LITHIUM AMERICAS CORP. (SEC Filing Page | XBRL Cloud Viewer | XBRL Instance)

Line Label Object Class Period Type Balance Report ElementName
1 100000 - Document - Document and Entity Information Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DocumentDocumentAndEntityInformation
2 Implied Table Table

*

*

 implied:Table
3 Document And Entity Information [Abstract] Abstract lac: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 Current Reporting Status Concept (Yes/No) For Period dei:EntityCurrentReportingStatus
14 Entity Emerging Growth Company Concept (Yes/No) For Period dei:EntityEmergingGrowthCompany
15 Entity Ex Transition Period Concept (Yes/No) For Period dei:EntityExTransitionPeriod
16 Entity Common Stock, Shares Outstanding Concept (Shares) As Of dei:EntityCommonStockSharesOutstanding
17 100010 - Statement - Consolidated Statements of Financial Position Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/StatementConsolidatedStatementsOfFinancialPosition
18 Implied Table Table

*

*

 implied:Table
19 Statement Of Financial Position [Abstract] Abstract ifrs-full:StatementOfFinancialPositionAbstract
20 CURRENT ASSETS Abstract ifrs-full:CurrentAssetsAbstract
21 Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
22 Restricted cash Concept (Monetary) As Of Debit ifrs-full:CurrentRestrictedCashAndCashEquivalents
23 Receivables, prepaids and deposits Concept (Monetary) As Of Debit ifrs-full:TradeAndOtherCurrentReceivables
24 Deferred financing costs Concept (Monetary) As Of Debit lac:DeferredFinancingCostCurrent
25 Organoclay inventories Concept (Monetary) As Of Debit ifrs-full:Inventories
26 Total current assets Concept (Monetary) As Of Debit ifrs-full:CurrentAssets
27 NON-CURRENT ASSETS Abstract ifrs-full:NoncurrentAssetsAbstract
28 Restricted cash Concept (Monetary) As Of Debit ifrs-full:NoncurrentRestrictedCashAndCashEquivalents
29 Loans to Joint Venture Concept (Monetary) As Of Debit ifrs-full:NoncurrentLoansAndReceivables
30 Investment in Joint Venture Concept (Monetary) As Of Debit ifrs-full:InvestmentsInSubsidiariesJointVenturesAndAssociates
31 Property, plant and equipment Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
32 Exploration and evaluation assets Concept (Monetary) As Of Debit ifrs-full:IntangibleExplorationAndEvaluationAssets
33 Total non-current assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentAssets
34 TOTAL ASSETS Concept (Monetary) As Of Debit ifrs-full:Assets
35 CURRENT LIABILITIES Abstract ifrs-full:CurrentLiabilitiesAbstract
36 Accounts payable and accrued liabilities Concept (Monetary) As Of Credit ifrs-full:TradeAndOtherCurrentPayables
37 Current portion of long-term borrowings Concept (Monetary) As Of Credit ifrs-full:CurrentPortionOfLongtermBorrowings
38 Total current liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentLiabilities
39 LONG-TERM LIABILITIES Abstract ifrs-full:NoncurrentLiabilitiesAbstract
40 Long-term borrowings Concept (Monetary) As Of Credit ifrs-full:LongtermBorrowings
41 Decommissioning provision Concept (Monetary) As Of Credit ifrs-full:LongtermProvisionForDecommissioningRestorationAndRehabilitationCosts
42 Total long-term liabilities Concept (Monetary) As Of Credit ifrs-full:NoncurrentLiabilities
43 TOTAL LIABILITIES Concept (Monetary) As Of Credit ifrs-full:Liabilities
44 SHAREHOLDERS’ EQUITY Abstract ifrs-full:EquityAbstract
45 Share capital Concept (Monetary) As Of Credit ifrs-full:IssuedCapital
46 Contributed surplus Concept (Monetary) As Of Credit ifrs-full:AdditionalPaidinCapital
47 Accumulated other comprehensive loss Concept (Monetary) As Of Credit ifrs-full:AccumulatedOtherComprehensiveIncome
48 Deficit Concept (Monetary) As Of Credit ifrs-full:RetainedEarnings
49 TOTAL SHAREHOLDERS’ EQUITY Concept (Monetary) As Of Credit ifrs-full:Equity
50 TOTAL LIABILITIES AND SHAREHOLDERS EQUITY Concept (Monetary) As Of Credit ifrs-full:EquityAndLiabilities
51 100020 - Statement - Consolidated Statements of Comprehensive Loss (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/StatementConsolidatedStatementsOfComprehensiveLossDetails
52 Implied Table Table

*

*

 implied:Table
53 Income Statement [Abstract] Abstract ifrs-full:IncomeStatementAbstract
54 ORGANOCLAY SALES Concept (Monetary) For Period Credit ifrs-full:Revenue
55 COST OF SALES Abstract lac:CostOfSaleAbstract
56 Production costs Concept (Monetary) For Period Debit lac:ProductionCost
57 Depreciation Concept (Monetary) For Period Debit lac:CostOfSalesDepreciation
58 Total cost of sales Concept (Monetary) For Period Debit ifrs-full:CostOfSales
59 GROSS LOSS Concept (Monetary) For Period Credit ifrs-full:GrossProfit
60 EXPENSES Abstract lac:ExpenseAbstract
61 Exploration expenditures Concept (Monetary) For Period Debit ifrs-full:ExpenseArisingFromExplorationForAndEvaluationOfMineralResources
62 Organoclay research and development Concept (Monetary) For Period Debit ifrs-full:ResearchAndDevelopmentExpense
63 General and administrative Concept (Monetary) For Period Debit ifrs-full:GeneralAndAdministrativeExpense
64 Stock-based compensation Concept (Monetary) For Period Debit ifrs-full:ExpenseFromSharebasedPaymentTransactionsWithEmployees
65 Share of loss in Joint Venture Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
66 Gain on increase of interest in Joint Venture Concept (Monetary) For Period Credit lac:GainLossOnIncreaseOfInterestInJointVenture
67 Impairment of Organoclay property, plant and equipment Concept (Monetary) For Period ifrs-full:ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipment
68 Transaction costs Concept (Monetary) For Period Debit lac:TransactionCosts
69 Total expenses Concept (Monetary) For Period Debit ifrs-full:OperatingExpenseExcludingCostOfSales
70 OTHER ITEMS Abstract lac:OtherIncomeExpenseAbstract
71 Foreign exchange gain/(loss) Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnExchangeDifferencesOnTranslationRecognisedInProfitOrLoss
72 Other income Concept (Monetary) For Period Credit lac:MiscellaneousOtherIncome
73 Total other items Concept (Monetary) For Period Credit lac:OtherIncomeExpense
74 NET LOSS Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
75 OTHER COMPREHENSIVE LOSS ITEMS THAT MAY BE RECLASSIFIED SUBSEQUENTLY TO NET LOSS Abstract ifrs-full:ComponentsOfOtherComprehensiveIncomeThatWillBeReclassifiedToProfitOrLossNetOfTaxAbstract
76 Unrealized (loss)/gain on translation to reporting currency Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncomeNetOfTaxExchangeDifferencesOnTranslation
77 TOTAL COMPREHENSIVE LOSS Concept (Monetary) For Period Credit ifrs-full:ComprehensiveIncome
78 LOSS PER SHARE - BASIC AND DILUTED Concept (Share) For Period ifrs-full:BasicAndDilutedEarningsLossPerShare
79 WEIGHTED AVERAGE NUMBER OF COMMON SHARES OUTSTANDING- BASIC AND DILUTED Concept (Shares) For Period ifrs-full:AdjustedWeightedAverageShares
80 100030 - Statement - Consolidated Statements of Changes in Equity Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/StatementConsolidatedStatementsOfChangesInEquity
81 Statement Of Changes In Equity [Table] Table

*

*

 ifrs-full:StatementOfChangesInEquityTable
82 Components of equity [axis] Axis ifrs-full:ComponentsOfEquityAxis
83 Equity [member] Member ifrs-full:EquityMember
84 Share Capital Member ifrs-full:IssuedCapitalMember
85 Contributed Surplus Member ifrs-full:AdditionalPaidinCapitalMember
86 Accumulated Other Comprehensive Loss Member ifrs-full:AccumulatedOtherComprehensiveIncomeMember
87 Deficit Member ifrs-full:RetainedEarningsMember
88 Statement Of Changes In Equity [Line Items] LineItems ifrs-full:StatementOfChangesInEquityLineItems
89 Beginning balance Concept (Monetary) As Of Credit ifrs-full:Equity
90 Beginning balance, Shares Concept (Shares) As Of ifrs-full:NumberOfSharesOutstanding
91 Shares issued on exercise of stock options Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughExerciseOfOptions
92 Shares issued on exercise of stock options, shares Concept (Shares) For Period lac:IncreaseDecreaseInNumberOfSharesIssuedOnExerciseOfStockOptions
93 Shares issued on exercise of warrants Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughExerciseOfWarrantsEquity
94 Shares issued on exercise of warrants, shares Concept (Shares) For Period lac:IncreaseDecreaseInNumberOfSharesIssuedOnExerciseOfWarrants
95 Shares issued on conversion of RSUs, DSUs and exercise of options Concept (Monetary) For Period Credit lac:IncreaseDecreaseThroughConversionOfOtherEquityInstruments
96 Shares issued on conversion of RSUs, DSUs and exercise of options, shares Concept (Shares) For Period lac:IncreaseDecreaseInNumberOfSharesIssuedOnConversionOfOtherEquityInstruments
97 DSUs and RSUs issued in lieu of salaries and directors’ fees Concept (Monetary) For Period Credit lac:IncreaseDecreaseThroughDeferredShareUnitsAndRestrictedSharesIssuedInLieuOfSalariesAndDirectorsFees
98 Shares issued for equity financing Concept (Monetary) For Period Credit ifrs-full:IssueOfEquity
99 Shares issued for equity financing, shares Concept (Shares) For Period lac:IncreaseDecreaseInNumberOfSharesIssuedForEquityFinancing
100 Share issuance costs Concept (Monetary) For Period Debit ifrs-full:ShareIssueRelatedCost
101 Stock-based compensation Concept (Monetary) For Period Credit ifrs-full:IncreaseDecreaseThroughSharebasedPaymentTransactions
102 Net loss Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
103 Other comprehensive income (loss) Concept (Monetary) For Period Credit ifrs-full:OtherComprehensiveIncome
104 Ending balance Concept (Monetary) As Of Credit ifrs-full:Equity
105 Ending balance, Shares Concept (Shares) As Of ifrs-full:NumberOfSharesOutstanding
106 100040 - Statement - Consolidated Statements of Changes in Equity (Parenthetical) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/StatementConsolidatedStatementsOfChangesInEquityParenthetical
107 Implied Table Table

*

*

 implied:Table
108 Statement Of Changes In Equity [Abstract] Abstract ifrs-full:StatementOfChangesInEquityAbstract
109 Share consolidation, number of outstanding common shares for each new common share Concept (Shares) As Of lac:ShareConsolidationConversionRatio
110 100050 - Statement - Consolidated Statements of Cash Flows (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/StatementConsolidatedStatementsOfCashFlowsDetails
111 Implied Table Table

*

*

 implied:Table
112 Statement Of Cash Flows [Abstract] Abstract ifrs-full:StatementOfCashFlowsAbstract
113 OPERATING ACTIVITIES Abstract ifrs-full:CashFlowsFromUsedInOperatingActivitiesAbstract
114 Net loss Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
115 Items not affecting cash: Abstract ifrs-full:AdjustmentsForReconcileProfitLossAbstract
116 Stock-based compensation Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForSharebasedPayments
117 Depreciation Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDepreciationExpense
118 Foreign exchange (gain)/loss Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForUnrealisedForeignExchangeLossesGains
119 Share of loss in Joint Venture Concept (Monetary) For Period Debit lac:AdjustmentsForShareOfLossInJointVenture
120 Inventories write down Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLossInventories
121 Gain on increase of interest in Joint Venture (Note 5) Concept (Monetary) For Period Credit lac:GainLossOnIncreaseOfInterestInJointVenture
122 Impairment of Organoclay property, plant and equipment Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForImpairmentLossReversalOfImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipment
123 Other expenses Concept (Monetary) For Period Debit lac:AdjustmentsForOtherIncome
124 Changes in non-cash working capital items: Abstract lac:AdjustmentsForChangesInNonCashWorkingCapitalItemsAbstract
125 Increase in receivables, prepaids and deposits Concept (Monetary) For Period Debit lac:AdjustmentsForIncreaseDecreaseInReceivablesPrepaidsAndDeposits
126 Decrease/(increase) in inventories Concept (Monetary) For Period Debit ifrs-full:AdjustmentsForDecreaseIncreaseInInventories
127 Increase in accounts payable and accrued liabilities Concept (Monetary) For Period Debit lac:AdjustmentsForIncreaseDecreaseInAccountsPayableAndAccruedLiabilities
128 Net cash used in operating activities Concept (Monetary) For Period ifrs-full:CashFlowsFromUsedInOperatingActivities
129 INVESTING ACTIVITIES Abstract ifrs-full:CashFlowsFromUsedInInvestingActivitiesAbstract
130 Loans to Joint Venture (Note 5) Concept (Monetary) For Period Credit ifrs-full:CashAdvancesAndLoansMadeToRelatedParties
131 Repayment of loans and investment in Joint Venture (Note 5) Concept (Monetary) For Period Credit lac:RepaymentOfLoansAndInvestmentInJointVenture
132 Contribution to Joint Venture (Note 5) Concept (Monetary) For Period Credit lac:ContributionToJointVenture
133 Additions to exploration and evaluation assets Concept (Monetary) For Period Credit ifrs-full:PurchaseOfExplorationAndEvaluationAssets
134 Release of restricted cash Concept (Monetary) For Period Debit lac:CashFlowsFromRestrictedCash
135 Additions to property, plant and equipment Concept (Monetary) For Period Credit ifrs-full:PurchaseOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities
136 Net cash used in investing activities Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromUsedInInvestingActivities
137 FINANCING ACTIVITIES Abstract ifrs-full:CashFlowsFromUsedInFinancingActivitiesAbstract
138 Proceeds from stock option exercises Concept (Monetary) For Period Debit ifrs-full:ProceedsFromExerciseOfOptions
139 Proceeds from warrant exercises Concept (Monetary) For Period Debit lac:ProceedsFromExerciseOfWarrants
140 Drawdowns from the credit facility (Note 8) Concept (Monetary) For Period Debit lac:DrawdownsFromTheCreditFacility
141 Debt financing costs paid Concept (Monetary) For Period Credit ifrs-full:PaymentsForDebtIssueCosts
142 Net proceeds from equity financing (Note 9) Concept (Monetary) For Period Debit ifrs-full:ProceedsFromIssuingOtherEquityInstruments
143 Finance lease repayments Concept (Monetary) For Period Credit ifrs-full:PaymentsOfFinanceLeaseLiabilitiesClassifiedAsFinancingActivities
144 Repayment of long-term borrowings Concept (Monetary) For Period Credit ifrs-full:RepaymentsOfBorrowingsClassifiedAsFinancingActivities
145 Net cash provided by financing activities Concept (Monetary) For Period Debit ifrs-full:CashFlowsFromUsedInFinancingActivities
146 EFFECT OF FOREIGN EXCHANGE ON CASH Concept (Monetary) For Period Debit ifrs-full:EffectOfExchangeRateChangesOnCashAndCashEquivalents
147 CHANGE IN CASH AND CASH EQUIVALENTS Concept (Monetary) For Period Debit ifrs-full:IncreaseDecreaseInCashAndCashEquivalents
148 CASH AND CASH EQUIVALENTS - BEGINNING OF THE YEAR Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
149 CASH AND CASH EQUIVALENTS - END OF THE YEAR Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
150 100060 - Disclosure - Nature of Operations Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureNatureOfOperations
151 Implied Table Table

