contract liability balance at beginning of period Concept (Monetary) For Period Credit ifrs-full:RevenueThatWasIncludedInContractLiabilityBalanceAtBeginningOfPeriod
1296 Transaction price allocated to unsatisfied performance obligations Concept (Monetary) As Of Credit ifrs-full:TransactionPriceAllocatedToRemainingPerformanceObligations
1297 Asset recognized from the cost to fulfill a contract with customer Concept (Monetary) As Of Debit ifrs-full:AssetsRecognisedFromCostsToObtainOrFulfilContractsWithCustomers
1298 1088 - Disclosure - Contents of Significant Accounts - Operating Costs and Expenses (Detail) Network

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*

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1299 Disclosure of Operating Costs and Expenses [Table] Table

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1301 Income Statement Location [Domain] Member us-gaap:IncomeStatementLocationDomain
1302 Operating costs [member] Member umc:OperatingCostsMember
1303 Operating expenses [member] Member umc:OperatingExpense1Member
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1305 Salaries Concept (Monetary) For Period Debit ifrs-full:WagesAndSalaries
1306 Labor and health insurance Concept (Monetary) For Period Debit ifrs-full:InsuranceExpense
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1310 Amortization Concept (Monetary) For Period Debit ifrs-full:AmortisationExpense
1311 1089 - Disclosure - Contents of Significant Accounts - Operating Costs and Expenses - Additional Information (Detail) Network

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1312 Disclosure of Operating Costs and Expenses [Table] Table

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1316 Top of range [member] Member ifrs-full:TopOfRangeMember
1317 Disclosure Of Operating Costs And Expenses [Line Items] LineItems umc:DisclosureOfOperatingCostsAndExpensesLineItems
1318 Allocated profit percentage for employees' compensation Concept (Percent) For Period umc:AllocatedProfitPercentageForEmployeesCompensation
1319 Allocated profit percentage for directors' compensation Concept (Percent) For Period umc:AllocatedProfitPercentageForDirectorsCompensation
1320 1090 - Disclosure - Contents of Significant Accounts - Details of Distribution of Employees' Compensation and Directors' Compensation (Detail) Network

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*

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1321 Implied Table Table

*

*

 implied:Table
1322 Analysis of income and expense [abstract] Abstract ifrs-full:AnalysisOfIncomeAndExpenseAbstract
1323 Employees' compensation - Cash Concept (Monetary) For Period Debit ifrs-full:ShorttermEmployeeBenefitsExpense
1324 Directors' compensation Concept (Monetary) For Period Debit ifrs-full:DirectorsRemunerationExpense
1325 1091 - Disclosure - Contents of Significant Accounts - Net Other Operating Income and Expenses (Detail) Network

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*

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1326 Implied Table Table

*

*

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1327 Analysis of income and expense [abstract] Abstract ifrs-full:AnalysisOfIncomeAndExpenseAbstract
1328 Gain on disposal of property, plant and equipment Concept (Monetary) For Period Credit ifrs-full:GainsOnDisposalsOfPropertyPlantAndEquipment
1329 Impairment loss of property, plant and equipment Concept (Monetary) For Period ifrs-full:ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipment
1330 Government grants Concept (Monetary) For Period Credit ifrs-full:RevenueFromGovernmentGrants
1331 Others Concept (Monetary) For Period Credit umc:MiscellaneousOtherOperatingIncomeExpense
1332 Total Concept (Monetary) For Period Credit ifrs-full:OtherOperatingIncomeExpense
1333 1092 - Disclosure - Contents of Significant Accounts - Non-Operating Income and Expenses (Detail) Network

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*

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1334 Disclosure of detailed information about financial instruments [table] Table

*

*

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1336 Assets [member] Member ifrs-full:ClassesOfAssetsMember
1337 Investments accounted for under the equity method [Member] Member ifrs-full:InvestmentsAccountedForUsingEquityMethodMember
1338 Categories of financial assets [axis] Axis ifrs-full:CategoriesOfFinancialAssetsAxis
1339 Financial assets, category [member] Member ifrs-full:FinancialAssetsCategoryMember
1340 Available-for-sale financial assets [member] Member ifrs-full:FinancialAssetsAvailableforsaleCategoryMember
1341 Financial assets measured at cost [member] Member ifrs-full:FinancialAssetsAtAmortisedCostCategoryMember
1342 Disclosure of detailed information about financial instruments [line items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsLineItems
1343 Gain (loss) on valuation of financial assets and liabilities at fair value through profit or loss Concept (Monetary) For Period Credit umc:GainOnFinancialAssetsLiabilitiesAtFairValueThroughProfitOrLoss
1344 Impairment loss Concept (Monetary) For Period Debit ifrs-full:ImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLoss
1345 Gain (loss) on disposal of investments Concept (Monetary) For Period Credit ifrs-full:GainsOnDisposalsOfInvestments
1346 Others Concept (Monetary) For Period Credit umc:OtherGainsAndLossesCategorizedAsOtherNonOperatingIncomeAndExpenses
1347 Total other gains and losses Concept (Monetary) For Period Credit ifrs-full:OtherGainsLosses
1348 Interest expenses, bonds payable Concept (Monetary) For Period Debit ifrs-full:InterestExpenseOnBonds
1349 Interest expenses, bank loans Concept (Monetary) For Period Debit ifrs-full:InterestExpenseOnBankLoansAndOverdrafts
1350 Interest expenses, others Concept (Monetary) For Period Debit ifrs-full:InterestExpenseOnOtherFinancialLiabilities
1351 Financial expenses Concept (Monetary) For Period Debit ifrs-full:OtherFinanceCost
1352 Total finance costs Concept (Monetary) For Period Debit ifrs-full:FinanceCosts
1353 1093 - Disclosure - Contents of Significant Accounts - Components of Other Comprehensive Income (Loss) (Detail) Network

