ALK


Line plots across dimensions of each concept
Tables

Table of contents



us-gaap:CommonStockValue

us-gaap:CommonStockParOrStatedValuePerShare

us-gaap:CommonStockSharesIssued

us-gaap:CommonStockSharesOutstanding
us-gaap:StatementEquityComponents

us-gaap:CommonStockSharesAuthorized

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted
us-gaap:ContractWithCustomerSalesChannel
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
us-gaap:ProductOrService, us-gaap:ContractWithCustomerSalesChannel
us-gaap:ProductOrService
us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:Revenues
us-gaap:StatementBusinessSegments

us-gaap:CostsAndExpenses
us-gaap:StatementBusinessSegments

us-gaap:OperatingIncomeLoss

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:NonoperatingIncomeExpense
us-gaap:StatementBusinessSegments

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxesPaidNet

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:NetIncomeLoss
us-gaap:StatementEquityComponents

us-gaap:Assets
us-gaap:StatementBusinessSegments

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents

us-gaap:AssetsCurrent

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:ReceivablesNetCurrent
us-gaap:ContractWithCustomerSalesChannel

us-gaap:InventoryNet

us-gaap:PrepaidExpenseAndOtherAssetsCurrent

us-gaap:PropertyPlantAndEquipmentGross

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:Goodwill

us-gaap:IntangibleAssetsNetExcludingGoodwill

us-gaap:OtherAssetsNoncurrent

us-gaap:LiabilitiesCurrent

us-gaap:AccountsPayableCurrent

us-gaap:LiabilitiesNoncurrent

us-gaap:LongTermDebt
us-gaap:DebtInstrument
us-gaap:LongtermDebtType

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents

us-gaap:CommonStockValue

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:TreasuryStockValue

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetIncomeLoss
us-gaap:StatementEquityComponents

us-gaap:DepreciationDepletionAndAmortization

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:RepaymentsOfLongTermDebt

us-gaap:PaymentsOfDividends

us-gaap:PaymentsOfDividends

us-gaap:PaymentsForRepurchaseOfCommonStock

us-gaap:RepaymentsOfLongTermDebt

us-gaap:ShareBasedCompensation

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
us-gaap:AircraftType
alk:AircraftPermanentlyParked
us-gaap:ContractWithCustomerSalesChannel
alk:ContractwithCustomerLiabilityIncreaseFromIssuanceofCredits

alk:NumberOfMainlineAircraftParked
us-gaap:SubsequentEventType

alk:OperatingExpensesExcludingFuel
us-gaap:StatementBusinessSegments

alk:OtherNonoperatingIncomeExpenseOther
us-gaap:StatementBusinessSegments

alk:RegionalCarrierExpense

alk:SpecialItemsImpairmentChargesAndOther
us-gaap:StatementEquityComponents
us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:AircraftMaintenanceMaterialsAndRepairs

us-gaap:AircraftRental

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs

us-gaap:AssetImpairmentCharges
us-gaap:AircraftType
us-gaap:AircraftType, us-gaap:ImpairedLongLivedAssetsHeldAndUsedByType
us-gaap:ImpairedLongLivedAssetsHeldAndUsedByType

us-gaap:BusinessCombinationAcquisitionRelatedCosts

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:CommonStockDividendsPerShareDeclared
us-gaap:SubsequentEventType
us-gaap:ContractWithCustomerSalesChannel
us-gaap:ContractWithCustomerLiabilityRevenueRecognized
us-gaap:ProductOrService, us-gaap:ContractWithCustomerSalesChannel

us-gaap:CostOfServicesCatering
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanInterestCost
us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanServiceCost
us-gaap:StatementEquityComponents
us-gaap:DividendsCash

us-gaap:FuelCosts
us-gaap:StatementBusinessSegments

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
us-gaap:StatementBusinessSegments

us-gaap:IncreaseDecreaseInContractWithCustomerLiability

us-gaap:IncreaseDecreaseInDeferredIncomeTaxes

us-gaap:IncreaseDecreaseInDeferredRevenue

us-gaap:InterestCostsCapitalizedAdjustment

us-gaap:InterestCostsIncurred
us-gaap:StatementBusinessSegments

us-gaap:InterestPaidCapitalized
us-gaap:StatementBusinessSegments

us-gaap:InterestPaidNet

us-gaap:InvestmentIncomeInterest
us-gaap:StatementBusinessSegments

us-gaap:LaborAndRelatedExpense

us-gaap:LandingFeesAndOtherRentals

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax

us-gaap:OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax

us-gaap:OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax
us-gaap:StatementEquityComponents