*

*

 implied:Table
152 Nature Of Operations [Abstract] Abstract lac:NatureOfOperationsAbstract
153 Nature of Operations Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfGeneralInformationAboutFinancialStatementsExplanatory
154 100070 - Disclosure - Basis of Preparation and Presentation Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureBasisOfPreparationAndPresentation
155 Implied Table Table

*

*

 implied:Table
156 Basis Of Preparation And Presentation [Abstract] Abstract lac:BasisOfPreparationAndPresentationAbstract
157 Basis of Preparation and Presentation Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfBasisOfPreparationOfFinancialStatementsExplanatory
158 100080 - Disclosure - Significant Accounting Policies Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSignificantAccountingPolicies
159 Implied Table Table

*

*

 implied:Table
160 Disclosure Of Significant Accounting Policies [Abstract] Abstract lac:DisclosureOfSignificantAccountingPoliciesAbstract
161 Significant Accounting Policies Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfSummaryOfSignificantAccountingPoliciesExplanatory
162 100090 - Disclosure - Cash and Cash Equivalents Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureCashAndCashEquivalents
163 Implied Table Table

*

*

 implied:Table
164 Cash And Cash Equivalents [Abstract] Abstract ifrs-full:CashAndCashEquivalentsAbstract
165 Cash and Cash Equivalents Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfCashAndCashEquivalentsExplanatory
166 100100 - Disclosure - Joint Venture Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureJointVenture
167 Implied Table Table

*

*

 implied:Table
168 Disclosure Of Joint Ventures [Abstract] Abstract ifrs-full:DisclosureOfJointVenturesAbstract
169 Joint Venture Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfJointVenturesExplanatory
170 100110 - Disclosure - Property Plant and Equipment Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosurePropertyPlantAndEquipment
171 Implied Table Table

*

*

 implied:Table
172 Disclosure Of Property Plant And Equipment [Abstract] Abstract ifrs-full:DisclosureOfPropertyPlantAndEquipmentAbstract
173 Property Plant and Equipment Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfPropertyPlantAndEquipmentExplanatory
174 100120 - Disclosure - Exploration and Evaluation Assets Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureExplorationAndEvaluationAssets
175 Implied Table Table

*

*

 implied:Table
176 Exploration And Evaluation Assets [Abstract] Abstract lac:ExplorationAndEvaluationAssetsAbstract
177 Exploration and Evaluation Assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfExplorationAndEvaluationAssetsExplanatory
178 100130 - Disclosure - Long Term Borrowings Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureLongTermBorrowings
179 Implied Table Table

*

*

 implied:Table
180 Borrowings [Abstract] Abstract ifrs-full:BorrowingsAbstract
181 Long -Term Borrowings Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfBorrowingsExplanatory
182 100140 - Disclosure - Issued Capital, Equity Compensation and Warrants Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIssuedCapitalEquityCompensationAndWarrants
183 Implied Table Table

*

*

 implied:Table
184 Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Abstract] Abstract ifrs-full:DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementAbstract
185 Issued Capital, Equity Compensation and Warrants Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfIssuedCapitalExplanatory
186 100150 - Disclosure - Related Party Transactions Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureRelatedPartyTransactions
187 Implied Table Table

*

*

 implied:Table
188 Related Party Transactions [Abstract] Abstract ifrs-full:RelatedPartyTransactionsAbstract
189 Related Party Transactions Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfRelatedPartyExplanatory
190 100160 - Disclosure - General and Administrative Expenses Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureGeneralAndAdministrativeExpenses
191 Implied Table Table

*

*

 implied:Table
192 Disclosure Of General And Administrative Expenses [Abstract] Abstract lac:DisclosureOfGeneralAndAdministrativeExpensesAbstract
193 General and Administrative Expenses Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfGeneralAndAdministrativeExpenseExplanatory
194 100170 - Disclosure - Commitments and Contingencies Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureCommitmentsAndContingencies
195 Implied Table Table

*

*

 implied:Table
196 Disclosure Of Commitments And Contingencies [Abstract] Abstract lac:DisclosureOfCommitmentsAndContingenciesAbstract
197 Commitments and Contingencies Concept (Text Block (HTML)) For Period lac:DisclosureOfCommitmentsAndContingenciesExplanatory
198 100180 - Disclosure - Exploration Expenditures Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureExplorationExpenditures
199 Implied Table Table

*

*

 implied:Table
200 Disclosure Of Exploration Expenditures [Abstract] Abstract lac:DisclosureOfExplorationExpendituresAbstract
201 Exploration Expenditures Concept (Text Block (HTML)) For Period lac:DisclosureOfExplorationExpendituresExplanatory
202 100190 - Disclosure - Segmented Information Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSegmentedInformation
203 Implied Table Table

*

*

 implied:Table
204 Disclosure Of Operating Segments [Abstract] Abstract ifrs-full:DisclosureOfOperatingSegmentsAbstract
205 Segmented Information Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfEntitysReportableSegmentsExplanatory
206 100200 - Disclosure - Supplemental Disclosure with Respect to Cash Flows Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSupplementalDisclosureWithRespectToCashFlows
207 Implied Table Table

*

*

 implied:Table
208 Supplemental Information With Respect To Cash Flows [Abstract] Abstract lac:SupplementalInformationWithRespectToCashFlowsAbstract
209 Supplemental Disclosure with Respect to Cash Flows Concept (Text Block (HTML)) For Period lac:DisclosureOfSupplementalInformationWithRespectToCashFlowsExplanatory
210 100210 - Disclosure - Income Taxes Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIncomeTaxes
211 Implied Table Table

*

*

 implied:Table
212 Major Components Of Tax Expense Income [Abstract] Abstract ifrs-full:MajorComponentsOfTaxExpenseIncomeAbstract
213 Income Taxes Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfIncomeTaxExplanatory
214 100220 - Disclosure - Financial Instruments Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureFinancialInstruments
215 Implied Table Table

*

*

 implied:Table
216 Disclosure Of Financial Instruments [Abstract] Abstract ifrs-full:DisclosureOfFinancialInstrumentsAbstract
217 Financial Instruments Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfFinancialInstrumentsExplanatory
218 100230 - Disclosure - Capital Disclosures Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureCapitalDisclosures
219 Implied Table Table

*

*

 implied:Table
220 Disclosure Of Capital Disclosures [Abstract] Abstract lac:DisclosureOfCapitalDisclosuresAbstract
221 Capital Disclosures Concept (Text Block (HTML)) For Period lac:DisclosureOfCapitalDisclosuresExplanatory
222 100240 - Disclosure - Impairment of Non-current Assets Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureImpairmentOfNonCurrentAssets
223 Implied Table Table

*

*

 implied:Table
224 Impairment Of Non Current Assets [Abstract] Abstract lac:ImpairmentOfNonCurrentAssetsAbstract
225 Impairment of Non-current Assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfImpairmentOfAssetsExplanatory
226 100250 - Disclosure - Subsequent Events Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSubsequentEvents
227 Implied Table Table

*

*

 implied:Table
228 Disclosure Of Nonadjusting Events After Reporting Period [Abstract] Abstract ifrs-full:DisclosureOfNonadjustingEventsAfterReportingPeriodAbstract
229 Subsequent Events Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfNonadjustingEventsAfterReportingPeriodExplanatory
230 100260 - Disclosure - Significant Accounting Policies (Policies) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSignificantAccountingPoliciesPolicies
231 Implied Table Table

*

*

 implied:Table
232 Disclosure Of Significant Accounting Policies [Abstract] Abstract lac:DisclosureOfSignificantAccountingPoliciesAbstract
233 Critical Accounting Estimates and Judgments Concept (Text Block (HTML)) For Period lac:DescriptionOfAccountingPolicyForCriticalAccountingEstimatesAndJudgementsExplanatory
234 Principles of Consolidation Concept (Text Block (HTML)) For Period lac:DescriptionOfAccountingPolicyForPrinciplesOfConsolidationExplanatory
235 Investments in Joint Arrangements Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForInvestmentsInJointVentures
236 Foreign Currency Translation Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForForeignCurrencyTranslationExplanatory
237 Cash and Cash Equivalents Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyToDetermineComponentsOfCashAndCashEquivalents
238 Exploration and Evaluation Assets Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForExplorationAndEvaluationExpenditures
239 Property, Plant and Equipment Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForPropertyPlantAndEquipmentExplanatory
240 Impairment of Property, Plant and Equipment Concept (Text Block (HTML)) For Period lac:DescriptionOfAccountingPolicyForImpairmentOfPropertyPlantAndEquipmentExplanatory
241 Leased Assets Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForLeasesExplanatory
242 Inventories Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForMeasuringInventories
243 Financial Instruments Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForFinancialInstrumentsExplanatory
244 Borrowing Costs Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForBorrowingCostsExplanatory
245 Provisions Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForProvisionsExplanatory
246 Income Taxes Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForIncomeTaxExplanatory
247 Share Capital Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForIssuedCapitalExplanatory
248 Revenue Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForRecognitionOfRevenue
249 Earnings/(Loss) per Share Concept (Text Block (HTML)) For Period ifrs-full:DescriptionOfAccountingPolicyForEarningsPerShareExplanatory
250 Stock-Based Compensation Concept (Text Block (HTML)) For Period lac:DescriptionOfAccountingPolicyForStockBasedCompensationExplanatory
251 Organoclay Product Development Concept (Text Block (HTML)) For Period lac:DescriptionOfAccountingPolicyForOrganoclayProductDevelopmentExplanatory
252 Recent Accounting Pronouncements Concept (Text Block (HTML)) For Period lac:DescriptionOfAccountingPolicyForRecentAccountingPronouncementsExplanatory
253 100270 - Disclosure - Cash and Cash Equivalents - (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureCashAndCashEquivalentsTables
254 Implied Table Table

*

*

 implied:Table
255 Cash And Cash Equivalents [Abstract] Abstract ifrs-full:CashAndCashEquivalentsAbstract
256 Summary of Cash and Cash Equivalents Concept (Text Block (HTML)) For Period lac:DisclosureOfDetailedInformationAboutCashAndCashEquivalentsExplanatory
257 100280 - Disclosure - Joint Venture (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureJointVentureTables
258 Disclosure Of Joint Ventures [Table] Table

*

*

 ifrs-full:DisclosureOfJointVenturesTable
259 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
260 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
261 Minera Exar S.A. Member lac:MineraExarMember
262 Exar Capital B V Member lac:ExarCapitalBVMember
263 Disclosure Of Joint Ventures [Line Items] LineItems ifrs-full:DisclosureOfJointVenturesLineItems
264 Disclosure of Change in Investments in Joint Ventures Concept (Text Block (HTML)) For Period lac:DisclosureOfChangeInInvestmentsInJointVenturesExplanatory
265 Disclosure of Financial Statements Information of Joint Ventures Concept (Text Block (HTML)) For Period lac:DisclosureOfFinancialInformationOfJointVenturesExplanatory
266 Reconciliation of Summarized Financial Information to Carrying Value Concept (Text Block (HTML)) For Period lac:DisclosureOfReconciliationOfSummarizedFinancialInformationToCarryingValueExplanatory
267 Summary of Loans to Joint Venture Concept (Text Block (HTML)) For Period lac:DisclosureOfLoansToJointVenturesExplanatory
268 100290 - Disclosure - Property Plant and Equipment (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosurePropertyPlantAndEquipmentTables
269 Implied Table Table

*

*

 implied:Table
270 Disclosure Of Property Plant And Equipment [Abstract] Abstract ifrs-full:DisclosureOfPropertyPlantAndEquipmentAbstract
271 Summary of Property Plant and Equipment Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutPropertyPlantAndEquipmentExplanatory
272 100300 - Disclosure - Exploration and Evaluation Assets (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureExplorationAndEvaluationAssetsTables
273 Implied Table Table

*

*

 implied:Table
274 Exploration And Evaluation Assets [Abstract] Abstract lac:ExplorationAndEvaluationAssetsAbstract
275 Schedule of Exploration and Evaluation Assets Concept (Text Block (HTML)) For Period lac:DisclosureOfDetailedInformationAboutExplorationAndEvaluationAssetsExplanatory
276 100310 - Disclosure - Long Term Borrowings (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureLongTermBorrowingsTables
277 Implied Table Table

*

*

 implied:Table
278 Borrowings [Abstract] Abstract ifrs-full:BorrowingsAbstract
279 Schedule of Long-Term Borrowings Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsExplanatory
280 100320 - Disclosure - Issued Capital, Equity Compensation and Warrants (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIssuedCapitalEquityCompensationAndWarrantsTables
281 Implied Table Table