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*

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1354 Implied Table Table

*

*

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1355 Statement of changes in equity [abstract] Abstract ifrs-full:StatementOfChangesInEquityAbstract
1356 Remeasurements of defined benefit pension plans , Arising during the period Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans
1357 Unrealized gains or losses on financial assets at fair value through other comprehensive income, Arising during the period Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeBeforeTax
1358 Gains or losses on hedging instruments which will not be reclassified subsequently to profit or loss, Arising during the period Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnCashFlowHedgesBeforeTax
1359 Share of other comprehensive income (loss) of associates and joint ventures which will not be reclassified subsequently to profit or loss, Arising during the period Concept (Monetary) For Period Credit ifrs-full:ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillNotBeReclassifiedToProfitOrLossBeforeTax
1360 Exchange differences on translation of foreign operations, Arising during the period Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnExchangeDifferencesOnTranslationBeforeTax
1361 Unrealized gains or losses on available-for-sale financial assets, Arising during the period Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnRemeasuringAvailableforsaleFinancialAssetsBeforeTax
1362 Share of other comprehensive income (loss) of associates and joint ventures which may be reclassified subsequently to profit or loss, Arising during the period Concept (Monetary) For Period Credit umc:ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodBeforeReclassificationToProfitOrLossBeforeTax
1363 Total other comprehensive income (loss), Arising during the period Concept (Monetary) For Period Credit umc:OtherComprehensiveIncomeBeforeReclassificationAndTax
1364 Exchange differences on translation of foreign operations, Reclassification adjustments during the period Concept (Monetary) For Period Debit ifrs-full:ReclassificationAdjustmentsOnExchangeDifferencesOnTranslationBeforeTax
1365 Unrealized gains or losses on available-for-sale financial assets, Reclassification adjustments during the period Concept (Monetary) For Period Debit ifrs-full:ReclassificationAdjustmentsOnAvailableforsaleFinancialAssetsBeforeTax
1366 Share of other comprehensive income (loss) of associates and joint ventures which may be reclassified subsequently to profit or loss, Reclassification adjustments during the period Concept (Monetary) For Period Debit umc:ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodReclassifiedToProfitOrLossBeforeTax
1367 Total other comprehensive income (loss), Reclassification adjustments during the period Concept (Monetary) For Period Debit umc:ReclassificationAdjustmentsOnOtherComprehensiveIncomeBeforeTax
1368 Remeasurements of defined benefit pension plans, Before tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeBeforeTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans
1369 Unrealized gains or losses on financial assets at fair value through other comprehensive income, Before tax Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeBeforeTax
1370 Gains or losses on hedging instruments which will not be reclassified subsequently to profit or loss, Before tax Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnCashFlowHedgesBeforeTax
1371 Share of other comprehensive income (loss) of associates and joint ventures which will not be reclassified subsequently to profit or loss, Before tax Concept (Monetary) For Period Credit ifrs-full:ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillNotBeReclassifiedToProfitOrLossBeforeTax
1372 Exchange differences on translation of foreign operations, Before tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeBeforeTaxExchangeDifferencesOnTranslation
1373 Unrealized gains or losses on available-for-sale financial assets, Before tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeBeforeTaxAvailableforsaleFinancialAssets
1374 Share of other comprehensive income (loss) of associates and joint ventures which may be reclassified subsequently to profit or loss, Before tax Concept (Monetary) For Period Credit ifrs-full:ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillBeReclassifiedToProfitOrLossBeforeTax
1375 Total other comprehensive income (loss), Before tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeBeforeTax
1376 Remeasurements of defined benefit pension plans, Income tax effect Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToRemeasurementsOfDefinedBenefitPlansOfOtherComprehensiveIncome
1377 Unrealized gains or losses on financial assets at fair value through other comprehensive income, Income tax effect Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToInvestmentsInEquityInstrumentsOfOtherComprehensiveIncome
1378 Gains or losses on hedging instruments which will not be reclassified subsequently to profit or loss, Income tax effect Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToCashFlowHedgesOfOtherComprehensiveIncome
1379 Share of other comprehensive income (loss) of associates and joint ventures which will not be reclassified subsequently to profit or loss, Income tax effect Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillNotBeReclassifiedToProfitOrLoss
1380 Exchange differences on translation of foreign operations, Income tax effect Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToExchangeDifferencesOnTranslationOfOtherComprehensiveIncome
1381 Unrealized gains or losses on available-for-sale financial assets,Income tax effect Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToAvailableforsaleFinancialAssetsOfOtherComprehensiveIncome
1382 Share of other comprehensive income (loss) of associates and joint ventures which may be reclassified subsequently to profit or loss, Income tax effect Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillBeReclassifiedToProfitOrLoss
1383 Total other comprehensive income (loss), Income tax effect Concept (Monetary) For Period ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncome
1384 Remeasurements of defined benefit pension plans, Net of tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeNetOfTaxGainsLossesOnRemeasurementsOfDefinedBenefitPlans
1385 Unrealized gains or losses on financial assets at fair value through other comprehensive income, Net of tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeNetOfTaxGainsLossesFromInvestmentsInEquityInstruments
1386 Gains or losses on hedging instruments which will not be reclassified subsequently to profit or loss, Net of tax Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnCashFlowHedgesNetOfTax
1387 Share of other comprehensive income (loss) of associates and joint ventures which will not be reclassified subsequently to profit or loss, Net of tax Concept (Monetary) For Period Credit ifrs-full:ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillNotBeReclassifiedToProfitOrLossNetOfTax
1388 Exchange differences on translation of foreign operations, Net of tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeNetOfTaxExchangeDifferencesOnTranslation
1389 Unrealized gains or losses on available-for-sale financial assets, Net of tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeNetOfTaxAvailableforsaleFinancialAssets
1390 Share of other comprehensive income (loss) of associates and joint ventures which may be reclassified subsequently to profit or loss, Net of tax Concept (Monetary) For Period Credit ifrs-full:ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillBeReclassifiedToProfitOrLossNetOfTax
1391 Total other comprehensive income (loss), net of tax Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncome
1392 1094 - Disclosure - Contents of Significant Accounts - Major Components of Income Tax Expense (Detail) Network