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax

us-gaap:OtherComprehensiveIncomeLossTax

us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax

us-gaap:OtherCostAndExpenseOperating

us-gaap:OtherLaborRelatedExpenses

us-gaap:OtherOperatingActivitiesCashFlowStatement

us-gaap:PaymentsForFlightEquipment

us-gaap:PaymentsForProceedsFromOtherInvestingActivities

us-gaap:PaymentsToAcquireMarketableSecurities

us-gaap:PaymentsToAcquireOtherProductiveAssets

us-gaap:PaymentsToAcquireOtherPropertyPlantAndEquipment

us-gaap:ProceedsFromIssuanceOfDebt
us-gaap:SubsequentEventType

us-gaap:ProceedsFromIssuanceOfSecuredDebt

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities

us-gaap:ProceedsFromSaleAndMaturityOfMarketableSecurities

us-gaap:ProfessionalAndContractServicesExpense

us-gaap:SellingExpense
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodSharesShareBasedCompensation
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueEmployeeStockPurchasePlan
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation
us-gaap:StatementEquityComponents
us-gaap:StockRepurchasedDuringPeriodShares
us-gaap:StatementEquityComponents
us-gaap:StockRepurchasedDuringPeriodValue
us-gaap:FairValueByMeasurementBasis
alk:NotesPayableFairValueDisclosureBeforePurchasePriceAccountingFairValueAdjustment

us-gaap:AccruedLiabilitiesCurrent

us-gaap:AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax

us-gaap:AdditionalPaidInCapitalCommonStock
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:AssetsFairValueDisclosure
us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:AvailableForSaleSecurities
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:FinancialInstrument
us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByMeasurementFrequency, us-gaap:FinancialInstrument

us-gaap:AvailableForSaleSecuritiesAmortizedCost

us-gaap:BusinessAcquisitionsPurchasePriceAllocationSubsequentYearsRemainingAdjustments

us-gaap:CashCashEquivalentsAndShortTermInvestments
us-gaap:ContractWithCustomerSalesChannel
us-gaap:ContractWithCustomerLiability

us-gaap:ContractWithCustomerLiabilityCurrent

us-gaap:DeferredFinanceCostsNet

us-gaap:DeferredRevenueCurrent

us-gaap:DeferredRevenueNoncurrent

us-gaap:DeferredTaxAndOtherLiabilitiesNoncurrent

us-gaap:DepositsOnFlightEquipment
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeAssets
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeLiabilities
us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency

us-gaap:EmployeeRelatedLiabilitiesCurrent

us-gaap:FlightEquipmentGross
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:LiabilitiesFairValueDisclosure
us-gaap:FairValueByMeasurementFrequency

us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity
us-gaap:DebtInstrument, us-gaap:LineOfCreditFacility

us-gaap:LongTermDebtAndCapitalLeaseObligations

us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent

us-gaap:LongTermDebtPercentageBearingFixedInterestRate

us-gaap:LongTermDebtPercentageBearingVariableInterestRate

us-gaap:MarketableSecuritiesCurrent
us-gaap:FairValueByMeasurementBasis
us-gaap:NotesPayableFairValueDisclosure

us-gaap:OperatingLeaseLiabilityCurrent

us-gaap:OperatingLeaseLiabilityNoncurrent

us-gaap:OtherAssets

us-gaap:PreferredStockParOrStatedValuePerShare

us-gaap:PropertyPlantAndEquipmentOther

us-gaap:RestrictedCashAndCashEquivalentsAtCarryingValue

us-gaap:TreasuryStockShares
us-gaap:OtherCommitments
us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:OtherCommitments
us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:OtherCommitments
us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:OtherCommitments
us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:OtherCommitments
us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:OtherCommitments
us-gaap:UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:OtherCommitments
us-gaap:UnrecordedUnconditionalPurchaseObligationDueInRemainderOfFiscalYear
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:AircraftType
us-gaap:UnrecordedUnconditionalPurchaseObligationMinimumQuantityRequired