*

*

 implied:Table
282 Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Abstract] Abstract ifrs-full:DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementAbstract
283 Summary of Changes to Number of Restricted Shares Concept (Text Block (HTML)) For Period lac:DisclosureOfChangesToRestrictedSharesExplanatory
284 Summary of Changes to Number of Deferred Share Units Concept (Text Block (HTML)) For Period lac:DisclosureOfChangesToDeferredShareUnitsExplanatory
285 Summary of Fair Value of Stock Options Granted by Using Black-Scholes Option Pricing Model Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfIndirectMeasurementOfFairValueOfGoodsOrServicesReceivedShareOptionsGrantedDuringPeriodExplanatory
286 Summary of Stock Options Outstanding and Exercisable Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfRangeOfExercisePricesOfOutstandingShareOptionsExplanatory
287 Summary of Changes to Stock Options Outstanding Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfNumberAndWeightedAverageExercisePricesOfShareOptionsExplanatory
288 Summary of Fair Value of Performance Awards Granted by Using Monte Carlo Simulation Model Concept (Text Block (HTML)) For Period lac:DisclosureOfFairValueOfPerformanceAwardsGrantedByUsingMonteCarloSimulationModelExplanatory
289 Summary of Changes to Number of RS-Ps Concept (Text Block (HTML)) For Period lac:DisclosureOfChangesToRestrictedPerformanceSharesExplanatory
290 Summary of Changes in Number of Share Purchase Warrants Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfNumberAndWeightedAverageExercisePricesOfOtherEquityInstrumentsExplanatory
291 100330 - Disclosure - Related Party Transactions (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureRelatedPartyTransactionsTables
292 Implied Table Table

*

*

 implied:Table
293 Related Party Transactions [Abstract] Abstract ifrs-full:RelatedPartyTransactionsAbstract
294 Summary of Compensation of Key Management Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfAmountsIncurredByEntityForProvisionOfKeyManagementPersonnelServicesProvidedBySeparateManagementEntitiesExplanatory
295 100340 - Disclosure - General and Administrative Expenses (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureGeneralAndAdministrativeExpensesTables
296 Implied Table Table

*

*

 implied:Table
297 Disclosure Of General And Administrative Expenses [Abstract] Abstract lac:DisclosureOfGeneralAndAdministrativeExpensesAbstract
298 Summary of Company's General and Administrative Expenses Concept (Text Block (HTML)) For Period lac:DisclosureOfDetailedInformationAboutGeneralAndAdministrativeExpensesExplanatory
299 100350 - Disclosure - Commitments and Contingencies (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureCommitmentsAndContingenciesTables
300 Implied Table Table

*

*

 implied:Table
301 Disclosure Of Commitments And Contingencies [Abstract] Abstract lac:DisclosureOfCommitmentsAndContingenciesAbstract
302 Schedule of Other Commitments Concept (Text Block (HTML)) For Period lac:DisclosureOfOtherCommitmentExplanatory
303 100360 - Disclosure - Exploration Expenditures (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureExplorationExpendituresTables
304 Implied Table Table

*

*

 implied:Table
305 Disclosure Of Exploration Expenditures [Abstract] Abstract lac:DisclosureOfExplorationExpendituresAbstract
306 Summary of Company's Exploration Expenditures Concept (Text Block (HTML)) For Period lac:DisclosureOfDetailedInformationAboutExplorationExpendituresExplanatory
307 100370 - Disclosure - Segmented Information (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSegmentedInformationTables
308 Implied Table Table

*

*

 implied:Table
309 Disclosure Of Operating Segments [Abstract] Abstract ifrs-full:DisclosureOfOperatingSegmentsAbstract
310 Summary of Reportable Segments Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfOperatingSegmentsExplanatory
311 Schedule of Non-current Assets and Revenue by Geographical Segment Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfGeographicalAreasExplanatory
312 100380 - Disclosure - Supplemental Disclosure with Respect to Cash Flows (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSupplementalDisclosureWithRespectToCashFlowsTables
313 Implied Table Table

*

*

 implied:Table
314 Supplemental Information With Respect To Cash Flows [Abstract] Abstract lac:SupplementalInformationWithRespectToCashFlowsAbstract
315 Supplementary Disclosure of Company's Non Cash Transactions Concept (Text Block (HTML)) For Period lac:SupplementaryDisclosureOfCompanySNonCashTransactionExplanatory
316 100390 - Disclosure - Income Taxes (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIncomeTaxesTables
317 Implied Table Table

*

*

 implied:Table
318 Major Components Of Tax Expense Income [Abstract] Abstract ifrs-full:MajorComponentsOfTaxExpenseIncomeAbstract
319 Summary of Reconciliation of Income Taxes at Canadian Statutory Rates with Reported Taxes Concept (Text Block (HTML)) For Period lac:ReconciliationOfIncomeTaxesAtApplicableTaxRatesExplanatoryTextBlock
320 Summary of Significant Components of Company's Unrecognized Deferred Tax Assets Concept (Text Block (HTML)) For Period ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsExplanatory
321 100400 - Disclosure - Financial Instruments (Tables) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsTables
322 Implied Table Table

*

*

 implied:Table
323 Disclosure Of Financial Instruments [Abstract] Abstract ifrs-full:DisclosureOfFinancialInstrumentsAbstract
324 Summary of Maturities for Financial Liabilities on Undiscounted Basis Concept (Text Block (HTML)) For Period ifrs-full:MaturityAnalysisForNonderivativeFinancialLiabilities
325 100410 - Disclosure - Nature of Operations - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureNatureOfOperationsAdditionalInformationDetails
326 Implied Table Table

*

*

 implied:Table
327 Nature Of Operations [Abstract] Abstract lac:NatureOfOperationsAbstract
328 Name of reporting entity Concept (Text/String) For Period ifrs-full:NameOfReportingEntityOrOtherMeansOfIdentification
329 Number of significant projects Concept (Integer) For Period lac:NumberOfSignificantProjects
330 100420 - Disclosure - Basis of Preparation and Presentation - Additional Information (Detail) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureBasisOfPreparationAndPresentationAdditionalInformationDetail
331 Implied Table Table

*

*

 implied:Table
332 Basis Of Preparation And Presentation [Abstract] Abstract lac:BasisOfPreparationAndPresentationAbstract
333 Date of consolidated financial statements approved for issuance Concept (Date) For Period lac:DateOfConsolidatedFinancialStatementsApprovedForIssuance
334 Share consolidation, number of outstanding common shares for each new common share Concept (Shares) As Of lac:ShareConsolidationConversionRatio
335 100430 - Disclosure - Significant Accounting Policies - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSignificantAccountingPoliciesAdditionalInformationDetails
336 Significant Accounting Policies [Table] Table

*

*

 lac:SignificantAccountingPoliciesTable
337 Classes of property, plant and equipment [axis] Axis ifrs-full:ClassesOfPropertyPlantAndEquipmentAxis
338 Property, plant and equipment [member] Member ifrs-full:PropertyPlantAndEquipmentMember
339 Organoclay Plant Member lac:OrganoclayPlantMember
340 Buildings Member ifrs-full:BuildingsMember
341 Organoclay Plant Equipment Member lac:OrganoclayPlantEquipmentMember
342 Lithium Demo Plant Equipment Member lac:LithiumDemoPlantEquipmentMember
343 Office Equipment Member ifrs-full:OfficeEquipmentMember
344 Other Equipment Member ifrs-full:OtherPropertyPlantAndEquipmentMember
345 Range [axis] Axis ifrs-full:RangeAxis
346 Ranges [member] Member ifrs-full:RangesMember
347 Bottom of Range Member ifrs-full:BottomOfRangeMember
348 Top of Range Member ifrs-full:TopOfRangeMember
349 Non-adjusting events after reporting period [axis] Axis ifrs-full:NonadjustingEventsAfterReportingPeriodAxis
350 Non-adjusting events after reporting period [member] Member ifrs-full:NonadjustingEventsMember
351 Events after reporting period Member lac:EventsAfterReportingPeriodMember
352 Significant Accounting Policies [Line Items] LineItems lac:SignificantAccountingPoliciesLineItems
353 Non-cash impairment loss Concept (Monetary) For Period ifrs-full:ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipment
354 Property plant and equipment, estimated useful life Concept (xbrli:durationItemType) For Period lac:PropertyPlantAndEquipmentEstimatedUsefulLife
355 Property, plant and equipment, depreciation method Concept (Text/String) For Period ifrs-full:DepreciationMethodPropertyPlantAndEquipment
356 Property, plant and equipment, annual depreciation rate Concept (Percent) For Period lac:PropertyPlantAndEquipmentAnnualDepreciationRate
357 Lease assets Concept (Monetary) As Of Debit ifrs-full:RightofuseAssets
358 Lease liabilities Concept (Monetary) As Of Credit ifrs-full:LeaseLiabilities
359 100440 - Disclosure - Cash and Cash Equivalents - Summary of Cash and Cash Equivalents (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureCashAndCashEquivalentsSummaryOfCashAndCashEquivalentsDetails
360 Implied Table Table

*

*

 implied:Table
361 Cash And Cash Equivalents [Abstract] Abstract ifrs-full:CashAndCashEquivalentsAbstract
362 Cash Concept (Monetary) As Of Debit ifrs-full:Cash
363 Short-term bank deposits Concept (Monetary) As Of Debit ifrs-full:ShorttermDepositsClassifiedAsCashEquivalents
364 Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
365 100450 - Disclosure - Cash and Cash Equivalents - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureCashAndCashEquivalentsAdditionalInformationDetails
366 Disclosure Of Cash And Cash Equivalents [Table] Table

*

*

 lac:DisclosureOfCashAndCashEquivalentsTable
367 Range [axis] Axis ifrs-full:RangeAxis
368 Ranges [member] Member ifrs-full:RangesMember
369 Bottom of Range Member ifrs-full:BottomOfRangeMember
370 Top of Range Member ifrs-full:TopOfRangeMember
371 Currency Axis srt:CurrencyAxis
372 All Currencies Member currency:AllCurrenciesDomain
373 Canadian Dollar Member currency:CAD
374 US Dollar Member currency:USD
375 Disclosure Of Cash And Cash Equivalents [Line Items] LineItems lac:DisclosureOfCashAndCashEquivalentsLineItems
376 Cash Concept (Monetary) As Of Debit ifrs-full:Cash
377 Percentage of interest on cash Concept (Percent) As Of lac:PercentageOfInterestOnCash
378 Percentage of interest on short term bank deposits Concept (Percent) As Of lac:PercentageOfInterestOnShortTermBankDeposits
379 100460 - Disclosure - Joint Venture - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureJointVentureAdditionalInformationDetails
380 Disclosure Of Joint Ventures [Table] Table

*

*

 ifrs-full:DisclosureOfJointVenturesTable
381 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
382 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
383 Minera Exar S.A. Member lac:MineraExarMember
384 Exar Capital B V Member lac:ExarCapitalBVMember
385 Associates [axis] Axis ifrs-full:SignificantInvestmentsInAssociatesAxis
386 Entity's total for associates [member] Member ifrs-full:EntitysTotalForAssociatesMember
387 Ganfeng Member lac:GanfengInvestmentAgreementMember
388 Ownership Axis srt:OwnershipAxis
389 Ownership Member srt:OwnershipDomain
390 Minera Exar S.A. Member lac:MineraExarMember
391 Segments [axis] Axis ifrs-full:SegmentsAxis
392 Segments [member] Member ifrs-full:SegmentsMember
393 Cauchari-Olaroz Member lac:CauchariOlarozMember
394 Range [axis] Axis ifrs-full:RangeAxis
395 Ranges [member] Member ifrs-full:RangesMember
396 Bottom of Range Member ifrs-full:BottomOfRangeMember
397 Top of Range Member ifrs-full:TopOfRangeMember
398 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
399 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
400 Grupo Minero Los Boros Member lac:GrupoMineroLosBorosMember
401 Types of contracts [axis] Axis ifrs-full:TypesOfContractsAxis
402 Types of contracts [member] Member ifrs-full:TypesOfContractsMember
403 JEMSE Arrangement Member lac:JEMSEArrangementMember
404 Disclosure Of Joint Ventures [Line Items] LineItems ifrs-full:DisclosureOfJointVenturesLineItems
405 Percentage of right to purchase share of production Concept (Percent) For Period lac:PercentageOfRightToPurchaseShareOfProduction
406 Ownership interest in joint venture Concept (Percent) For Period ifrs-full:ProportionOfOwnershipInterestInJointVenture
407 Ownership interest held by non-controlling interest Concept (Percent) For Period ifrs-full:ProportionOfOwnershipInterestsHeldByNoncontrollingInterests
408 Borrowing facility Concept (Monetary) As Of Credit ifrs-full:UndrawnBorrowingFacilities
409 Repayments of outstanding indebtness Concept (Monetary) For Period Credit ifrs-full:RepaymentsOfCurrentBorrowings
410 Restricted cash Concept (Monetary) As Of Debit ifrs-full:CurrentRestrictedCashAndCashEquivalents
411 Investment repaid Concept (Monetary) For Period Debit ifrs-full:InflowsOfCashFromInvestingActivities
412 Accounts receivable Concept (Monetary) As Of Debit ifrs-full:ReceivablesDueFromJointVentures
413 Increase in ownership interest percentage Concept (Pure) For Period lac:IncreaseInProportionOfOwnershipInterestInJointVenture
414 Share of loss in Joint Venture Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
415 Loan to related party Concept (Monetary) For Period Debit lac:LoanToRelatedParty
416 Amount of difference between face value and fair value of non-interest-bearing loans Concept (Monetary) For Period Debit lac:AmountOfDifferenceBetweenFaceValueAndFairValueOfNonInterestBearingLoans
417 Number of communities Concept (Integer) For Period lac:NumberOfCommunities
418 Term of Project Concept (xbrli:durationItemType) For Period lac:TermOfProject
419 Annual royalty due Concept (Monetary) For Period Credit lac:AnnualRoyaltyDue
420 Royalty expiration description Concept (Text/String) For Period lac:RoyaltyExpirationDescription
421 Annual fees due in 2017 to 2021 Concept (Monetary) For Period Credit lac:AnnualFeesDueInTwentySeventeenToTwentyTwentyOne
422 Annual fees due in 2021 to 2055 Concept (Monetary) For Period Credit lac:AnnualFeesDueInTwentyTwentyOneToTwentyFiftyFive
423 Commitments related to contract for construction of ponds Concept (Monetary) As Of Credit ifrs-full:ContractualCapitalCommitments
424 Description of terms of option agreement Concept (Text/String) For Period lac:DescriptionOfTermsAndConditionsOfOptionsAgreement
425 Payment for purchase option Concept (Monetary) For Period Debit lac:PaymentForPurchaseOptionJointVenture
426 Total consideration on right to exercise purchase option Concept (Monetary) For Period Credit lac:TotalConsiderationOnRightToExercisePurchaseOption
427 Consideration payments in quarterly installments Concept (Monetary) For Period Credit lac:ConsiderationPaymentsInQuarterlyInstallments
428 Minimum production for the purchase option exercise Concept (num:weightItemType) For Period lac:MinimumLithiumProductionForPurchaseOptionExercise
429 Borrowings of joint venture Concept (Monetary) As Of Credit lac:BorrowingsFromJointVentures
430 Royalty payment upon the exercises the purchase option Concept (Monetary) For Period Credit lac:RoyaltyPaymentUponExercisesPurchaseOption
431 Royalty payment description Concept (Text/String) For Period lac:RoyaltyPaymentDescription
432 Net operating interest of exercises the purchase option Concept (Percent) For Period lac:NetOperatingInterestOfExercisesPurchaseOption
433 Net operation interest payable description Concept (Text/String) For Period lac:NetOperationInterestPayableDescription
434 One time payment in exchange of first 20 years of net profit interest Concept (Monetary) For Period Credit lac:OneTimePaymentInExchangeOfFirstTwentyYearsOfNetProfitInterest
435 One time payment in exchange of next 20 years of net profit interest Concept (Monetary) For Period Credit lac:OneTimePaymentInExchangeOfNextTwentyYearsOfNetProfitInterest
436 Rights granted to acquire equity interest in joint venture, percentage Concept (Percent) For Period lac:RightsGrantedToAcquireEquityInterestInJointVenturePercentage
437 Rights granted to acquire equity interest in joint venture, value Concept (Monetary) For Period Credit lac:RightsGrantedToAcquireEquityInterestInJointVentureValue
438 Percentage of pro rata share Concept (Percent) For Period lac:PercentageOfProRataShare
439 100470 - Disclosure - Joint Venture - Summary of Changes in Investments in Joint Ventures Initial Contribution (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureJointVentureSummaryOfChangesInInvestmentsInJointVenturesInitialContributionDetails
440 Disclosure Of Joint Ventures [Table] Table