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*

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1393 Implied Table Table

*

*

 implied:Table
1394 Major components of tax expense (income) [abstract] Abstract ifrs-full:MajorComponentsOfTaxExpenseIncomeAbstract
1395 Current income tax expense (benefit): Abstract ifrs-full:CurrentTaxExpenseIncomeAndAdjustmentsForCurrentTaxOfPriorPeriodsAbstract
1396 Current income tax charge Concept (Monetary) For Period Debit ifrs-full:CurrentTaxExpenseIncome
1397 Adjustments in respect of current income tax of prior periods Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForCurrentTaxOfPriorPeriod
1398 Deferred income tax expense (benefit): Abstract ifrs-full:DeferredTaxExpenseIncomeAbstract
1399 Deferred income tax related to origination and reversal of temporary differences Concept (Monetary) For Period Debit ifrs-full:DeferredTaxExpenseIncomeRelatingToOriginationAndReversalOfTemporaryDifferences
1400 Deferred income tax related to recognition and derecognition of tax losses and unused tax credits Concept (Monetary) For Period Debit umc:DeferredTaxExpenseIncomeRelatingToRecognitionAndDerecognitionOfTaxLossesAndUnusedTaxCredits
1401 Deferred income tax related to changes in tax rates Concept (Monetary) For Period Debit ifrs-full:DeferredTaxExpenseIncomeRelatingToTaxRateChangesOrImpositionOfNewTaxes
1402 Adjustment of prior year's deferred income tax Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDeferredTaxOfPriorPeriods
1403 Deferred income tax arising from write-down or reversal of write-down of deferred tax assets Concept (Monetary) For Period Debit ifrs-full:DeferredTaxExpenseArisingFromWritedownOrReversalOfWritedownOfDeferredTaxAsset
1404 Income tax expense (benefit) recorded in profit or loses Concept (Monetary) For Period Debit ifrs-full:IncomeTaxExpenseContinuingOperations
1405 Income tax related to components of other comprehensive income (loss), Items that will not be reclassified subsequently to profit or loss Abstract ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLossAbstract
1406 Remeasurements of defined benefit pension plans Concept (Monetary) For Period Debit umc:IncomeTaxRelatingToRemeasurementsOfDefinedBenefitPlansOfOtherComprehensiveIncomeExcludingTheEffectOfChangesInTaxRates
1407 Unrealized gains or losses on financial assets at fair value through other comprehensive income Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncome
1408 Gains or losses on hedging instruments which will not be reclassified subsequently to profit or loss Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToCashFlowHedgesOfOtherComprehensiveIncome
1409 Share of other comprehensive income (loss) of associates and joint ventures which will not be reclassified subsequently to profit or loss Concept (Monetary) For Period Debit umc:IncomeTaxRelatingToShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillNotBeReclassifiedToProfitOrLossExcludingTheEffectOfChangesInTaxRates
1410 Deferred income tax related to changes in tax rates Concept (Monetary) For Period Debit umc:DeferredIncomeTaxRelatedToChangesInTaxRatesWillNotBeReclassifiedToProfitOrLoss
1411 Income tax related to items that will not be reclassified subsequently to profit or loss Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillNotBeReclassifiedToProfitOrLoss
1412 Income tax related to components of other comprehensive income (loss), Items that may be reclassified subsequently to profit or loss Abstract ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossAbstract
1413 Exchange differences on translation of foreign operations Concept (Monetary) For Period Debit umc:IncomeTaxRelatingToExchangeDifferencesOnTranslationOfOtherComprehensiveIncomeExcludingTheEffectOfChangesInTaxRates
1414 Unrealized gains or losses on available-for-sale financial assets Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToAvailableforsaleFinancialAssetsOfOtherComprehensiveIncome
1415 Share of other comprehensive income (loss) of associates and joint ventures which may be reclassified subsequently to profit or loss Concept (Monetary) For Period Debit umc:IncomeTaxRelatingToShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillBeReclassifiedToProfitOrLossExcludingTheEffectOfChangesInTaxRates
1416 Deferred income tax related to changes in tax rates Concept (Monetary) For Period Debit umc:DeferredIncomeTaxRelatedToChangesInTaxRatesReclassifiedToProfitOrLoss
1417 Income tax related to items that may be reclassified subsequently to profit or loss Concept (Monetary) For Period Debit ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLoss
1418 Deferred income tax recognized directly to equity Abstract ifrs-full:CurrentAndDeferredTaxRelatingToItemsChargedOrCreditedDirectlyToEquityAbstract
1419 Adjustments of changes in net assets of associates and joint ventures accounted for using equity method Concept (Monetary) For Period Debit umc:DeferredTaxRelatingToAdjustmentsOfChangesInNetAssetsOfAssociatesAndJointVenturesAccountedForUsingEquityMethodChargedOrCreditedDirectlyToEquity
1420 Deferred income tax related to changes in tax rates Concept (Monetary) For Period Debit umc:DeferredIncomeTaxRelatedToChangesInTaxRatesRecognizedDirectlyToEquity
1421 Income tax recognized directly to equity Concept (Monetary) For Period ifrs-full:DeferredTaxRelatingToItemsChargedOrCreditedDirectlyToEquity
1422 1095 - Disclosure - Contents of Significant Accounts - Reconciliation Between Income Tax Expense and Income Before Tax At UMC's Applicable Tax Rate (Detail) Network

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1423 Implied Table Table

*

*

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1424 Reconciliation of accounting profit multiplied by applicable tax rates [abstract] Abstract ifrs-full:ReconciliationOfAccountingProfitMultipliedByApplicableTaxRatesAbstract
1425 Income before tax Concept (Monetary) For Period Credit ifrs-full:ProfitLossBeforeTax
1426 At UMC's statutory income tax rate Concept (Monetary) For Period Debit ifrs-full:TaxExpenseIncomeAtApplicableTaxRate
1427 Adjustments in respect of current income tax of prior periods Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForCurrentTaxOfPriorPeriod
1428 Net change in loss carry-forward and investment tax credits Concept (Monetary) For Period Debit umc:NetChangeInLossCarryForwardAndInvestmentTaxCredits
1429 Adjustment of deferred tax assets/liabilities for write-downs/reversals and different jurisdictional tax rates Concept (Monetary) For Period Debit umc:AdjustmentsForDeferredTaxAssetsAndLiabilitiesForWritedownsReversalAndDifferentJurisdictionalTaxRates
1430 Tax effect of non-taxableincome and non-deductibleexpenses: Abstract umc:TaxEffectOfNonTaxableIncomeAndNonDeductibleExpensesAbstract
1431 Tax exempt income Concept (Monetary) For Period Debit umc:TaxEffectOfNonTaxableIncomeAndNonDeductibleExpensesTaxExemptIncome
1432 Investment gain Concept (Monetary) For Period Debit umc:TaxEffectOfNonTaxableIncomeAndNonDeductibleExpensesInvestmentGain
1433 Dividend income Concept (Monetary) For Period Debit umc:TaxEffectOfNonTaxableIncomeAndNonDeductibleExpensesDividendIncome
1434 Others Concept (Monetary) For Period Debit umc:TaxEffectOfNonTaxableIncomeAndNonDeductibleExpensesOthers
1435 Basic tax Concept (Monetary) For Period Debit umc:IncomeTaxExpenseBasicTax
1436 Estimated income tax on unappropriated earnings Concept (Monetary) For Period Debit umc:EstimatedIncomeTaxOnUnappropriatedEarnings
1437 Deferred income tax related to changes in tax rates Concept (Monetary) For Period Debit ifrs-full:DeferredTaxExpenseIncomeRelatingToTaxRateChangesOrImpositionOfNewTaxes
1438 Effect of different tax rates applicable to UMC and its subsidiaries Concept (Monetary) For Period Debit umc:TaxEffectOfDifferentTaxRatesApplicableToSubsidiaries
1439 Taxes withheld in other jurisdictions Concept (Monetary) For Period Debit ifrs-full:TaxEffectOfForeignTaxRates
1440 Others Concept (Monetary) For Period Debit ifrs-full:OtherTaxEffectsForReconciliationBetweenAccountingProfitAndTaxExpenseIncome
1441 Income tax expense (benefit) recorded in profit or loses Concept (Monetary) For Period Debit ifrs-full:IncomeTaxExpenseContinuingOperations
1442 1096 - Disclosure - Contents of Significant Accounts - Significant Components of Deferred Income Tax Assets and Liabilities (Detail) Network