Tables

  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
us-gaap:CommonStockValue ▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁███████▅▅▅11111111111111111111111169707070707071373737NANANA
us-gaap:CommonStockParOrStatedValuePerShare ▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁███████0.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.011.01.01.01.01.01.01.0NANA1.0NANANA
us-gaap:CommonStockSharesIssued ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇██▁▁▁▁▁▁▁13113113113113113013013013012912912912912912912812812812812813013113313668697070707071NANA37NANANA
us-gaap:CommonStockSharesOutstanding ▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇██▁▁1221231231231231231231231231231231231231231231231231251261281301311331366869NANANA7071NANANANANANA
us-gaap:CommonStockSharesAuthorized ████████████▃▃▃▃▃▃▃▃▃▃▃▃▁▁▁▁▁▁▁400400400400400400400400400400400400200200200200200200200200200200200200100100100100100100100NANA100NANANA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding 124NA124124123NA123124123NA124124124NA123123125NA128130132NA13613869707171717272363636363636
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic 122NA123123123NA123123123NA123123123NA123123124NA127129131NA13413768697070707071353535353535
us-gaap:EarningsPerShareBasic ▁▅▆▆▃▃▅▅▃▇▆▆▄▄▆▆▅▅▆▅▅▄▅▅▅█▅▄▆▄▄▆▄▆▇▅▃-1.891.48000000000000042.612.120.030.189999999999999951.761.570.033.0400000000000012.152.40.80.92999999999999972.082.111.471.53000000000000022.151.81.131.11999999999999971.471.21.374.131.490.522.30.950.572.150.82.063.411.640.15
us-gaap:EarningsPerShareDiluted ▁▅▆▆▃▃▅▅▃▇▆▆▄▄▆▆▅▅▆▅▅▅▅▅▅█▅▄▆▄▄▆▄▆▇▅▃-1.871.45000000000000022.62.110.030.180000000000000161.751.560.033.042.142.380.790.91000000000000012.072.11.461.50999999999999982.141.791.121.10999999999999991.451.191.354.081.470.512.270.930.562.120.782.013.321.60.15
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ContractWithCustomerSalesChannel alk:CargoandOtherRevenue▃▅██▄▅▆▅▁▁▃▄465260595052555141424748NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ContractWithCustomerSalesChannel alk:MileagePlanRevenue▃█▇▆▃▃▄▄▂▁▁▂261312304290263265267275246240239252NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ContractWithCustomerSalesChannel alk:PassengerRevenue▁▇█▇▃▅▆▆▃▄▆▅148120572211211117161907204319971684179619581945NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService,us-gaap:ContractWithCustomerSalesChannel alk:CargoServices,alk:CargoandOtherRevenue▁▄▇█▄▅▇▆▂▂▅▅242936383032363426273232NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService,us-gaap:ContractWithCustomerSalesChannel alk:MileagePlanServices,alk:PassengerRevenue▃█▇▆▃▄▃▅▂▁▁▂152193186172153160153167139136134143NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService,us-gaap:ContractWithCustomerSalesChannel alk:MileagePlanServicesOther,alk:MileagePlanRevenue▃███▄▁▆▃▂▁▁▃109119118118110105114108107104105109NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService,us-gaap:ContractWithCustomerSalesChannel alk:OtherServices,alk:CargoandOtherRevenue▆▇█▆▅▅▄▃▁▁▁▂222324212020191715151516NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService,us-gaap:ContractWithCustomerSalesChannel alk:PassengerAncillaryServices,alk:PassengerRevenue▁▅█▆▂▃▆▅▁▂▅▄116139157147124129146137117123141134NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService,us-gaap:ContractWithCustomerSalesChannel