*

*

 ifrs-full:DisclosureOfJointVenturesTable
441 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
442 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
443 Minera Exar S.A. Member lac:MineraExarMember
444 Exar Capital B V Member lac:ExarCapitalBVMember
445 Disclosure Of Joint Ventures [Line Items] LineItems ifrs-full:DisclosureOfJointVenturesLineItems
446 Investment in Joint Venture. Balance Concept (Monetary) As Of Debit ifrs-full:InvestmentsInJointVentures
447 Share of loss of Joint Venture Concept (Monetary) For Period Credit ifrs-full:ShareOfProfitLossOfJointVenturesAccountedForUsingEquityMethod
448 Translation adjustment Concept (Monetary) For Period Credit lac:InvestmentInJointVentureTranslationAdjustment
449 Contribution to Joint Venture Concept (Monetary) For Period Credit lac:CashAndNonCashContributionsToJointVenture
450 Return of the investment as part of the Transaction Concept (Monetary) For Period Credit lac:JointVentureInvestmentReturn
451 Increase in Company's share as part of the Transaction Concept (Monetary) For Period Credit lac:GainLossOnIncreaseOfInterestInJointVenture
452 Elimination of unrealized interest on loans to Joint Venture Concept (Monetary) For Period Credit lac:EliminationOfUnrealizedInterestOnLoansToJointVenture
453 Elimination of unrealized gain on intercompany transactions Concept (Monetary) For Period Credit lac:EliminationOfUnrealizedGainsOnIntercompanyTransactions
454 Investment in Joint Venture. Balance Concept (Monetary) As Of Debit ifrs-full:InvestmentsInJointVentures
455 100480 - Disclosure - Joint Venture - Summary of Financial Statements Information of Joint Ventures (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureJointVentureSummaryOfFinancialStatementsInformationOfJointVenturesDetails
456 Disclosure Of Joint Ventures [Table] Table

*

*

 ifrs-full:DisclosureOfJointVenturesTable
457 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
458 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
459 Minera Exar S.A. Member lac:MineraExarMember
460 Exar Capital B V Member lac:ExarCapitalBVMember
461 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
462 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
463 Minera Exar S.A. Member lac:MineraExarMember
464 Lithium Americas and Ganfeng Member lac:LithiumAmericasAndGanfengMember
465 Disclosure Of Joint Ventures [Line Items] LineItems ifrs-full:DisclosureOfJointVenturesLineItems
466 CURRENT ASSETS Abstract ifrs-full:CurrentAssetsAbstract
467 Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
468 Other current assets Concept (Monetary) As Of Debit ifrs-full:OtherCurrentAssets
469 Total current assets Concept (Monetary) As Of Debit ifrs-full:CurrentAssets
470 Non-current assets Concept (Monetary) As Of Debit ifrs-full:NoncurrentAssets
471 Current liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentLiabilities
472 Non-current liabilities Concept (Monetary) As Of Credit ifrs-full:NoncurrentLiabilities
473 TOTAL ASSETS Concept (Monetary) As Of Debit ifrs-full:Assets
474 Exploration expenditures Concept (Monetary) For Period Debit ifrs-full:ExpenseArisingFromExplorationForAndEvaluationOfMineralResources
475 Depreciation Concept (Monetary) For Period Debit ifrs-full:DepreciationExpense
476 Other expense Concept (Monetary) For Period Credit lac:OtherExpenseIncome
477 NET LOSS Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
478 Other current liabilities Concept (Monetary) As Of Credit ifrs-full:OtherCurrentLiabilities
479 Interest income on loans Concept (Monetary) For Period Credit ifrs-full:InterestIncomeOnLoansAndReceivables
480 General and administrative Concept (Monetary) For Period Debit ifrs-full:GeneralAndAdministrativeExpense
481 100500 - Disclosure - Joint Venture - Reconciliation of Summarized Financial Information to Carrying Value (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureJointVentureReconciliationOfSummarizedFinancialInformationToCarryingValueDetails
482 Disclosure Of Joint Ventures [Table] Table

*

*

 ifrs-full:DisclosureOfJointVenturesTable
483 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
484 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
485 Minera Exar S.A. Member lac:MineraExarMember
486 Exar Capital B V Member lac:ExarCapitalBVMember
487 Unconsolidated structured entities [axis] Axis ifrs-full:UnconsolidatedStructuredEntitiesAxis
488 Entity's total for unconsolidated structured entities [member] Member ifrs-full:EntitysTotalForUnconsolidatedStructuredEntitiesMember
489 50% of Return on Investment Member lac:FiftyPercentageOfReturnOnInvestmentMember
490 Disclosure Of Joint Ventures [Line Items] LineItems ifrs-full:DisclosureOfJointVenturesLineItems
491 Opening net assets Concept (Monetary) As Of Debit ifrs-full:Assets
492 Equity contribution Concept (Monetary) For Period Credit lac:EquityContribution
493 Return of the investment as part of the Transaction Concept (Monetary) For Period Credit lac:JointVentureInvestmentReturn
494 Net loss Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
495 Closing net assets, December 31, 2018 Concept (Monetary) As Of Debit ifrs-full:Assets
496 Company's share of net assets (62.5%) Concept (Monetary) For Period Debit lac:ShareOfNetAssetsOfJointVenture
497 Elimination of unrealized gain on intercompany transactions and other Concept (Monetary) For Period Credit lac:EliminationOfUnrealizedGainsOnIntercompanyTransactionsAndOther
498 Joint Venture expenditures incurred by the Company Concept (Monetary) For Period Debit lac:JointVentureExpenditures
499 Difference between the face value and the fair value of loans to Exar Capital B.V. Concept (Monetary) For Period Debit lac:AmountOfDifferenceBetweenFaceValueAndFairValueOfNonInterestBearingLoans
500 Carrying value Concept (Monetary) As Of Debit ifrs-full:InvestmentsInJointVentures
501 100510 - Disclosure - Joint Venture - Reconciliation of Summarized Financial Information to Carrying Value (Parenthetical) (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureJointVentureReconciliationOfSummarizedFinancialInformationToCarryingValueParentheticalDetails
502 Disclosure Of Joint Ventures [Table] Table

*

*

 ifrs-full:DisclosureOfJointVenturesTable
503 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
504 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
505 Minera Exar S.A. Member lac:MineraExarMember
506 Exar Capital B V Member lac:ExarCapitalBVMember
507 Disclosure Of Joint Ventures [Line Items] LineItems ifrs-full:DisclosureOfJointVenturesLineItems
508 Percentage of share of net assets Concept (Percent) For Period lac:PercentageOfShareOfNetAssets
509 Percentage of return of investment in joint venture Concept (Percent) For Period lac:PercentageOfReturnOfInvestmentInJointVenture
510 100520 - Disclosure - Joint Venture - Summary of Loans to Joint Venture (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureJointVentureSummaryOfLoansToJointVentureDetails
511 Disclosure Of Joint Ventures [Table] Table

*

*

 ifrs-full:DisclosureOfJointVenturesTable
512 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
513 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
514 LIBOR Member lac:LIBORMember
515 Disclosure Of Joint Ventures [Line Items] LineItems ifrs-full:DisclosureOfJointVenturesLineItems
516 Loans to Joint Venture Concept (Monetary) For Period Debit lac:LoansGrantedToJointVenture
517 Accrued interest Concept (Monetary) For Period Debit ifrs-full:InterestExpenseOnBorrowings
518 Loans to Joint Venture, at December 31, 2017 Concept (Monetary) As Of Debit ifrs-full:NoncurrentLoansAndReceivables
519 Repayment of principal and accrued interest as part of the Transaction Concept (Monetary) For Period Credit lac:RepaymentOfLoansAndInvestmentInJointVenture
520 Loans granted to Exar Capital B.V. Concept (Monetary) For Period Debit lac:LoanGrantedToRelatedParty
521 Difference between the face value and the fair value of loans to Exar Capital B.V. Concept (Monetary) For Period Debit lac:AmountOfDifferenceBetweenFaceValueAndFairValueOfNonInterestBearingLoans
522 100530 - Disclosure - Joint Venture - Summary of Loans to Joint Venture (Parenthetical) (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureJointVentureSummaryOfLoansToJointVentureParentheticalDetails
523 Disclosure Of Joint Ventures [Table] Table

*

*

 ifrs-full:DisclosureOfJointVenturesTable
524 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
525 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
526 Minera Exar S.A. Member lac:MineraExarMember
527 Types of interest rates [axis] Axis ifrs-full:TypesOfInterestRatesAxis
528 Interest rate types [member] Member ifrs-full:InterestRateTypesMember
529 LIBOR Member lac:LIBORMember
530 Disclosure Of Joint Ventures [Line Items] LineItems ifrs-full:DisclosureOfJointVenturesLineItems
531 Borrowings, interest rate basis Concept (Text/String) For Period ifrs-full:BorrowingsInterestRateBasis
532 Borrowings, adjustment to interest rate basis Concept (Percent) As Of ifrs-full:BorrowingsAdjustmentToInterestRateBasis
533 Maturity period of borrowings Concept (Text/String) For Period ifrs-full:BorrowingsMaturity
534 100540 - Disclosure - Property Plant and Equipment - Summary of Property Plant and Equipment (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosurePropertyPlantAndEquipmentSummaryOfPropertyPlantAndEquipmentDetails
535 Disclosure Of Property Plant And Equipment [Table] Table

*

*

 ifrs-full:DisclosureOfPropertyPlantAndEquipmentTable
536 Classes of property, plant and equipment [axis] Axis ifrs-full:ClassesOfPropertyPlantAndEquipmentAxis
537 Property, plant and equipment [member] Member ifrs-full:PropertyPlantAndEquipmentMember
538 Land Member ifrs-full:LandMember
539 Buildings Member ifrs-full:BuildingsMember
540 Equipment and Machinery Member ifrs-full:MachineryMember
541 Organoclay Plant Member lac:OrganoclayPlantMember
542 Other Member ifrs-full:OtherPropertyPlantAndEquipmentMember
543 Carrying amount, accumulated depreciation, amortisation and impairment and gross carrying amount [axis] Axis ifrs-full:CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis
544 Carrying amount [member] Member ifrs-full:CarryingAmountMember
545 Cost Member ifrs-full:GrossCarryingAmountMember
546 Accumulated Depreciation Member ifrs-full:AccumulatedDepreciationAndAmortisationMember
547 Disclosure Of Property Plant And Equipment [Line Items] LineItems ifrs-full:DisclosureOfPropertyPlantAndEquipmentLineItems
548 Net book value at beginning of the year Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
549 Depreciation for the year Concept (Monetary) For Period ifrs-full:DepreciationPropertyPlantAndEquipment
550 Additions Concept (Monetary) For Period Debit ifrs-full:AdditionsOtherThanThroughBusinessCombinationsPropertyPlantAndEquipment
551 Disposals Concept (Monetary) For Period Credit ifrs-full:DisposalsPropertyPlantAndEquipment
552 Write down/Impairment Concept (Monetary) For Period ifrs-full:WritedownsReversalsOfPropertyPlantAndEquipment
553 Net book value at ending of the year Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
554 100550 - Disclosure - Exploration and Evaluation Assets - Schedule of Exploration and Evaluation Assets (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureExplorationAndEvaluationAssetsScheduleOfExplorationAndEvaluationAssetsDetails
555 Disclosure Of Exploration And Evaluation Assets [Table] Table