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1443 Disclosure Of Deferred Taxes [Table] Table

*

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 umc:DisclosureOfDeferredTaxesTable
1444 Assets and liabilities [axis] Axis ifrs-full:AssetsAndLiabilitiesAxis
1445 Assets and liabilities [member] Member ifrs-full:AssetsAndLiabilitiesMember
1446 Depreciation [member] Member ifrs-full:AccumulatedDepreciationAndAmortisationMember
1447 Loss carry-forward [member] Member ifrs-full:UnusedTaxLossesMember
1448 Defined benefit plan [member] Member umc:DefinedBenefitPlanMember
1449 Refund liabilities [member] Member umc:RefundLiabilitiesMember
1450 Allowance for sales returns and discounts [member] Member umc:AllowanceForSalesReturnsAndDiscountsMember
1451 Allowance for inventory valuation losses [member] Member umc:AllowanceForInventoryValuationLossesMember
1452 Investment loss [member] Member umc:InvestmentLossMember
1453 Unrealized profit on intercompany sales [member] Member umc:UnrealizedProfitOnIntercompanySalesMember
1454 Investment tax credits [member] Member umc:InvestmentTaxCreditsMember
1455 Deferred revenue [member] Member umc:DeferredRevenueMember
1456 Others [member] Member ifrs-full:OtherTemporaryDifferencesMember
1457 Unrealized exchange gain (losses) [member] Member ifrs-full:UnrealisedForeignExchangeGainsLossesMember
1458 Investment gain [member] Member umc:InvestmentGainMember
1459 Convertible bond option [member] Member umc:ConvertibleBondOptionMember
1460 Amortizable assets [member] Member umc:AmortizableAssetsMember
1461 Disclosure Of Deferred Taxes [Line Items] LineItems umc:DisclosureOfDeferredTaxesLineItems
1462 Deferred income tax assets Concept (Monetary) As Of Debit ifrs-full:DeferredTaxAssets
1463 Deferred income tax liabilities Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilities
1464 Net deferred income tax assets Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilityAsset
1465 1097 - Disclosure - Contents of Significant Accounts - Movement of Deferred Tax (Detail) Network

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1466 Changes in deferred tax assets and liabilities [Table] Table

*

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 umc:ChangesInDeferredTaxAssetsAndLiabilitiesTable
1467 Retrospective application and retrospective restatement [axis] Axis ifrs-full:RetrospectiveApplicationAndRetrospectiveRestatementAxis
1468 Currently stated [member] Member ifrs-full:RestatedMember
1469 Increase (decrease) due to changes in accounting policy [member] Member ifrs-full:FinancialEffectOfChangesInAccountingPolicyMember
1470 Adjusted balance at January 1 after the impact of retroactive applications [member] Member umc:AdjustedBalanceAtJanuary1AfterTheImpactOfRetroactiveApplicationsMember
1471 Changes in deferred tax assets and liabilities [Line Items] LineItems umc:ChangesInDeferredTaxAssetsAndLiabilitiesLineItems
1472 Beginning Balance Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilityAsset
1473 Amounts recognized in profit or loss during the period Concept (Monetary) For Period ifrs-full:DeferredTaxExpenseIncomeRecognisedInProfitOrLoss
1474 Amounts recognized in other comprehensive income Concept (Monetary) For Period ifrs-full:IncomeTaxRelatingToComponentsOfOtherComprehensiveIncome
1475 Amounts recognized in equity Concept (Monetary) For Period ifrs-full:DeferredTaxRelatingToItemsChargedOrCreditedDirectlyToEquity
1476 Exchange adjustments Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughNetExchangeDifferencesDeferredTaxLiabilityAsset
1477 Ending Balance Concept (Monetary) As Of Credit ifrs-full:DeferredTaxLiabilityAsset
1478 1098 - Disclosure - Contents of Significant Accounts - Unused Tax Loss Carry-forward for Which No Deferred Income Tax Assets have been Recognized (Detail) Network

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*

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1479 Disclosure of temporary difference, unused tax losses and unused tax credits [table] Table

*

*

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1480 Maturity [axis] Axis ifrs-full:MaturityAxis
1481 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
1482 1-5 years [member] Member ifrs-full:LaterThanOneYearAndNotLaterThanFiveYearsMember
1483 6-10 years [member] Member ifrs-full:LaterThanFiveYearsAndNotLaterThanTenYearsMember
1484 more than 10 years [member] Member ifrs-full:LaterThanTenYearsMember
1485 Disclosure of temporary difference, unused tax losses and unused tax credits [line items] LineItems ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsLineItems
1486 Unused tax loss carry-forward for which no deferred income tax assets have been recognized Concept (Monetary) As Of ifrs-full:UnusedTaxLossesForWhichNoDeferredTaxAssetRecognised
1487 1099 - Disclosure - Contents of Significant Accounts - Income Tax - Additional Information (Detail) Network

*

*

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1488 Implied Table Table

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1489 Disclosure of temporary difference, unused tax losses and unused tax credits [abstract] Abstract ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsAbstract
1490 Deductible temporary differences for which no deferred income tax assets have been recognized Concept (Monetary) As Of ifrs-full:DeductibleTemporaryDifferencesForWhichNoDeferredTaxAssetIsRecognised
1491 Taxable temporary differences of unrecognized deferred tax liabilities associated with investments in subsidiaries Concept (Monetary) As Of ifrs-full:TemporaryDifferencesAssociatedWithInvestmentsInSubsidiariesBranchesAndAssociatesAndInterestsInJointVentures
1492 Corporate income tax rate Concept (Percent) For Period ifrs-full:ApplicableTaxRate
1493 Undistributed earnings tax Concept (Percent) For Period umc:UndistributedEarningsTaxPercentage
1494 1100 - Disclosure - Contents of Significant Accounts - Earnings Per Share (Detail) Network