alk:PassengerTickets,alk:PassengerRevenue▁▆█▇▃▅▇▆▃▄▆▆121317251868179214391618174416931428153716831668NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService,us-gaap:ContractWithCustomerSalesChannel us-gaap:CargoAndFreight,alk:CargoandOtherRevenue▃▅██▄▅▆▅▁▁▃▄465260595052555141424748NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService,us-gaap:ContractWithCustomerSalesChannel us-gaap:Passenger,alk:MileagePlanRevenue▃█▇▆▃▄▃▅▂▁▁▂152193186172153160153167139136134143NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService,us-gaap:ContractWithCustomerSalesChannel us-gaap:Passenger,alk:PassengerRevenue▁▇█▇▃▅▆▆▃▄▆▅148120572211211117161907204319971684179619581945NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService alk:MileagePlanServicesOther109NA118118110NA114108107NA105109NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService us-gaap:CargoAndFreight46NA605950NA555141NA4748NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService us-gaap:Passenger1481NA221121111716NA204319971684NA19581945NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService,us-gaap:StatementBusinessSegments alk:CapacityPurchaseAgreements,alk:Horizon105NA112112116NA128137110NA112108NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService,us-gaap:StatementBusinessSegments alk:MileagePlanServicesOther,alk:AirGroupAdjusted109NA118118110NA114108107NA105109NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService,us-gaap:StatementBusinessSegments alk:MileagePlanServicesOther,alk:AlaskaMainline98NA107105100NA1049998NA97101NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService,us-gaap:StatementBusinessSegments alk:MileagePlanServicesOther,alk:AlaskaRegional11NA111310NA1099NA88NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:CargoAndFreight,alk:AirGroupAdjusted46NA605950NA555141NA4748NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:CargoAndFreight,alk:AlaskaMainline44NA585748NA534940NA4645NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:CargoAndFreight,alk:AlaskaRegional0NA101NA010NA02NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:CargoAndFreight,alk:Horizon0NA001NA211NA11NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:CargoAndFreight,us-gaap:IntersegmentElimination2NA120NA000NA00NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:Passenger,alk:AirGroupAdjusted1481NA221121111716NA204319971684NA19581945NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:Passenger,alk:AlaskaMainline1234NA185017671422NA172717111441NA16771677NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService,us-gaap:StatementBusinessSegments us-gaap:Passenger,alk:AlaskaRegional247NA361344294NA316286243NA281268NANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:Revenues ▇████████▁██▇▂▇▇▇▆▆▆▆▆▆▆▆▆▆▆▆▆▇▇▇▇▇▇▇163622282389228818762064221221561832-5952211021021749-440715661494134700000000000001039119811109651068976829
 us-gaap:Revenues us-gaap:StatementBusinessSegments alk:AirGroupAdjusted▇████████▁██▇▂▇▇▇▆▆▆▆▆▆▆▆▆▆▆▆▆▇▇▇▇163622282389228818762064221221561832-5952211021021749-44071566149413470000000000000103911981110965NANANA
 us-gaap:Revenues us-gaap:StatementBusinessSegments alk:AlaskaMainline▇████████▁███▂▇▇▇▆▆▆▆▆▆▆▆▆▆▆▆▆▇▇▇▇137618672015192915701741188418591579-5147182018231517-36611293124611220000000000000849981912785NANANA