*

*

 lac:DisclosureOfExplorationAndEvaluationAssetsTable
556 Classes of assets [axis] Axis ifrs-full:ClassesOfAssetsAxis
557 Assets [member] Member ifrs-full:ClassesOfAssetsMember
558 Exploration and Evaluation Assets Member ifrs-full:ExplorationAndEvaluationAssetsMember
559 Segments [axis] Axis ifrs-full:SegmentsAxis
560 Segments [member] Member ifrs-full:SegmentsMember
561 Thacker Pass Member lac:ThackerPassMember
562 Disclosure Of Exploration And Evaluation Assets [Line Items] LineItems lac:DisclosureOfExplorationAndEvaluationAssetsLineItems
563 Acquisition costs Abstract lac:AcquisitionCostsAbstract
564 Total exploration and evaluation assets, beginning balance Concept (Monetary) As Of Debit ifrs-full:AssetsArisingFromExplorationForAndEvaluationOfMineralResources
565 Additions Concept (Monetary) For Period Debit ifrs-full:AdditionsToNoncurrentAssets
566 Write offs Concept (Monetary) For Period ifrs-full:WritedownsReversalsOfPropertyPlantAndEquipment
567 Change in foreign exchange rate Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnExchangeDifferencesOnTranslationRecognisedInProfitOrLoss
568 Sale of 50% of net assets Concept (Monetary) For Period Credit lac:SaleOfNetAssets
569 Contribution to Joint Venture Concept (Monetary) For Period Credit lac:ContributionToJointVenturePropertyPlantAndEquipment
570 Total exploration and evaluation assets, ending balance Concept (Monetary) As Of Debit ifrs-full:AssetsArisingFromExplorationForAndEvaluationOfMineralResources
571 100560 - Disclosure - Exploration and Evaluation Assets - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureExplorationAndEvaluationAssetsAdditionalInformationDetails
572 Disclosure Of Exploration And Evaluation Assets [Table] Table

*

*

 lac:DisclosureOfExplorationAndEvaluationAssetsTable
573 Segments [axis] Axis ifrs-full:SegmentsAxis
574 Segments [member] Member ifrs-full:SegmentsMember
575 Thacker Pass Member lac:ThackerPassMember
576 Maturity [axis] Axis ifrs-full:MaturityAxis
577 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
578 Smelter Royalty Payment Due on November 15 Member lac:SmelterRoyaltyPaymentDueOnNovemberFifteenMember
579 2019 Member ifrs-full:NotLaterThanOneYearMember
580 2020 Member ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMember
581 2021 Member ifrs-full:LaterThanTwoYearsAndNotLaterThanThreeYearsMember
582 2022 Member ifrs-full:LaterThanThreeYearsAndNotLaterThanFourYearsMember
583 2023 Member ifrs-full:LaterThanFourYearsAndNotLaterThanFiveYearsMember
584 Disclosure Of Exploration And Evaluation Assets [Line Items] LineItems lac:DisclosureOfExplorationAndEvaluationAssetsLineItems
585 Advance net smelter return royalty payment Concept (Monetary) For Period Credit lac:ExplorationAndEvaluationOfAssetsAdvanceNetSmelterReturnRoyaltyPayments
586 Number of mining claims Concept (Decimal) As Of lac:NumberOfMiningClaims
587 Percentage of net smelter return royalty Concept (Percent) For Period lac:ExplorationAndEvaluationOfAssetsAdvancePercentageOnNetSmelterReturnRoyalty
588 Percentage of royalty revenue Concept (Percent) For Period lac:PercentageOfRoyaltyRevenue
589 Percentage of gross royalty revenue Concept (Percent) For Period lac:PercentageOfGrossRoyaltyRevenue
590 Cumulative payment Concept (Monetary) For Period Credit lac:ExplorationAndEvaluationOfAssetsRoyaltyCumulativePayment
591 Percentage royalty revenue, reduction Concept (Percent) For Period lac:PercentageOfEstimatedDecreaseInRoyaltyRevenue
592 Percentage of option to reduce royalty revenue Concept (Percent) For Period lac:PercentageOfRightToReductionInRoyaltyRevenue
593 100570 - Disclosure - Long-Term Borrowings - Schedule of Long-Term Borrowings (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureLongTermBorrowingsScheduleOfLongTermBorrowingsDetails
594 Disclosure Of Detailed Information About Borrowings [Table] Table

*

*

 ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsTable
595 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
596 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
597 Promissory Note Member lac:PromissoryNoteMember
598 Obligation Under Finance Leases Member lac:ObligationUnderFinanceLeasesMember
599 Accrued Interest Member lac:AccruedInterestMember
600 Credit Facility Member lac:CreditFacilityMember
601 Disclosure Of Detailed Information About Borrowings [Line Items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
602 Current portion of long-term borrowings Abstract ifrs-full:CurrentBorrowingsAndCurrentPortionOfNoncurrentBorrowingsAbstract
603 Current portion of long-term borrowings Concept (Monetary) As Of Credit ifrs-full:CurrentPortionOfLongtermBorrowings
604 Long-term borrowings Abstract lac:LongTermBorrowingsAbstract
605 Long-term borrowings Concept (Monetary) As Of Credit ifrs-full:LongtermBorrowings
606 Borrowings Concept (Monetary) As Of Credit ifrs-full:Borrowings
607 100580 - Disclosure - Long-Term Borrowings - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureLongTermBorrowingsAdditionalInformationDetails
608 Disclosure Of Detailed Information About Borrowings [Table] Table

*

*

 ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsTable
609 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
610 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
611 Credit Facility Member lac:CreditFacilityMember
612 Non-Recourse Loan Agreement Member lac:NonRecourseLoanAgreementMember
613 Maturity [axis] Axis ifrs-full:MaturityAxis
614 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
615 First Three Years Member lac:NotLaterThanThreeYearsMember
616 Year Four Member ifrs-full:LaterThanThreeYearsAndNotLaterThanFourYearsMember
617 Year Five Member ifrs-full:LaterThanFourYearsAndNotLaterThanFiveYearsMember
618 Year Six Member lac:LaterThanFiveYearsAndNotLaterThanSixYearsMember
619 Associates [axis] Axis ifrs-full:SignificantInvestmentsInAssociatesAxis
620 Entity's total for associates [member] Member ifrs-full:EntitysTotalForAssociatesMember
621 Ganfeng Member lac:GanfengInvestmentAgreementMember
622 Disclosure Of Detailed Information About Borrowings [Line Items] LineItems ifrs-full:DisclosureOfDetailedInformationAboutBorrowingsLineItems
623 Proceed from long-term borrowings Concept (Monetary) For Period Debit ifrs-full:ProceedsFromNoncurrentBorrowings
624 Finance costs Concept (Monetary) For Period Debit ifrs-full:FinanceCosts
625 Drawn borrowing facilities Concept (Monetary) For Period Debit lac:DrawdownsFromTheCreditFacility
626 Credit facility term Concept (xbrli:durationItemType) For Period lac:CreditFacilityTerm
627 Borrowings interest rate Concept (Percent) As Of ifrs-full:BorrowingsInterestRate
628 Percentage of right to purchase share of production Concept (Percent) For Period lac:PercentageOfRightToPurchaseShareOfProduction
629 Purchase price of property Concept (Monetary) For Period Credit lac:PurchasePriceOfPropertyPurchased
630 Payments for purchase of property Concept (Monetary) For Period Credit lac:PaymentsForPurchaseOfProperty
631 Remaining balance of transaction Concept (Monetary) As Of Credit lac:RemainingBalanceOfPurchaseTransaction
632 Promissory note, maturity term Concept (xbrli:durationItemType) For Period lac:PromissoryNoteMaturityTerm
633 Annual interest of promissory note for first five years Concept (Percent) For Period lac:AnnualInterestOfPromissoryNoteForFirstFiveYears
634 Borrowing facility Concept (Monetary) As Of Credit ifrs-full:UndrawnBorrowingFacilities
635 Borrowings, interest rate basis Concept (Text/String) For Period ifrs-full:BorrowingsInterestRateBasis
636 100590 - Disclosure - Issued Capital, Equity Compensation, and Warrants - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIssuedCapitalEquityCompensationAndWarrantsAdditionalInformationDetails
637 Disclosure Of Issued Capital Equity Compensation And Warrants [Table] Table

*

*

 lac:DisclosureOfIssuedCapitalEquityCompensationAndWarrantsTable
638 Associates [axis] Axis ifrs-full:SignificantInvestmentsInAssociatesAxis
639 Entity's total for associates [member] Member ifrs-full:EntitysTotalForAssociatesMember
640 Ganfeng Member lac:GanfengInvestmentAgreementMember
641 BCP Innovation Pte Ltd Member lac:BCPIMember
642 Ganfeng and Bangchak Investment Agreements Member lac:GanfengAndBangchakInvestmentAgreementsMember
643 Bangchak Member lac:BangchakInvestmentAgreementMember
644 Range [axis] Axis ifrs-full:RangeAxis
645 Ranges [member] Member ifrs-full:RangesMember
646 Bottom of Range Member ifrs-full:BottomOfRangeMember
647 Top of Range Member ifrs-full:TopOfRangeMember
648 Classes of liabilities [axis] Axis ifrs-full:ClassesOfLiabilitiesAxis
649 Liabilities [member] Member ifrs-full:LiabilitiesMember
650 Debt Issuance Costs Member lac:DebtIssuanceCostsMember
651 Accrued Liabilities Reduction Member lac:AccruedLiabilitiesReductionMember
652 Operating Expenses Member lac:OperatingExpensesMember
653 Defined benefit plans [axis] Axis ifrs-full:DefinedBenefitPlansAxis
654 Defined benefit plans [member] Member ifrs-full:DefinedBenefitPlansMember
655 Equity Incentive Plan Member lac:EquityIncentivePlanMember
656 Types of share-based payment arrangements [axis] Axis ifrs-full:TypesOfSharebasedPaymentArrangementsAxis
657 Share-based payment arrangements [member] Member ifrs-full:SharebasedPaymentArrangementsMember
658 Restricted Share Units Member lac:RestrictedShareUnitsMember
659 Deferred Share Units Member lac:DeferredShareUnitsMember
660 Cashless Exercise Provision Stock Option Plan Member lac:CashlessExerciseProvisionStockOptionPlanMember
661 Performance Share Units Member lac:PerformanceShareUnitsMember
662 Maturity [axis] Axis ifrs-full:MaturityAxis
663 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
664 2019 Member ifrs-full:NotLaterThanOneYearMember
665 2020 Member ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMember
666 2021 Member ifrs-full:LaterThanTwoYearsAndNotLaterThanThreeYearsMember
667 Balance Sheet Location Axis us-gaap:BalanceSheetLocationAxis
668 Balance Sheet Location Member us-gaap:BalanceSheetLocationDomain
669 Inventory Member lac:InventoryMember
670 Income Statement Location Axis us-gaap:IncomeStatementLocationAxis
671 Income Statement Location Member us-gaap:IncomeStatementLocationDomain
672 Operating Expense Member us-gaap:OperatingExpenseMember
673 Cost of Sales Member us-gaap:CostOfSalesMember
674 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
675 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
676 Directors, Officers and Employees Member ifrs-full:KeyManagementPersonnelOfEntityOrParentMember
677 Statement Scenario Axis us-gaap:StatementScenarioAxis
678 Scenario Unspecified Member us-gaap:ScenarioUnspecifiedDomain
679 2019 Member lac:TwoThousandNineteenMember
680 Disclosure Of Issued Capital Equity Compensation And Warrants [Line Items] LineItems lac:DisclosureOfIssuedCapitalEquityCompensationAndWarrantsLineItems
681 Number of shares issued Concept (Shares) As Of ifrs-full:NumberOfSharesIssued
682 Par value per share Concept (Share) As Of ifrs-full:ParValuePerShare
683 Gross proceeds from common share Concept (Monetary) For Period Debit ifrs-full:ProceedsFromIssuingShares
684 Credit facility Concept (Monetary) As Of Credit ifrs-full:Borrowings
685 Commitments related to contract for construction of ponds Concept (Monetary) As Of Credit ifrs-full:ContractualCapitalCommitments
686 Percentage of offtake entitlement Concept (Percent) For Period lac:PercentageOfOfftakeEntitlement
687 Off-take agreements term Concept (xbrli:durationItemType) For Period lac:OffTakeAgreementsTerm
688 Percentage of interest required in issued capital to nominate one individual. Concept (Percent) For Period lac:PercentageOfInterestRequiredInIssuedCapitalToNominateOneIndividual
689 Financing costs related to the equity portion Concept (Monetary) For Period Credit ifrs-full:PaymentsForShareIssueCosts
690 Deferred financing costs Concept (Monetary) As Of Debit lac:DeferredFinancingCostCurrent
691 Accounts payable and accrued liabilities Concept (Monetary) As Of Credit ifrs-full:TradeAndOtherCurrentPayables
692 Maximum percentage of outstanding common shares reserved for issuance Concept (Percent) For Period lac:MaximumPercentageOfOutstandingCommonSharesReservedForIssuance
693 Maximum term for stock option granted Concept (xbrli:durationItemType) For Period lac:StockOptionGrantedMaximumTerm
694 Number of shares granted Concept (Decimal) For Period ifrs-full:NumberOfInstrumentsOtherEquityInstrumentsGranted
695 Fair value of shares granted Concept (Monetary) As Of Credit ifrs-full:WeightedAverageFairValueAtMeasurementDateOtherEquityInstrumentsGranted
696 Fair value of share units previously granted but not yet vested Concept (Monetary) As Of Debit lac:FairValueOfNonvestedSharesGrantedInShareBasedPaymentArrangement
697 Fair value of share units recorded as a share-based payments expense Concept (Monetary) For Period Debit lac:FairValueOfSharesGrantedInShareBasedPaymentArrangement
698 Stock options granted Concept (Decimal) For Period ifrs-full:NumberOfShareOptionsGrantedInSharebasedPaymentArrangement
699 Stock-based compensation expense Concept (Monetary) For Period Debit ifrs-full:ExpenseFromSharebasedPaymentTransactionsWithEmployees
700 Fair value of options granted but not yet vested Concept (Monetary) As Of Credit ifrs-full:WeightedAverageFairValueAtMeasurementDateShareOptionsGranted
701 Weighted average exercise price of share options exercised Concept (Monetary) For Period ifrs-full:WeightedAverageExercisePriceOfShareOptionsExercisedInSharebasedPaymentArrangement
702 Performance based restricted share units vesting description Concept (Text/String) For Period ifrs-full:DescriptionOfVestingRequirementsForSharebasedPaymentArrangement
703 Fair value per PSUs granted Concept (Monetary) As Of lac:FairValueOfShareOtherThanOptionsGranted
704 Rate of earnings on TSR during year 1 Concept (Percent) For Period lac:RateOfEarningsOnShareholderReturnDuringYearOne
705 Rate of earnings on TSR during year 2 Concept (Percent) For Period lac:RateOfEarningsOnShareholderReturnDuringYearTwo
706 Rate of earnings on TSR during year 3 Concept (Percent) For Period lac:RateOfEarningsOnShareholderReturnDuringYearThree
707 Rate of earnings on TSR during 1-3 years Concept (Percent) For Period lac:RateOfEarningsOnShareholderReturnDuringFirstThreeYears
708 100600 - Disclosure - Issued Capital, Equity Compensation, and Warrants - Summary of Changes to Number of Restricted Shares (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIssuedCapitalEquityCompensationAndWarrantsSummaryOfChangesToNumberOfRestrictedSharesDetails
709 Disclosure Of Fair Value Measurement Of Equity [Table] Table