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*

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1495 Implied Table Table

*

*

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1497 Earnings per share-basic Abstract ifrs-full:BasicEarningsPerShareAbstract
1498 Net income attributable to the parent company Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToOwnersOfParent
1499 Weighted-average number of ordinary shares for basic earnings per share (thousand shares) Concept (Shares) For Period ifrs-full:WeightedAverageShares
1500 Earnings per share-basic (NTD) Concept (Share) For Period ifrs-full:BasicEarningsLossPerShare
1501 Earnings per share-diluted Abstract ifrs-full:DilutedEarningsPerShareAbstract
1502 Net income attributable to the parent company Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToOwnersOfParent
1503 Effect of dilution Abstract umc:DilutiveEffectOnNetIncomeAbstract
1504 Unsecured convertible bonds Concept (Monetary) For Period Credit umc:UnsecuredConvertibleBonds
1505 Income attributable to stockholders of the parent Concept (Monetary) For Period Credit ifrs-full:ProfitLossAttributableToOrdinaryEquityHoldersOfParentEntityIncludingDilutiveEffects
1506 Weighted-average number of common stocks for basic earnings per share (thousand shares) Concept (Shares) For Period ifrs-full:WeightedAverageShares
1507 Effect of dilution Abstract umc:DilutiveEffectOnSharesAbstract
1508 Employees' compensation Concept (Shares) For Period umc:DilutiveEffectOfEmployeeCompensationOnNumberOfOrdinaryShares
1509 Unsecured convertible bonds Concept (Shares) For Period ifrs-full:DilutiveEffectOfConvertibleInstrumentsOnNumberOfOrdinaryShares
1510 Weighted-average number of common stocks after dilution (thousand shares) Concept (Shares) For Period ifrs-full:AdjustedWeightedAverageShares
1511 Earnings per share-diluted (NTD) Concept (Share) For Period ifrs-full:DilutedEarningsLossPerShare
1512 1101 - Disclosure - Contents of Significant Accounts - Reconciliation of Liabilities Arising from Financing Activities (Detail) Network

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*

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1513 Disclosure of reconciliation of liabilities arising from financing activities [table] Table

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*

 ifrs-full:DisclosureOfReconciliationOfLiabilitiesArisingFromFinancingActivitiesTable
1514 Liabilities arising from financing activities [axis] Axis ifrs-full:LiabilitiesArisingFromFinancingActivitiesAxis
1515 Liabilities arising from financing activities [member] Member ifrs-full:LiabilitiesArisingFromFinancingActivitiesMember
1516 Short-term borrowings [member] Member ifrs-full:ShorttermBorrowingsMember
1517 Long-term loans [member] Member umc:LongTermLoansMember
1518 Bonds payable [member] Member umc:BondsPayableMember
1519 Guarantee deposits [member] Member umc:GuaranteeDepositsMember
1520 Other financial liabilities - noncurrent [member] Member umc:OtherFinancialLiabilitiesNoncurrentMember
1521 Disclosure of reconciliation of liabilities arising from financing activities [line items] LineItems ifrs-full:DisclosureOfReconciliationOfLiabilitiesArisingFromFinancingActivitiesLineItems
1522 Beginning balance Concept (Monetary) As Of Credit ifrs-full:LiabilitiesArisingFromFinancingActivities
1523 Cash Flows Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughFinancingCashFlowsLiabilitiesArisingFromFinancingActivities
1524 Non-cash changes,Foreign exchange Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughEffectOfChangesInForeignExchangeRatesLiabilitiesArisingFromFinancingActivities
1525 Non-cash changes,Other Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughOtherChangesLiabilitiesArisingFromFinancingActivities
1526 Ending Balance Concept (Monetary) As Of Credit ifrs-full:LiabilitiesArisingFromFinancingActivities
1527 1102 - Disclosure - Contents of Significant Accounts - Summary of Derecognized Assets and Liabilities (Detail) Network

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*

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1528 Derecognized Assets And Liabilities [table] Table

*

*

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1529 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
1530 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
1531 UNISTARS CORP. [member] Member umc:UnistarsCorpMember
1532 Derecognized Assets And Liabilities [Line Items] LineItems umc:DerecognizedAssetsAndLiabilitiesLineItems
1533 Assets Abstract ifrs-full:AssetsAbstract
1534 Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
1535 Notes and accounts receivable Concept (Monetary) As Of Debit umc:NotesAndAccountsReceivable
1536 Inventories Concept (Monetary) As Of Debit ifrs-full:Inventories
1537 Property, plant and equipment Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
1538 Others Concept (Monetary) As Of Debit ifrs-full:OtherNoncurrentAssets
1539 Total assets Concept (Monetary) As Of Debit ifrs-full:Assets
1540 Liabilities Abstract ifrs-full:LiabilitiesAbstract
1541 Short-term loans Concept (Monetary) As Of Credit ifrs-full:ShorttermBorrowings
1542 Payables Concept (Monetary) As Of Credit ifrs-full:OtherCurrentPayables
1543 Current portion of long-term liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentPortionOfLongtermBorrowings
1544 Long-term loans Concept (Monetary) As Of Credit ifrs-full:NoncurrentPortionOfNoncurrentLoansReceived
1545 Others Concept (Monetary) As Of Credit ifrs-full:OtherNoncurrentLiabilities
1546 Liabilities Concept (Monetary) As Of Credit ifrs-full:Liabilities
1547 Net assets of the subsidiary deconsolidated Concept (Monetary) As Of Debit ifrs-full:NetAssetsLiabilities
1548 1103 - Disclosure - Contents of Significant Accounts - Summary of Consideration Received and Loss Recognized (Detail) Network

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*

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1549 Consideration Received And Loss Recognized From Transaction [table] Table

*

*

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1550 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
1551 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
1552 UNISTARS CORP. [member] Member umc:UnistarsCorpMember
1553 Consideration Received And Loss Recognized From Transaction [Line Items] LineItems umc:ConsiderationReceivedAndLossRecognizedFromTransactionLineItems
1554 Cash received Concept (Monetary) As Of Debit umc:CashReceived
1555 Less: Net assets of the subsidiary deconsolidated Concept (Monetary) As Of Debit ifrs-full:NetAssetsLiabilities
1556 Add: Non-controllinginterests Concept (Monetary) As Of Credit ifrs-full:NoncontrollingInterests
1557 Less: Goodwill Concept (Monetary) As Of Debit ifrs-full:Goodwill
1558 Loss on disposal of subsidiary Concept (Monetary) For Period Credit ifrs-full:GainsLossesRecognisedWhenControlInSubsidiaryIsLost
1559 1104 - Disclosure - Contents of Significant Accounts - Summary of Net Cash Outflow Arising from Deconsolidation of the Subsidiary (Detail) Network

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*

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1560 Implied Table Table

*

*

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1561 Net Cash Outflow Arising From Deconsolidation Of Subsidiary [Abstract] Abstract umc:NetCashOutflowArisingFromDeconsolidationOfSubsidiaryAbstract
1562 Cash received Concept (Monetary) As Of Debit umc:CashReceived
1563 Net cash of subsidiary derecognized Concept (Monetary) For Period Debit ifrs-full:CashAndCashEquivalentsInSubsidiaryOrBusinessesAcquiredOrDisposed2013
1564 Net cash outflow from deconsolidation Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromLosingControlOfSubsidiariesOrOtherBusinessesClassifiedAsInvestingActivities
1565 1105 - Disclosure - Significant Related Party Transactions - Significant Intercompany Transactions Between Consolidated Entities (Detail) Network