 us-gaap:Revenues us-gaap:StatementBusinessSegments alk:AlaskaRegional▇███████▇▁▇▇▇▁▇▇▇▆▆▆▆▆▆▆▆▆▆▆▆▆▇▇▇▇258359373357305323326296252-802289278230-7422712472240000000000000187214195177NANANA
us-gaap:CostsAndExpenses 1957NANANA1851515758NA556166NANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:CostsAndExpenses us-gaap:StatementBusinessSegments alk:AirGroupAdjusted1785NANANA1829NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:CostsAndExpenses us-gaap:StatementBusinessSegments alk:AlaskaMainline1472NANANA1510NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:CostsAndExpenses us-gaap:StatementBusinessSegments alk:AlaskaRegional331NANANA340NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OperatingIncomeLoss ▁▆▇▇▄▄▆▆▄▅██▅▆▇▇▆▆▇▇▆▆▆▆▅█▅▄▆▅▄▅▄▅▆▅▄-32125242236425462972712916243949316624140041829025543337223824231626314147017464269115721435713321610925
us-gaap:OtherNonoperatingIncomeExpense ▆▃▄▂▂▄▂▄▁▄▄▄▄▅▄▄▅▄▄▅▄▄▅▆█▃▄▅▅▅▅▅▅▄▅▅▄5-6-3-7-10-3-7-1-1200-1010-31001002513-502211110110
us-gaap:NonoperatingIncomeExpense ▇▄▄▃▂▄▃▃▁▃▃▃▃▄▆▆▆▇▇▇▆▆▆▆█▄▅▅▅▄▅▂▄▃▂▃▃4-9-6-13-19-10-13-12-23-13-12-14-14-10222444200211-7-5-5-3-6-5-17-10-13-18-15-15
 us-gaap:NonoperatingIncomeExpense us-gaap:StatementBusinessSegments alk:AirGroupAdjusted▇▄▄▃▂▄▃▃▁▃▃▃▃▄▆▆▆▇▇▇▆▆▆▆█▄▅▅▅▄▅▂▄▃4-9-6-13-19-10-13-12-23-13-12-14-14-10222444200211-7-5-5-3-6-5-17-10-13NANANA
 us-gaap:NonoperatingIncomeExpense us-gaap:StatementBusinessSegments alk:AlaskaMainline▇▃▄▃▂▄▃▃▁▂▂▂▁▂▆▆▄▅▆▆▆▅▅▆█▅▄▄▄▄▄▁▃▂11-40-6-11-3-6-4-12-9-7-11-12-855145553451541-10-3-2-13-6-8NANANA
us-gaap:IncomeTaxExpenseBenefit ▃▆▆▆▅▅▆▆▅▁██▆▇▇█▇▆█▇▆▆▇▇▆█▆▅▇▆▅▆▅▆▆▅▅-8562948921367662-22416118353117146160108681631429194118100581746522102412547184675354
us-gaap:IncomeTaxesPaidNet ▃▄▃▃▃▃▃▃▃▄▆▃▃▇▇█▃▅▇█▁▇▆▅▃0292000000481151221381391691387154173-6514192876NANA6NANA-2NANA0NANA0
us-gaap:ComprehensiveIncomeNetOfTax ▁▆█▇▄▄▇▆▄█▇█▅▅▇▇▆▆▇▇▆▄▆▆▅█▅▅▆▅▅▅▄▅-2491373232731932241986283270301105932592671931912752351541619816896299109441706948813277NANANA
us-gaap:NetIncomeLoss ▁▆▇▇▄▄▆▆▄█▇▇▅▅▇▇▆▆▇▆▅▅▆▆▅▇▅▄▆▄▄▅▄▅▅▄▄-23218132226242321719343732662969911425626018419127423414914819816594289104371636740772874122585
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
us-gaap:Assets ████▇▆▆▆▆▆▆▆▅▅▄▃▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁13363129931298312951126401091210893110551084810740107391072010302996286997035682965336564648064106181623663146061586258525644543654235382526052335111NANANA
 us-gaap:Assets us-gaap:StatementBusinessSegments alk:AlaskaAirlines█████▇▆▆▆▇▆▆▆▆▄▃▃▃▂▂▂▂▂▂▂▁▁▁▁▁▁1967719207191291905018698168531472515334150881666316382162721573515260109499101863081297922756771536772665564736124573155825346508249944894NANANANANANA
us-gaap:LiabilitiesAndStockholdersEquity ████▇▆▆▆▆▆▆▆▅▅▄▂▂▂▂▂▂▁▂▂▁▁▁▁13363129931298312951126401091210893110551084810740107391072010302996286997035682965336564648064106181623663146061586258525644NA54235382526052335111NANANA
us-gaap:StockholdersEquity ▇██▇▇▇▇▆▆▇▆▅▅▅▄▄▃▃▃▃▃▃▃▃▃▂▁▁4015433142523973374637513791359334393721349132643014293128642627245524112365221921662127222922002095180215431462NA12831218126412061170NANANA