*

*

 ifrs-full:DisclosureOfFairValueMeasurementOfEquityTable
710 Types of share-based payment arrangements [axis] Axis ifrs-full:TypesOfSharebasedPaymentArrangementsAxis
711 Share-based payment arrangements [member] Member ifrs-full:SharebasedPaymentArrangementsMember
712 Restricted Share Units Member lac:RestrictedShareUnitsMember
713 Disclosure Of Fair Value Measurement Of Equity [Line Items] LineItems ifrs-full:DisclosureOfFairValueMeasurementOfEquityLineItems
714 Number of shares outstanding balance Concept (Decimal) As Of ifrs-full:NumberOfOtherEquityInstrumentsOutstandingInSharebasedPaymentArrangement
715 Number of shares granted Concept (Decimal) For Period ifrs-full:NumberOfInstrumentsOtherEquityInstrumentsGranted
716 Number of shares converted into common shares Concept (Decimal) For Period lac:NumberOfOtherEquityInstrumentsConvertedIntoCommonSharesInSharebasedPaymentArrangement
717 Number of shares cancelled or forfeited Concept (Decimal) For Period ifrs-full:NumberOfOtherEquityInstrumentsForfeitedInSharebasedPaymentArrangement
718 Number of shares outstanding balance Concept (Decimal) As Of ifrs-full:NumberOfOtherEquityInstrumentsOutstandingInSharebasedPaymentArrangement
719 100610 - Disclosure - Issued Capital, Equity Compensation, and Warrants - Summary of Changes to Number of Deferred Share Units (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIssuedCapitalEquityCompensationAndWarrantsSummaryOfChangesToNumberOfDeferredShareUnitsDetails
720 Disclosure Of Fair Value Measurement Of Equity [Table] Table

*

*

 ifrs-full:DisclosureOfFairValueMeasurementOfEquityTable
721 Types of share-based payment arrangements [axis] Axis ifrs-full:TypesOfSharebasedPaymentArrangementsAxis
722 Share-based payment arrangements [member] Member ifrs-full:SharebasedPaymentArrangementsMember
723 Deferred Share Units Member lac:DeferredShareUnitsMember
724 Disclosure Of Fair Value Measurement Of Equity [Line Items] LineItems ifrs-full:DisclosureOfFairValueMeasurementOfEquityLineItems
725 Number of shares outstanding balance Concept (Decimal) As Of ifrs-full:NumberOfOtherEquityInstrumentsOutstandingInSharebasedPaymentArrangement
726 Number of shares granted Concept (Decimal) For Period ifrs-full:NumberOfInstrumentsOtherEquityInstrumentsGranted
727 Number of shares converted into common shares Concept (Decimal) For Period lac:NumberOfOtherEquityInstrumentsConvertedIntoCommonSharesInSharebasedPaymentArrangement
728 Number of shares outstanding balance Concept (Decimal) As Of ifrs-full:NumberOfOtherEquityInstrumentsOutstandingInSharebasedPaymentArrangement
729 100620 - Disclosure - Issued Capital, Equity Compensation, and Warrants - Summary of Fair Value of Stock Options Granted by Using Black-Scholes Option Pricing Model (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIssuedCapitalEquityCompensationAndWarrantsSummaryOfFairValueOfStockOptionsGrantedByUsingBlackScholesOptionPricingModelDetails
730 Disclosure Of Issued Capital Equity Compensation And Warrants [Table] Table

*

*

 lac:DisclosureOfIssuedCapitalEquityCompensationAndWarrantsTable
731 Types of share-based payment arrangements [axis] Axis ifrs-full:TypesOfSharebasedPaymentArrangementsAxis
732 Share-based payment arrangements [member] Member ifrs-full:SharebasedPaymentArrangementsMember
733 Stock Option One Member lac:StockOptionOneMember
734 Disclosure Of Issued Capital Equity Compensation And Warrants [Line Items] LineItems lac:DisclosureOfIssuedCapitalEquityCompensationAndWarrantsLineItems
735 Number of options granted (‘000’s) Concept (Decimal) For Period ifrs-full:NumberOfShareOptionsGrantedInSharebasedPaymentArrangement
736 Risk-free interest rate Concept (Percent) For Period ifrs-full:DescriptionOfRiskFreeInterestRateShareOptionsGranted
737 Expected life Concept (Decimal) For Period ifrs-full:DescriptionOfOptionLifeShareOptionsGranted
738 Annualized volatility Concept (Percent) For Period ifrs-full:DescriptionOfExpectedVolatilityShareOptionsGranted
739 Dividend rate Concept (Percent) For Period ifrs-full:ExpectedDividendAsPercentageShareOptionsGranted
740 Fair value per stock option granted (CDN$) Concept (Monetary) As Of lac:FairValueOfShareOptionsGranted
741 Total fair value of stock options granted (CDN$) Concept (Monetary) As Of lac:SumOfFairValueOfStockOptionsGranted
742 100630 - Disclosure - Issued Capital, Equity Compensation, and Warrants - Summary of Stock Options Outstanding and Exercisable (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIssuedCapitalEquityCompensationAndWarrantsSummaryOfStockOptionsOutstandingAndExercisableDetails
743 Disclosure Of Issued Capital Equity Compensation And Warrants [Table] Table

*

*

 lac:DisclosureOfIssuedCapitalEquityCompensationAndWarrantsTable
744 Ranges of exercise prices for outstanding share options [axis] Axis ifrs-full:RangesOfExercisePricesForOutstandingShareOptionsAxis
745 Ranges of exercise prices for outstanding share options [member] Member ifrs-full:RangesOfExercisePricesForOutstandingShareOptionsMember
746 $1.35 - $1.50 Member lac:ExercisePricesRangeOneMember
747 $1.70 - $1.90 Member lac:ExercisePricesRangeTwoMember
748 $2.35 - $3.75 Member lac:ExercisePricesRangeThreeMember
749 $4.80 - $5.00 Member lac:ExercisePricesRangeFourMember
750 $8.05 - $11.05 Member lac:ExercisePricesRangeFiveMember
751 Range [axis] Axis ifrs-full:RangeAxis
752 Ranges [member] Member ifrs-full:RangesMember
753 Bottom of Range Member ifrs-full:BottomOfRangeMember
754 Top of Range Member ifrs-full:TopOfRangeMember
755 Disclosure Of Issued Capital Equity Compensation And Warrants [Line Items] LineItems lac:DisclosureOfIssuedCapitalEquityCompensationAndWarrantsLineItems
756 Exercise price of options outstanding Concept (Monetary) As Of ifrs-full:ExercisePriceOfOutstandingShareOptions
757 Number of options outstanding Concept (Decimal) As Of ifrs-full:NumberOfOutstandingShareOptions
758 Weighted average remaining contractual life of options outstanding (years) Concept (Decimal) As Of ifrs-full:WeightedAverageRemainingContractualLifeOfOutstandingShareOptions
759 Weighted average exercise price of options outstanding Concept (Monetary) As Of ifrs-full:WeightedAverageExercisePriceOfShareOptionsOutstandingInSharebasedPaymentArrangement
760 Number of options exercisable Concept (Decimal) As Of ifrs-full:NumberOfShareOptionsExercisableInSharebasedPaymentArrangement
761 Weighted average exercise price of options exercisable Concept (Monetary) As Of ifrs-full:WeightedAverageExercisePriceOfShareOptionsExercisableInSharebasedPaymentArrangement
762 100640 - Disclosure - Issued Capital, Equity Compensation, and Warrants - Summary of Changes to Stock Options Outstanding (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIssuedCapitalEquityCompensationAndWarrantsSummaryOfChangesToStockOptionsOutstandingDetails
763 Implied Table Table

*

*

 implied:Table
764 Disclosure Of Changes To Stock Options Outstanding [Abstract] Abstract lac:DisclosureOfChangesToStockOptionsOutstandingAbstract
765 Number of Options, Balance Outstanding Concept (Decimal) As Of ifrs-full:NumberOfOutstandingShareOptions
766 Number of Options, Granted Concept (Decimal) For Period ifrs-full:NumberOfShareOptionsGrantedInSharebasedPaymentArrangement
767 Number of Options, Exercised Concept (Decimal) For Period ifrs-full:NumberOfShareOptionsExercisedInSharebasedPaymentArrangement
768 Number of Options, Forfeited Concept (Decimal) For Period ifrs-full:NumberOfShareOptionsForfeitedInSharebasedPaymentArrangement
769 Number of Options, Balance Outstanding Concept (Decimal) As Of ifrs-full:NumberOfOutstandingShareOptions
770 Number of Options, Expired Concept (Decimal) For Period ifrs-full:NumberOfShareOptionsExpiredInSharebasedPaymentArrangement
771 Weighted Average Exercise Price, Balance Outstanding Concept (Monetary) As Of ifrs-full:WeightedAverageExercisePriceOfShareOptionsOutstandingInSharebasedPaymentArrangement
772 Weighted Average Exercise Price, Granted Concept (Monetary) For Period ifrs-full:WeightedAverageExercisePriceOfShareOptionsGrantedInSharebasedPaymentArrangement
773 Weighted Average Exercise Price, Exercised Concept (Monetary) For Period ifrs-full:WeightedAverageExercisePriceOfShareOptionsExercisedInSharebasedPaymentArrangement
774 Weighted Average Exercise Price, Forfeited Concept (Monetary) For Period ifrs-full:WeightedAverageExercisePriceOfShareOptionsForfeitedInSharebasedPaymentArrangement
775 Weighted Average Exercise Price, Balance Outstanding Concept (Monetary) As Of ifrs-full:WeightedAverageExercisePriceOfShareOptionsOutstandingInSharebasedPaymentArrangement
776 Weighted Average Exercise Price, Expired Concept (Monetary) For Period ifrs-full:WeightedAverageExercisePriceOfShareOptionsExpiredInSharebasedPaymentArrangement
777 100650 - Disclosure - Issued Capital and Equity Incentive Plan - Summary of Fair Value of Performance Awards Granted by Using Monte Carlo Simulation Model (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIssuedCapitalAndEquityIncentivePlanSummaryOfFairValueOfPerformanceAwardsGrantedByUsingMonteCarloSimulationModelDetails
778 Disclosure Of Issued Capital Equity Compensation And Warrants [Table] Table

*

*

 lac:DisclosureOfIssuedCapitalEquityCompensationAndWarrantsTable
779 Types of share-based payment arrangements [axis] Axis ifrs-full:TypesOfSharebasedPaymentArrangementsAxis
780 Share-based payment arrangements [member] Member ifrs-full:SharebasedPaymentArrangementsMember
781 Performance Share Units Member lac:PerformanceShareUnitsMember
782 Disclosure Of Issued Capital Equity Compensation And Warrants [Line Items] LineItems lac:DisclosureOfIssuedCapitalEquityCompensationAndWarrantsLineItems
783 Number of shares granted Concept (Decimal) For Period ifrs-full:NumberOfInstrumentsOtherEquityInstrumentsGranted
784 Correlation coefficient between the peer group companies Concept (Percent) As Of lac:CorrelationCoefficientPercentage
785 Risk-free interest rate Concept (Percent) As Of lac:DescriptionOfRiskFreeInterestRateOtherThanShareOptionsGranted
786 Dividend rate Concept (Percent) As Of lac:DividendYieldAsPercentageOtherThanShareOptionsGranted
787 Annualized volatility Concept (Percent) As Of lac:DescriptionOfAnnualizedVolatilityOtherThanShareOptionsGranted
788 Peer Group average volatility Concept (Percent) As Of lac:DescriptionOfPeerGroupAverageVolatilityOtherThanShareOptionsGranted
789 Estimated forfeiture rate Concept (Percent) As Of lac:EstimatedForfeitureAsPercentageOtherThanShareOptionsGranted
790 Fair value per PSU granted (CDN$) Concept (Monetary) As Of lac:FairValueOfShareOtherThanOptionsGranted
791 Total fair value of PSUs granted, prior to forfeiture rate adjustment (CDN$) Concept (Monetary) As Of lac:SumOfFairValueOfSharesOtherThanOptionsGrantedPriorToForfeitureRateAdjustment
792 100660 - Disclosure - Issued Capital and Equity Incentive Plan -Summary of Changes to Number of RS-Ps (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIssuedCapitalAndEquityIncentivePlanSummaryOfChangesToNumberOfRSPsDetails
793 Disclosure Of Fair Value Measurement Of Equity [Table] Table