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*

 http://www.umc.com/taxonomy/role/DisclosureSignificantRelatedPartyTransactionsSignificantIntercompanyTransactionsBetweenConsolidatedEntities
1566 Disclosure of transactions between related parties [table] Table

*

*

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1567 Legal Entity [Axis] Axis dei:LegalEntityAxis
1568 Entity [Domain] Member dei:EntityDomain
1569 WAVETEK MICROELECTRONICS CORPORATION (WAVETEK) [member] Member umc:WavetekMicroelectronicsCorporationMember
1570 HEJIAN TECHNOLOGY (SUZHOU) CO., LTD. (HJ) [member] Member umc:HejianTechnologySuzhouCoLtdMember
1571 UNITED SEMICONDUCTOR (XIAMEN) CO., LTD. (USCXM) [member] Member umc:UnitedSemiconductorXiamenCoLtdMember
1572 Counterparties [axis] Axis ifrs-full:CounterpartiesAxis
1573 Counterparties [member] Member ifrs-full:CounterpartiesMember
1574 UMC GROUP (USA) [member] Member umc:UMCGroupUSAMember
1575 UMC GROUP JAPAN [member] Member umc:UMCGroupJapanMember
1576 UNITED SEMICONDUCTOR (XIAMEN) CO., LTD. (USCXM) [member] Member umc:UnitedSemiconductorXiamenCoLtdMember
1577 WAVETEK MICROELECTRONICS CORPORATION (WAVETEK) [member] Member umc:WavetekMicroelectronicsCorporationMember
1578 Disclosure of transactions between related parties [line items] LineItems ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesLineItems
1579 Sales Concept (Monetary) For Period Credit ifrs-full:RevenueFromSaleOfGoodsRelatedPartyTransactions
1580 Accounts receivable Concept (Monetary) As Of Debit ifrs-full:AmountsReceivableRelatedPartyTransactions
1581 Royalty Concept (Monetary) For Period Credit ifrs-full:RevenueFromRoyalties
1582 Explanation of terms and conditions of outstanding balances for related party transaction Concept (Text/String) For Period ifrs-full:ExplanationOfTermsAndConditionsOfOutstandingBalancesForRelatedPartyTransaction
1583 Loan receivable Concept (Monetary) As Of Debit umc:LoansReceivableRelatedPartyTransactions
1584 Amount of downstream transaction Concept (Monetary) For Period ifrs-full:TransfersUnderLicenseAgreementsFromEntityRelatedPartyTransactions
1585 1106 - Disclosure - Significant Related Party Transactions - Significant Transactions between Company and Other Related Parties (Detail) Network

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*

 http://www.umc.com/taxonomy/role/DisclosureSignificantRelatedPartyTransactionsSignificantTransactionsBetweenCompanyAndOtherRelatedParties
1586 Disclosure of transactions between related parties [table] Table

*

*

 ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesTable
1587 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
1588 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
1589 Associates [member] Member ifrs-full:AssociatesMember
1590 Joint ventures [member] Member ifrs-full:JointVenturesWhereEntityIsVenturerMember
1591 Other related parties [member] Member ifrs-full:OtherRelatedPartiesMember
1592 All other related parties [member] Member umc:AllOtherRelatedPartiesMember
1593 Carrying amount, accumulated depreciation, amortization and impairment and gross carrying amount [Axis] Axis ifrs-full:CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis
1594 Carrying amount [member] Member ifrs-full:CarryingAmountMember
1595 Cost [member] Member ifrs-full:GrossCarryingAmountMember
1596 Allowance for sales returns and discounts [member] Member umc:AllowanceForSalesReturnsAndDiscountsMember
1597 Disclosure of transactions between related parties [line items] LineItems ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesLineItems
1598 Operating revenues Concept (Monetary) For Period Credit ifrs-full:RevenueFromSaleOfGoodsRelatedPartyTransactions
1599 Accounts receivable-related parties, net Concept (Monetary) As Of Debit ifrs-full:TradeAndOtherCurrentReceivablesDueFromRelatedParties
1600 Refund liability, current Concept (Monetary) As Of Credit umc:RefundLiabilityCurrent
1601 Acquisition of intangible assets Concept (Monetary) For Period Credit ifrs-full:PurchaseOfIntangibleAssetsClassifiedAsInvestingActivities
1602 Acquisition of investments accounted for under the equity method, Purchase price Concept (Monetary) As Of Debit ifrs-full:InvestmentAccountedForUsingEquityMethod
1603 Acquisition of investments accounted for under the equity method, Trading Volume Concept (Shares) For Period umc:AcquisitionOfShares
1604 Disposal of subsidiaries, Proceeds Concept (Monetary) As Of Debit umc:CashReceived
1605 Disposal of subsidiary, Disposal gain (loss) Concept (Monetary) For Period Credit ifrs-full:GainsLossesRecognisedWhenControlInSubsidiaryIsLost
1606 Disposal of subsidiary, Trading Volume Concept (Shares) For Period umc:DisposalOfSubsidiaryTradingShares
1607 Disposal of available-for-sale financial assets, noncurrent, Proceeds Concept (Monetary) For Period Debit ifrs-full:ProceedsFromDisposalOrMaturityOfAvailableforsaleFinancialAssets
1608 Disposal of available-for-sale financial assets, noncurrent, Disposal gain (loss) Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnDisposalsOfInvestments
1609 Disposal of available-for-sale financial assets, noncurrent, Trading Volume Concept (Shares) For Period umc:DisposalOnAvailableforsaleFinancialAssetsTradingShares
1610 Mask expenditure Concept (Monetary) For Period Debit umc:MaskExpenditureRelatedPartyTransactions
1611 Other payables of mask expenditure Concept (Monetary) For Period Debit umc:OtherPayablesOfMaskExpenditureRelatedPartyTransactions
1612 1107 - Disclosure - Significant Related Party Transactions - Additional Information (Detail) Network

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*

 http://www.umc.com/taxonomy/role/DisclosureSignificantRelatedPartyTransactionsAdditionalInformation
1613 Disclosure of transactions between related parties [table] Table

*

*

 ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesTable
1614 Geographical areas [axis] Axis ifrs-full:GeographicalAreasAxis
1615 Geographical areas [member] Member ifrs-full:GeographicalAreasMember
1616 Domestic [member] Member ifrs-full:CountryOfDomicileMember
1617 Overseas [member] Member ifrs-full:ForeignCountriesMember
1618 Range [axis] Axis ifrs-full:RangeAxis
1619 Ranges [member] Member ifrs-full:RangesMember
1620 Bottom of range [member] Member ifrs-full:BottomOfRangeMember
1621 Top of range [member] Member ifrs-full:TopOfRangeMember
1622 Disclosure of transactions between related parties [line items] LineItems ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesLineItems
1623 Collection periods for accounts receivables Concept (Text/String) For Period ifrs-full:ExplanationOfTermsAndConditionsOfOutstandingBalancesForRelatedPartyTransaction
1624 1108 - Disclosure - Significant Related Party Transactions - Key Management Personnel Compensation (Detail) Network

*

*

 http://www.umc.com/taxonomy/role/DisclosureSignificantRelatedPartyTransactionsKeyManagementPersonnelCompensation
1625 Implied Table Table

*

*

 implied:Table
1626 Disclosure of transactions between related parties [abstract] Abstract ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesAbstract
1627 Short-term employee benefits Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensationShorttermEmployeeBenefits
1628 Post-employment benefits Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensationPostemploymentBenefits
1629 Termination benefits Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensationTerminationBenefits
1630 Share-based payment Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensationSharebasedPayment
1631 Others Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensationOtherLongtermBenefits
1632 Total Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensation
1633 1109 - Disclosure - Assets Pledged as Collateral - Summary of Assets Pledged as Collateral (Detail) Network

*

*

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1634 Disclosure Assets Pledged As Collateral [Table] Table

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*

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1635 Classes of assets [axis] Axis ifrs-full:ClassesOfAssetsAxis
1636 Assets [member] Member ifrs-full:ClassesOfAssetsMember
1637 Refundable deposits time deposit and bank deposit [member] Member umc:RefundableDepositsTimeDepositAndBankDepositMember
1638 Refundable deposits time deposit [member] Member umc:RefundableDepositsTimeDepositMember
1639 Buildings [member] Member ifrs-full:BuildingsMember
1640 Machinery and equipment [member] Member umc:MachineryAndEquipment1Member
1641 Other non current assets [member] Member umc:OtherNoncurrentAssets1Member
1642 Counterparties [axis] Axis ifrs-full:CounterpartiesAxis
1643 Counterparties [member] Member ifrs-full:CounterpartiesMember
1644 Customs [member] Member umc:CustomsMember
1645 Science park administration [member] Member umc:ScienceParkAdministrationMember
1646 Liquefied natural gas business division, CPC corporation, Taiwan [member] Member umc:LiquefiedNaturalGasBusinessDivisionCPCCorporationTaiwanMember
1647 Bank of China [member] Member umc:BankOfChinaMember
1648 Taiwan cooperative bank and secured syndicated loans from China development bank and 6 others [member] Member umc:TaiwanCooperativeBankAndSecuredSyndicatedLoansFromChinaDevelopmentBankAnd6OthersMember
1649 Taiwan cooperative bank mega international commercial bank and secured syndicated loans from China development bank and 6 others [member] Member umc:TaiwanCooperativeBankMegaInternationalCommercialBankAndSecuredSyndicatedLoansFromChinaDevelopmentBankAnd6OthersMember
1650 Secured syndicated loans from China development bank and 6 others [member] Member umc:SecuredSyndicatedLoansFromChinaDevelopmentBankAnd6OthersMember
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1652 Classes of acquired receivables [member] Member ifrs-full:ClassesOfAcquiredReceivablesMember
1653 Dormitory lease [member] Member umc:DormitoryLeaseMember
1654 Research project performance guarantees [member] Member umc:ResearchProjectPerformanceGuaranteesMember
1655 Assets Pledged As Collateral [Line Items] LineItems umc:AssetsPledgedAsCollateralLineItems
1656 Assets pledged as collateral Concept (Monetary) As Of Debit ifrs-full:AssetsHeldAsCollateralPermittedToBeSoldOrRepledgedAtFairValue
1657 Purpose of pledge Concept (Text/String) For Period umc:PurposeOfPledge
1658 1110 - Disclosure - Significant Contingencies and Unrecognized Contract Commitments - Additional Information (Detail) Network

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*

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1659 Disclosure of contingent liabilities [table] Table

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1662 Machinery and equipment [member] Member umc:MachineryAndEquipment1Member
1663 Subsidiaries [axis] Axis ifrs-full:SignificantInvestmentsInSubsidiariesAxis
1664 Entity's total for subsidiaries [member] Member ifrs-full:EntitysTotalForSubsidiariesMember
1665 UNITED SEMICONDUCTOR (XIAMEN) CO., LTD. (USCXM) [member] Member umc:UnitedSemiconductorXiamenCoLtdMember
1666 Classes of intangible assets other than goodwill [axis] Axis ifrs-full:ClassesOfIntangibleAssetsOtherThanGoodwillAxis
1667 Intangible assets other than goodwill [member] Member ifrs-full:IntangibleAssetsOtherThanGoodwillMember
1668 Technology licenses [Member] Member umc:TechnologyLicensesMember
1669 Non-adjusting events after reporting period [axis] Axis ifrs-full:NonadjustingEventsAfterReportingPeriodAxis
1670 Non-adjusting events after reporting period [member] Member ifrs-full:NonadjustingEventsMember
1671 International Business Machines Corporation [Member] Member umc:InternationalBusinessMachinesCorporationMember
1672 Disclosure of contingent liabilities [line items] LineItems ifrs-full:DisclosureOfContingentLiabilitiesLineItems
1673 Amounts available under unused letters of credit for importing machinery and equipment Concept (Monetary) As Of Credit ifrs-full:UndrawnBorrowingFacilities
1674 Litigations and customs tax guarantee Concept (Monetary) As Of Credit umc:LitigationsAndCustomsTaxGuaranteeAmount
1675 Patent license agreements and development contracts of intellectual property, contract amount Concept (Monetary) As Of Credit ifrs-full:ContractualCommitmentsForAcquisitionOfIntangibleAssets
1676 Royalties and development fees not yet recognized Concept (Monetary) As Of Credit umc:RoyaltiesAndDevelopmentFeesNotYetRecognized
1677 Construction contracts, amount Concept (Monetary) As Of Credit ifrs-full:ContractualCommitmentsForAcquisitionOfPropertyPlantAndEquipment
1678 Construction contracts not yet recognized Concept (Monetary) As Of Debit umc:ConstructionContractsNotYetRecognized
1679 Amount of investment in subsidiaries Concept (Monetary) As Of Debit ifrs-full:InvestmentsInSubsidiariesJointVenturesAndAssociates
1680 Ownership interest in subsidiary Concept (Percent) For Period ifrs-full:ProportionOfOwnershipInterestInSubsidiary
1681 Financial liability recognized in other noncurrent liabilities for the purchase from the other investors of their investments Concept (Monetary) As Of Credit ifrs-full:FinancialLiabilitiesRecognisedAsOfAcquisitionDate
1682 Claim amount Concept (Monetary) For Period Credit umc:CompensationClaimAmount
1683 Claim interest rate Concept (Percent) For Period umc:ClaimsInterestRate
1684 Litigation settlement amount Concept (Monetary) For Period Debit umc:LitigationSettlementAmount1
1685 1111 - Disclosure - Significant Contingencies and Unrecognized Contract Commitments - Future Minimum Lease Payments under Renewable Operating Leases (Detail) Network