*

*

 ifrs-full:DisclosureOfFairValueMeasurementOfEquityTable
794 Types of share-based payment arrangements [axis] Axis ifrs-full:TypesOfSharebasedPaymentArrangementsAxis
795 Share-based payment arrangements [member] Member ifrs-full:SharebasedPaymentArrangementsMember
796 Performance Share Units Member lac:PerformanceShareUnitsMember
797 Disclosure Of Fair Value Measurement Of Equity [Line Items] LineItems ifrs-full:DisclosureOfFairValueMeasurementOfEquityLineItems
798 Number of shares outstanding balance Concept (Decimal) As Of ifrs-full:NumberOfOtherEquityInstrumentsOutstandingInSharebasedPaymentArrangement
799 Number of shares granted Concept (Decimal) For Period ifrs-full:NumberOfInstrumentsOtherEquityInstrumentsGranted
800 Number of shares outstanding balance Concept (Decimal) As Of ifrs-full:NumberOfOtherEquityInstrumentsOutstandingInSharebasedPaymentArrangement
801 100670 - Disclosure - Issued Capital, Equity Compensation, and Warrants - Summary of Changes in Number of Share Purchase Warrants (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIssuedCapitalEquityCompensationAndWarrantsSummaryOfChangesInNumberOfSharePurchaseWarrantsDetails
802 Disclosure Of Changes In Number Of Share Purchase Warrants [Table] Table

*

*

 lac:DisclosureOfChangesInNumberOfSharePurchaseWarrantsTable
803 Classes of assets [axis] Axis ifrs-full:ClassesOfAssetsAxis
804 Assets [member] Member ifrs-full:ClassesOfAssetsMember
805 Warrants Member lac:SharePurchaseWarrantsMember
806 Disclosure Of Changes In Number Of Share Purchase Warrants [Line Items] LineItems lac:DisclosureOfChangesInNumberOfSharePurchaseWarrantsLineItems
807 Number of shares outstanding balance Concept (Decimal) As Of ifrs-full:NumberOfOtherEquityInstrumentsOutstandingInSharebasedPaymentArrangement
808 Number of Warrants, Exercised Concept (Decimal) For Period ifrs-full:NumberOfOtherEquityInstrumentsExercisedOrVestedInSharebasedPaymentArrangement
809 Number of Warrants, Expired Concept (Decimal) For Period ifrs-full:NumberOfOtherEquityInstrumentsExpiredInSharebasedPaymentArrangement
810 Number of shares outstanding balance Concept (Decimal) As Of ifrs-full:NumberOfOtherEquityInstrumentsOutstandingInSharebasedPaymentArrangement
811 Weighted Average Exercise Price, Balance Concept (Monetary) As Of ifrs-full:WeightedAverageExercisePriceOfOtherEquityInstrumentsOutstandingInSharebasedPaymentArrangement
812 Weighted Average Exercise Price, Exercised Concept (Monetary) For Period ifrs-full:WeightedAverageExercisePriceOfOtherEquityInstrumentsExercisedOrVestedInSharebasedPaymentArrangement
813 Weighted Average Exercise Price, Expired Concept (Monetary) For Period ifrs-full:WeightedAverageExercisePriceOfOtherEquityInstrumentsExpiredInSharebasedPaymentArrangement
814 Weighted Average Exercise Price, Balance Concept (Monetary) As Of ifrs-full:WeightedAverageExercisePriceOfOtherEquityInstrumentsOutstandingInSharebasedPaymentArrangement
815 100680 - Disclosure - Related Party Transactions - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureRelatedPartyTransactionsAdditionalInformationDetails
816 Disclosure Of Transactions Between Related Parties [Table] Table

*

*

 ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesTable
817 Types of contracts [axis] Axis ifrs-full:TypesOfContractsAxis
818 Types of contracts [member] Member ifrs-full:TypesOfContractsMember
819 Cauchari-Olaroz Project Member lac:CauchariOlarozProjectMember
820 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
821 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
822 Minera Exar S.A. Member lac:MineraExarMember
823 Non Executive Directors Member lac:NonExecutiveDirectorsMember
824 Committee Chair Member lac:CommitteeChairMember
825 Company's Audit Committee Chair Member lac:CompanysAuditCommitteeChairMember
826 Committee Members Member lac:CommitteeMembersMember
827 Company's Board Chair Member Member lac:CompanysBoardChairMember
828 Excess Of Six Meetings Per Year Member lac:ExcessOfSixMeetingsPerYearMember
829 Special Committee Member lac:SpecialCommitteeMember
830 Excess of Five Meetings Per Year Member lac:ExcessOfFiveMeetingsPerYearMember
831 Counterparties [axis] Axis ifrs-full:CounterpartiesAxis
832 Counterparties [member] Member ifrs-full:CounterpartiesMember
833 Magna Construcciones S.R.L Member lac:MagnaConstruccionesSRLMember
834 Range [axis] Axis ifrs-full:RangeAxis
835 Ranges [member] Member ifrs-full:RangesMember
836 Bottom of Range Member ifrs-full:BottomOfRangeMember
837 Top of Range Member ifrs-full:TopOfRangeMember
838 Disclosure Of Transactions Between Related Parties [Line Items] LineItems ifrs-full:DisclosureOfTransactionsBetweenRelatedPartiesLineItems
839 Total construction services contract value Concept (Monetary) For Period Debit lac:ConstructionServiceContractValue
840 Payment of base annual fees Concept (Monetary) For Period Debit ifrs-full:DirectorsRemunerationExpense
841 Remunerations payable in DSU's Concept (Monetary) For Period Debit lac:RenumerationsPayableInDSUs
842 Contractual or other commitments from related party transactions Concept (Monetary) For Period ifrs-full:CommitmentsMadeByEntityRelatedPartyTransactions
843 100690 - Disclosure - Related Party Transactions - Summary of Compensation of Key Management (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureRelatedPartyTransactionsSummaryOfCompensationOfKeyManagementDetails
844 Implied Table Table

*

*

 implied:Table
845 Related Party Transactions [Abstract] Abstract ifrs-full:RelatedPartyTransactionsAbstract
846 Stock-based compensation Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensationSharebasedPayment
847 Salaries, benefits and directors’ fees included in general and administrative expenses Concept (Monetary) For Period Debit lac:SalariesBenefitsAndDirectorsFeesIncludedInGeneralAndAdministrativeExpenses
848 Salaries and benefits included in exploration expenditures Concept (Monetary) For Period Debit lac:SalariesAndBenefitsIncludedInExplorationExpenditures
849 Salaries and benefits capitalized to Investment in the Joint Venture Concept (Monetary) For Period Debit lac:SalariesAndBenefitsCapitalizedToInvestmentInJointVenture
850 Total remuneration Concept (Monetary) For Period Debit ifrs-full:KeyManagementPersonnelCompensation
851 Total due to directors and executive team Concept (Monetary) As Of Debit lac:AmountDueToDirectorsAndExecutiveTeam
852 100700 - Disclosure - General and Administrative Expenses - Summary of Company's General and Administrative Expenses (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureGeneralAndAdministrativeExpensesSummaryOfCompanySGeneralAndAdministrativeExpensesDetails
853 Disclosure Of General And Administrative Expenses [Table] Table

*

*

 lac:DisclosureOfGeneralAndAdministrativeExpensesTable
854 General And Administrative Expenses Axis lac:GeneralAndAdministrativeExpensesAxis
855 General And Administrative Expenses Member Member lac:GeneralAndAdministrativeExpensesMember
856 Salaries, Benefits and Directors Fees Member lac:SalariesBenefitsAndDirectorsFeesMember
857 Office and Administration Member lac:OfficeAndAdministrationMember
858 Professional Fees Member lac:ProfessionalFeesMember
859 Regulatory and Filing Fees Member lac:RegulatoryAndFilingFeesMember
860 Travel Member lac:TravelMember
861 Organoclay Marketing Expenses Member lac:OrganoclayMarketingExpensesMember
862 Depreciation Member lac:DepreciationMember
863 Investor Relations Member lac:InvestorRelationsMember
864 Disclosure Of General And Administrative Expenses [Line Items] LineItems lac:DisclosureOfGeneralAndAdministrativeExpensesLineItems
865 General and administrative expenses Concept (Monetary) For Period Debit ifrs-full:GeneralAndAdministrativeExpense
866 100710 - Disclosure - Commitments and Contingencies - Schedule of Other Commitments (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureCommitmentsAndContingenciesScheduleOfOtherCommitmentsDetails
867 Disclosure Of Commitments [Table] Table

*

*

 lac:DisclosureOfCommitmentsTable
868 Maturity [axis] Axis ifrs-full:MaturityAxis
869 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
870 Not Later Than 1 Year Member ifrs-full:NotLaterThanOneYearMember
871 Later Than 1 Year and Not Later Than 5 Years Member ifrs-full:LaterThanOneYearAndNotLaterThanFiveYearsMember
872 Later Than 5 Years Member ifrs-full:LaterThanFiveYearsMember
873 Disclosure Of Commitments [Line Items] LineItems lac:DisclosureOfCommitmentsLineItems
874 Rent of office spaces Concept (Monetary) As Of Credit lac:RentOnOfficeSpace
875 100720 - Disclosure - Exploration Expenditures - Summary of Company's Exploration Expenditures (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureExplorationExpendituresSummaryOfCompanySExplorationExpendituresDetails
876 Disclosure Of Exploration Expenditures [Table] Table

*

*

 lac:DisclosureOfExplorationExpendituresTable
877 Segments [axis] Axis ifrs-full:SegmentsAxis
878 Segments [member] Member ifrs-full:SegmentsMember
879 Thacker Pass Member lac:ThackerPassMember
880 Cauchari-Olaroz Member lac:CauchariOlarozMember
881 Equity Securities By Industry Axis us-gaap:EquitySecuritiesByIndustryAxis
882 Equity Securities Industry Member Member us-gaap:EquitySecuritiesIndustryMember
883 Drilling and Geological Expenses Member lac:DrillingAndGeologicalExpensesMember
884 Permitting and Environmental Member lac:PermittingAndEnvironmentalMember
885 Engineering Member lac:EngineeringMember
886 Geological, Consulting and Salaries Member lac:GeologicalAndConsultingMember
887 Field Supplies and Other Member lac:FieldSuppliesAndOtherMember
888 Lithium Demo Plant Equipment Depreciation and Loss on Disposal Member lac:LithiumDemoPlantEquipmentDepreciationAndLossOnDisposalMember
889 Disclosure Of Exploration Expenditures [Line Items] LineItems lac:DisclosureOfExplorationExpendituresLineItems
890 Exploration expenditures Concept (Monetary) For Period Debit ifrs-full:ExpenseArisingFromExplorationForAndEvaluationOfMineralResources
891 100730 - Disclosure - Segmented Information - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSegmentedInformationAdditionalInformationDetails
892 Implied Table Table

*

*

 implied:Table
893 Disclosure Of Operating Segments [Abstract] Abstract ifrs-full:DisclosureOfOperatingSegmentsAbstract
894 Number of operating segments Concept (Integer) For Period lac:NumberOfOperatingSegments1
895 Number of geographic segments Concept (Integer) For Period lac:NumberOfGeographicSegments
896 100740 - Disclosure - Segmented Information - Summary of Reportable Segments (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSegmentedInformationSummaryOfReportableSegmentsDetails
897 Disclosure Of Operating Segments [Table] Table

*

*

 ifrs-full:DisclosureOfOperatingSegmentsTable
898 Segment consolidation items [axis] Axis ifrs-full:SegmentConsolidationItemsAxis
899 Entity's total for segment consolidation items [member] Member ifrs-full:EntitysTotalForSegmentConsolidationItemsMember
900 Operating Segments Member ifrs-full:OperatingSegmentsMember
901 Corporate Member lac:Corporate1Member
902 Segments [axis] Axis ifrs-full:SegmentsAxis
903 Segments [member] Member ifrs-full:SegmentsMember
904 Organoclay Plant Member lac:OrganoclayPlantMember
905 Thacker Pass Member lac:ThackerPassMember
906 Cauchari-Olaroz Member lac:CauchariOlarozMember
907 Disclosure Of Operating Segments [Line Items] LineItems ifrs-full:DisclosureOfOperatingSegmentsLineItems
908 Property, plant and equipment Concept (Monetary) As Of Debit ifrs-full:PropertyPlantAndEquipment
909 Capital assets Concept (Monetary) As Of Debit lac:CapitalAssets
910 Exploration and evaluation assets Concept (Monetary) As Of Debit ifrs-full:IntangibleExplorationAndEvaluationAssets
911 Total assets Concept (Monetary) As Of Debit ifrs-full:Assets
912 Total liabilities Concept (Monetary) As Of Credit ifrs-full:Liabilities
913 Property, plant and equipment additions Concept (Monetary) For Period Debit ifrs-full:AdditionsOtherThanThroughBusinessCombinationsPropertyPlantAndEquipment
914 Sales Concept (Monetary) For Period Credit ifrs-full:Revenue
915 Inventory write-down Concept (Monetary) For Period ifrs-full:InventoryWritedown2011
916 Net loss Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
917 Exploration expenditures Concept (Monetary) For Period Debit ifrs-full:ExpenseArisingFromExplorationForAndEvaluationOfMineralResources
918 Depreciation Concept (Monetary) For Period Debit ifrs-full:DepreciationExpense
919 Organoclay research and development Concept (Monetary) For Period Debit ifrs-full:ResearchAndDevelopmentExpense
920 100750 - Disclosure - Segmented Information - Schedule of Non-current Assets and Revenue by Geographical Segment (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSegmentedInformationScheduleOfNonCurrentAssetsAndRevenueByGeographicalSegmentDetails
921 Disclosure Of Operating Segments [Table] Table

*

*

 ifrs-full:DisclosureOfOperatingSegmentsTable
922 Segments [axis] Axis ifrs-full:SegmentsAxis
923 Segments [member] Member ifrs-full:SegmentsMember
924 Canada Member lac:CanadaSegmentMember
925 United States Member lac:UnitedStatesSegmentMember
926 Germany Member lac:GermanySegmentMember
927 Argentina Member lac:ArgentinaSegmentMember
928 Disclosure Of Operating Segments [Line Items] LineItems ifrs-full:DisclosureOfOperatingSegmentsLineItems
929 NON-CURRENT ASSETS Abstract ifrs-full:NoncurrentAssetsAbstract
930 Non-current assets Concept (Monetary) As Of Debit lac:NonCurrentAssetsAttributedToGeographicalLocationsExcludeDeferredIncomeTaxAssetsAndFinancialAndOtherAssets
931 Revenue Abstract ifrs-full:RevenueAbstract
932 ORGANOCLAY SALES Concept (Monetary) For Period Credit ifrs-full:Revenue
933 100760 - Disclosure - Supplemental Disclosure with Respect to Cash Flows - Supplementary Disclosure of Company's Non Cash Transactions (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSupplementalDisclosureWithRespectToCashFlowsSupplementaryDisclosureOfCompanySNonCashTransactionsDetails
934 Implied Table Table