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*

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1686 Disclosure of finance lease and operating lease by lessee [table] Table

*

*

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1687 Maturity [axis] Axis ifrs-full:MaturityAxis
1688 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
1689 Not later than one year [member] Member ifrs-full:NotLaterThanOneYearMember
1690 Later than one year and not later than two years [member] Member ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMember
1691 Later than two years and not later than three years [member] Member ifrs-full:LaterThanTwoYearsAndNotLaterThanThreeYearsMember
1692 Later than three years and not later than four years [member] Member ifrs-full:LaterThanThreeYearsAndNotLaterThanFourYearsMember
1693 Later than four years and not later than five years [member] Member ifrs-full:LaterThanFourYearsAndNotLaterThanFiveYearsMember
1694 Later than five years [member] Member ifrs-full:LaterThanFiveYearsMember
1695 Disclosure of finance lease and operating lease by lessee [line items] LineItems ifrs-full:DisclosureOfFinanceLeaseAndOperatingLeaseByLesseeLineItems
1696 Future minimum lease payments Concept (Monetary) As Of Credit ifrs-full:MinimumLeasePaymentsPayableUnderNoncancellableOperatingLease
1697 1112 - Disclosure - Financial Risk and Fair Value Disclosures - Categories of Financial Instruments (Detail) Network

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*

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1698 Implied Table Table

*

*

 implied:Table
1699 Disclosure of detailed information about financial instruments [abstract] Abstract ifrs-full:DisclosureOfFinancialInstrumentsAbstract
1700 Financial assets at fair value through profit or loss Concept (Monetary) As Of Debit umc:FinancialAssetsAtFairValueThroughProfitOrLossExcludingDerivatives
1701 Financial assets at fair value through other comprehensive income Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssetsAtFairValueThroughOtherComprehensiveIncome
1702 Available-for-sale financial assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssetsAvailableforsale
1703 Financial assets measured at cost Concept (Monetary) As Of Debit ifrs-full:NoncurrentFinancialAssetsAtAmortisedCost
1704 Financial assets measured at amortized cost Abstract umc:FinancialAssetsMeasuredAtAmortizedCostAbstract
1705 Cash and cash equivalents (excludes cash on hand) Concept (Monetary) As Of Debit umc:CashAndCashEquivalentsExcludingCashOnHand
1706 Receivables Concept (Monetary) As Of Debit ifrs-full:TradeAndOtherReceivables
1707 Refundable deposits Concept (Monetary) As Of Debit ifrs-full:LongtermDeposits
1708 Other financial assets Concept (Monetary) As Of Debit ifrs-full:OtherFinancialAssets
1709 Financial assets measured at amortized cost Concept (Monetary) As Of Debit ifrs-full:CurrentFinancialAssetsAtAmortisedCost
1710 Financial assets at fair value through profit or loss Concept (Monetary) As Of Debit ifrs-full:DerivativeFinancialAssets
1711 Total Concept (Monetary) As Of Debit ifrs-full:FinancialAssets
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1713 Payables Concept (Monetary) As Of Credit ifrs-full:TradeAndOtherPayables
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1719 1113 - Disclosure - Financial Risk and Fair Value Disclosures - Additional Information (Detail) Network

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1720 Disclosure of nature and extent of risks arising from financial instruments [table] Table

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1745 Disclosure Of Maturity Analysis For Non-derivative And Derivative Financial Liabilities [Table] Table

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1750 Later than four years and not later than five years [member] Member ifrs-full:LaterThanFourYearsAndNotLaterThanFiveYearsMember
1751 Later than five years [member] Member ifrs-full:LaterThanFiveYearsMember
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1760 1115 - Disclosure - Financial Risk and Fair Value Disclosures - Details of Forward Exchange Contracts (Detail) Network

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1761 Disclosure of detailed information about financial instruments [table] Table

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1770 Disclosure of detailed information about financial instruments [table] Table

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1781 1117 - Disclosure - Financial Risk and Fair Value Disclosures - Reconciliations for Fair Value Measurement in Level 3 Fair Value Hierarchy (Detail) Network

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1782 Disclosure of fair value measurement of assets [table] Table

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1796 Preferred stocks [member] Member ifrs-full:PreferenceSharesMember
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1809 1118 - Disclosure - Financial Risk and Fair Value Disclosures - Summary of Significant Unobservable Inputs of Fair Value Measurement in Level 3 Fair Value Hierarchy (Detail) Network

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1810 Disclosure of significant unobservable inputs used in fair value measurement of equity [table] Table

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1829 1119 - Disclosure - Financial Risk and Fair Value Disclosures - Summary of Significant Unobservable Inputs of Fair Value Measurement in Level 3 Fair Value Hierarchy (Parenthetical) (Detail) Network

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1830 Disclosure of significant unobservable inputs used in fair value measurement of equity [table] Table

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1850 1120 - Disclosure - Financial Risk and Fair Value Disclosures - Assets and Liabilities Not Recorded at Fair Value on a Recurring Basis But for Which Fair Value is Disclosed (Detail) Network

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1851 Disclosure of fair value measurement of liabilities [table] Table

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1860 Disclosure of fair value measurement of liabilities [line items] LineItems ifrs-full:DisclosureOfFairValueMeasurementOfLiabilitiesLineItems
1861 Bonds payables (current portion included) Concept (Monetary) As Of Credit ifrs-full:BondsIssued
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1863 1121 - Disclosure - Operating Segment Information - Reportable Segment Information (Detail) Network

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1864 Disclosure of Operating Segments [Table] Table

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1884 1122 - Disclosure - Operating Segment Information - Geographic Information, Non-current Assets (Detail) Network

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1885 Disclosure of Geographical Areas [Table] Table

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1896 1123 - Disclosure - Operating Segment Information - Individual Customers Accounting for at least 10% of Operating Revenues (Detail) Network

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1897 Disclosure of Major Customers [Table] Table

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1910 1124 - Disclosure - Capital Management - Debt to Capital Ratios (Detail) Network

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1911 Implied Table Table

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1914 Less: Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
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1916 Total equity Concept (Monetary) As Of Credit ifrs-full:Equity
1917 Total capital Concept (Monetary) As Of Credit umc:TotalCapital
1918 Debt to capital ratios Concept (Percent) As Of umc:DebtToCapitalRatios

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