*

*

 implied:Table
935 Supplemental Information With Respect To Cash Flows [Abstract] Abstract lac:SupplementalInformationWithRespectToCashFlowsAbstract
936 Accounts payable related to property, plant and equipment Concept (Monetary) For Period Credit lac:NonCashTransactionAccountsPayableRelatedToPropertyPlantAndEquipment
937 Accounts payable related to inventories Concept (Monetary) For Period Credit lac:NonCashTransactionAccountsPayableRelatedToInventories
938 Accounts payable related to financings Concept (Monetary) For Period Credit lac:NonCashTransactionAccountsPayableRelatedToFinancings
939 Interest/finance charges paid Concept (Monetary) For Period Credit lac:NonCashTransactionInterestFinanceChargesPaid
940 RSUs and DSUs granted in lieu of deferred salaries and directors’ fees Concept (Monetary) For Period Credit lac:NonCashTransactionRestrictedStockUnitsAndDeferredShareUnitsGrantedInLieuOfDeferredSalariesAndDirectorsFees
941 Assets acquired under finance leases Concept (Monetary) For Period Credit lac:NonCashTransactionAssetsAcquiredUnderFinanceLeases
942 Income taxes paid Concept (Monetary) For Period Credit lac:NonCashTransactionIncomeTaxesPaid
943 100770 - Disclosure - Income Taxes - Summary of Reconciliation of Income Taxes at Canadian Statutory Rates with Reported Taxes (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIncomeTaxesSummaryOfReconciliationOfIncomeTaxesAtCanadianStatutoryRatesWithReportedTaxesDetails
944 Implied Table Table

*

*

 implied:Table
945 Reconciliation Of Accounting Profit Multiplied By Applicable Tax Rates [Abstract] Abstract ifrs-full:ReconciliationOfAccountingProfitMultipliedByApplicableTaxRatesAbstract
946 Loss for the year Concept (Monetary) For Period Credit ifrs-full:ProfitLoss
947 Expected income tax recovery Concept (Monetary) For Period Debit lac:ExpectedIncomeTaxRecovery
948 Items not deductible for income tax purposes Concept (Monetary) For Period Debit lac:TaxEffectOfBenefitExpenseNotDeductibleInDeterminingTaxableProfitTaxLossIncome
949 Effect of change in deferred income tax rate Concept (Monetary) For Period Debit ifrs-full:TaxEffectFromChangeInTaxRate
950 Effect of higher (lower) tax rate in foreign jurisdiction Concept (Monetary) For Period Debit ifrs-full:TaxEffectOfForeignTaxRates
951 Change in unrecognized deferred tax assets and other Concept (Monetary) For Period Credit lac:IncreaseDecreaseInUnrecognizedDeferredTaxAssetsAndOther
952 Deferred income tax (expense)/recovery Concept (Monetary) For Period ifrs-full:DeferredTaxExpenseIncomeRecognisedInProfitOrLoss
953 100780 - Disclosure - Income Taxes - Summary of Significant Components of Company's Unrecognized Deferred Tax Assets (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIncomeTaxesSummaryOfSignificantComponentsOfCompanySUnrecognizedDeferredTaxAssetsDetails
954 Disclosure Of Temporary Difference Unused Tax Losses And Unused Tax Credits [Table] Table

*

*

 ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsTable
955 Temporary difference, unused tax losses and unused tax credits [axis] Axis ifrs-full:TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsAxis
956 Temporary difference, unused tax losses and unused tax credits [member] Member ifrs-full:TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsMember
957 Tax Loss Carryforwards Member lac:TaxLossCarryforwardsMember
958 Exploration and Evaluation Assets Member ifrs-full:ExplorationAndEvaluationAssetsMember
959 Financing Costs Member lac:FinancingCostsMember
960 Capital Assets Member lac:CapitalAssetsMember
961 Other Member ifrs-full:OtherTemporaryDifferencesMember
962 Disclosure of Temporary Difference Unused Tax Losses and Unused Tax Credits [Line Items] LineItems ifrs-full:DisclosureOfTemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsLineItems
963 Tax loss carryforwards Concept (Monetary) As Of Debit lac:UnrecognizedDeferredTaxAssets
964 100790 - Disclosure - Income Taxes - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureIncomeTaxesAdditionalInformationDetails
965 Implied Table Table

*

*

 implied:Table
966 Major Components Of Tax Expense Income [Abstract] Abstract ifrs-full:MajorComponentsOfTaxExpenseIncomeAbstract
967 Non-capital loss carryforwards Concept (Monetary) As Of Debit lac:NonCapitalLossCarryforwards
968 Non-capital loss carryforwards expiration year period Concept (Text/String) For Period lac:DescriptionOfNonCapitalLossCarryforwardsExpirationYearPeriod
969 100800 - Disclosure - Financial Instruments - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsAdditionalInformationDetails
970 Disclosure Of Financial Instruments [Table] Table

*

*

 ifrs-full:DisclosureOfFinancialInstrumentsTable
971 Types of risks [axis] Axis ifrs-full:TypesOfRisksAxis
972 Risks [member] Member ifrs-full:TypesOfRisksMember
973 Credit Risk Member ifrs-full:CreditRiskMember
974 Currency Risk Member ifrs-full:CurrencyRiskMember
975 Classes of financial instruments [axis] Axis ifrs-full:ClassesOfFinancialInstrumentsAxis
976 Financial instruments, class [member] Member ifrs-full:ClassesOfFinancialInstrumentsMember
977 Prepaids and Deposits Member lac:PrepaidsAndDepositsMember
978 Disclosure Of Financial Instruments [Line Items] LineItems ifrs-full:DisclosureOfFinancialInstrumentsLineItems
979 Credit sales receivables Concept (Monetary) As Of Debit ifrs-full:OtherReceivables
980 Amount on receivables, prepaids and deposits Concept (Monetary) As Of ifrs-full:AmountByWhichLoansOrReceivablesRelatedCreditDerivativesOrSimilarInstrumentsMitigateMaximumExposureToCreditRisk
981 Cash and cash equivalents Concept (Monetary) As Of Debit ifrs-full:CashAndCashEquivalents
982 Current liabilities Concept (Monetary) As Of Credit ifrs-full:CurrentLiabilities
983 Cash and cash equivalents held in USD Concept (Monetary) For Period Debit lac:AmountOfCashAndCashEquivalentsHeldInUSD
984 Credit facility denominated in USD Concept (Monetary) As Of Credit lac:DrawnBorrowingFacilities
985 Foreign exchange rate Concept (Decimal) For Period ifrs-full:AverageForeignExchangeRate
986 Foreign exchange gain/(loss) Concept (Monetary) For Period Credit ifrs-full:GainsLossesOnExchangeDifferencesOnTranslationRecognisedInProfitOrLoss
987 100810 - Disclosure - Financial instruments - Summary of Maturities for Financial Liabilities on Undiscounted Basis (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureFinancialInstrumentsSummaryOfMaturitiesForFinancialLiabilitiesOnUndiscountedBasisDetails
988 Disclosure Of Maturity Analysis For Nonderivative Financial Liabilities [Table] Table

*

*

 ifrs-full:DisclosureOfMaturityAnalysisForNonderivativeFinancialLiabilitiesTable
989 Types of financial liabilities [axis] Axis ifrs-full:TypesOfFinancialLiabilitiesAxis
990 Financial liabilities, type [member] Member ifrs-full:FinancialLiabilitiesTypeMember
991 Credit Facility Member lac:CreditFacilityMember
992 Accounts Payable and Accrued Liabilities Member lac:AccountsPayablesAndAccruedLiabilitiesMember
993 Long-term Borrowing Member ifrs-full:LongtermBorrowingsMember
994 Obligation Under Finance Leases Member lac:ObligationUnderFinanceLeasesMember
995 Obligation Under Car Leases Member lac:ObligationUnderCarLeaseMember
996 Maturity [axis] Axis ifrs-full:MaturityAxis
997 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
998 2019 Member ifrs-full:NotLaterThanOneYearMember
999 2020 Member ifrs-full:LaterThanOneYearMember
1000 2021 and Later Member lac:LaterThanTwoYearsAndThereafterMember
1001 Disclosure Of Maturity Analysis For Nonderivative Financial Liabilities [Line Items] LineItems ifrs-full:DisclosureOfMaturityAnalysisForNonderivativeFinancialLiabilitiesLineItems
1002 Financial liabilities on undiscounted basis ,Total Concept (Monetary) As Of Credit ifrs-full:NonderivativeFinancialLiabilitiesUndiscountedCashFlows
1003 100820 - Disclosure - Impairment of Non-current Assets - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureImpairmentOfNonCurrentAssetsAdditionalInformationDetails
1004 Impairment Of Non Current Assets [Table] Table

*

*

 lac:ImpairmentOfNonCurrentAssetsTable
1005 Maturity [axis] Axis ifrs-full:MaturityAxis
1006 Aggregated time bands [member] Member ifrs-full:AggregatedTimeBandsMember
1007 2019 Member ifrs-full:NotLaterThanOneYearMember
1008 2020 Member ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMember
1009 2021 Member ifrs-full:LaterThanTwoYearsAndNotLaterThanThreeYearsMember
1010 2022 Member ifrs-full:LaterThanOneYearAndNotLaterThanFiveYearsMember
1011 Measurement [axis] Axis ifrs-full:MeasurementAxis
1012 Aggregated measurement [member] Member ifrs-full:AggregatedMeasurementMember
1013 1% decrease in sales Member lac:DecreaseInSalesMember
1014 1% increase in discount rate Member lac:IncreaseInDiscountMember
1015 Impairment Of Non Current Assets [Line Items] LineItems lac:ImpairmentOfNonCurrentAssetsLineItems
1016 Non-cash impairment loss Concept (Monetary) For Period ifrs-full:ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipment
1017 EBITDA margin Concept (Percent) For Period lac:EarningsBeforeInterestTaxDepreciationAndAmortizationMargin
1018 Sales growth Concept (Percent) For Period lac:SalesGrowthRate
1019 After tax real discount rate Concept (Percent) For Period lac:AfterTaxDiscountRate
1020 Decrease in sales Concept (Percent) For Period lac:DecreaseSalesPercentage
1021 Additional impairment charges Concept (Monetary) For Period Debit lac:AdditionalImpairmentCharges
1022 Increase in discount rate Concept (Percent) For Period lac:IncreaseInDiscountRate
1023 100830 - Disclosure - Subsequent Events - Additional Information (Details) Network

*

*

 http://www.lithiumamericas.com/20181231/taxonomy/role/DisclosureSubsequentEventsAdditionalInformationDetails
1024 Disclosure Of Nonadjusting Events After Reporting Period [Table] Table

*

*

 ifrs-full:DisclosureOfNonadjustingEventsAfterReportingPeriodTable
1025 Joint ventures [axis] Axis ifrs-full:JointVenturesAxis
1026 Entity's total for joint ventures [member] Member ifrs-full:EntitysTotalForJointVenturesMember
1027 Minera Exar S.A. Member lac:MineraExarMember
1028 Non-adjusting events after reporting period [axis] Axis ifrs-full:NonadjustingEventsAfterReportingPeriodAxis
1029 Non-adjusting events after reporting period [member] Member ifrs-full:NonadjustingEventsMember
1030 Events after reporting period Member lac:EventsAfterReportingPeriodMember
1031 Borrowings by name [axis] Axis ifrs-full:BorrowingsByNameAxis
1032 Borrowings by name [member] Member ifrs-full:BorrowingsByNameMember
1033 Credit Facility Member lac:CreditFacilityMember
1034 Associates [axis] Axis ifrs-full:SignificantInvestmentsInAssociatesAxis
1035 Entity's total for associates [member] Member ifrs-full:EntitysTotalForAssociatesMember
1036 Ganfeng Member lac:GanfengInvestmentAgreementMember
1037 Range [axis] Axis ifrs-full:RangeAxis
1038 Ranges [member] Member ifrs-full:RangesMember
1039 Bottom of Range Member ifrs-full:BottomOfRangeMember
1040 Top of Range Member ifrs-full:TopOfRangeMember
1041 Segments [axis] Axis ifrs-full:SegmentsAxis
1042 Segments [member] Member ifrs-full:SegmentsMember
1043 Cauchari-Olaroz Member lac:CauchariOlarozMember
1044 Categories of related parties [axis] Axis ifrs-full:CategoriesOfRelatedPartiesAxis
1045 Entity's total for related parties [member] Member ifrs-full:EntitysTotalForRelatedPartiesMember
1046 Lithium Americas Holding Member ifrs-full:ParentMember
1047 Types of contracts [axis] Axis ifrs-full:TypesOfContractsAxis
1048 Types of contracts [member] Member ifrs-full:TypesOfContractsMember
1049 JEMSE Arrangement Member lac:JEMSEArrangementMember
1050 Disclosure Of Nonadjusting Events After Reporting Period [Line Items] LineItems ifrs-full:DisclosureOfNonadjustingEventsAfterReportingPeriodLineItems
1051 Additional borrowings obtained from drawdown of line of credit facility Concept (Monetary) As Of Credit lac:AdditionalBorrowingsObtainedFromLineOfCreditFacility
1052 Drawdowns From The Credit Facility Concept (Monetary) For Period Debit lac:DrawdownsFromTheCreditFacility
1053 Loans to Joint Venture Concept (Monetary) As Of Debit ifrs-full:NoncurrentLoansAndReceivables
1054 Number of shares newly issued Concept (Shares) As Of ifrs-full:NumberOfSharesIssued
1055 Cash consideration Concept (Monetary) For Period Credit ifrs-full:PortionOfConsiderationPaidReceivedConsistingOfCashAndCashEquivalents
1056 Ownership interest in joint venture Concept (Percent) For Period ifrs-full:ProportionOfOwnershipInterestInJointVenture
1057 Rights granted to acquire equity interest in joint venture, percentage Concept (Percent) For Period lac:RightsGrantedToAcquireEquityInterestInJointVenturePercentage

*

*