 us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:RetainedEarnings▆█▇▅▃▃▄▂▁▃4856513349964717449845344550437342194454NANANA3568NANANA2890NANANA2144NANANANANANANANANA746669640NANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
us-gaap:AssetsCurrent ▄▂▃▃▂▁▂▃▃▃▃▄▃▂█▂▂▁▁▁▁▁▂▂▂▂▂▂2572203722022218200117872056221621142146221424252213205036002003192316631715165417761756179920201934193519861839NA16981656172616751596NANANA
us-gaap:CashAndCashEquivalentsAtCarryingValue ▄▂▂▂▂▁▂▁▂▂▁▂▂▂█▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁8112212372442151051741021771941441981833281818817873884551107342290415795273548676760129108117
us-gaap:ReceivablesNetCurrent ▄▅▇▇▆▇██▆▆▅▆▅▅▃▄▃▃▂▂▂▄▂▂▃▂▂▂▂▂▂▁▁▁279323377389358366422411350341301326321302232254235212205194187259178203212182195188185169168148167161NANANA
 us-gaap:ReceivablesNetCurrent us-gaap:ContractWithCustomerSalesChannel alk:MileagePlanRevenue▁▄▄█▇▇▅▄88105103122115119106103NA101NANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:InventoryNet ▇█▆▄▄▅▄▄▆▄▄▃▂▂▁▁▁▃▃▄▃▄▆▅▄▅▅▅▃▂▁▁▃▁68726355586057576257575250474445455152585258646158605961524745445245NANANA
us-gaap:PrepaidExpenseAndOtherAssetsCurrent ▃▄▆▆▆▄███▅▄▄▅▄▃▃▁▁▁▂▃▃▃▅▄▃▄▅▄▄▃100121143147149125180180174127116125132121989779727487102105100134124105114132116121100NANANANANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
us-gaap:PropertyPlantAndEquipmentGross ████▇▇▇▇▇▆▆▆▆▅▄▄▄▄▃▃▃▃▂▂▂▁▁▁101611038810227100519862100239662958494149275930890618817859579087743752974167268716568816616649462916068582657155564NA52885230499648534763NANANA
us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment ▇██▇▇▇▇▇▆▆▇▆▆▆▆▅▅▅▅▄▄▄▄▃▃▃▃▂▂▂▂▁▁▁3307348633933307323332423167309130112991307830593008292928772784269926142534246023842317225021892138203419901925180517401727164616031561NANANA
us-gaap:PropertyPlantAndEquipmentNet ████▇█▇▇▇▇▇▆▆▅▄▄▄▃▃▃▃▂▂▂▂▁▁▁6854690268346744662967816495649364036284623060025809566650314959483048024734470544974299424441023930379237253639NA35473503335032493202NANANA
us-gaap:Goodwill ██████████▁▆▇▁19431943194319431943194319431943194319431934194019421934NANANA0NANANANANANANANANANANANANANANANANANANA
us-gaap:IntangibleAssetsNetExcludingGoodwill ▁▄▄▄▅▅▅▅▆▆▆▇▇█110122123125127127128130132133135137139143NANANA0NANANANANANANANANANANANANANANANANANANA
us-gaap:OtherAssetsNoncurrent █▇▆▆▆▇▇▇▇▆▆▅▅▄▁▁▁▁▂▃▃▃▅▅▅▃▃▃▃▃▃▃▆▅30027823422522527427127325623422621619916968737668115121137126193192197126128143129138148136223211NANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
us-gaap:LiabilitiesCurrent █▆▇▇▇▅▅▆▆▅▅▆▅▄▃▃▃▂▂▂▂▁▂▂▂▁▂▁3730320133463534338629422888303629922700276529742835253521232061206918061854192718801671176718641755165017561598NA16641673151816281484NANANA
us-gaap:AccountsPayableCurrent ▅▇▅██▆▅▅▄▅▄▄▄▃▂▃▁▁▁▁▁▁▂▂▂▁▂▄▂▅▆▃▂▁119146120156157132114115102120979595927178636361565762687175607110170110129887159NANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
us-gaap:LiabilitiesNoncurrent █▇▇▇▇▄▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▂▂4415419739413906384426022530242823552338211620131922185118511838177417451752170517141697153015051490162817391744NA15191453129812441181NANANA
us-gaap:LongTermDebt ▆▄▄▅▅▅▅▆▆▇▇███▆▁▁▁▁▁▁▂▂▂▂▂▂▂▂▃▃▃▃22621499170918261964210320292312244925692701280628632964213662664768671074576880382585983489392494610661140124713921408NANANANA
 us-gaap:LongTermDebt us-gaap:DebtInstrument alk:Fixedratenotespayableduethrough2029▁▂█457475569NANA642NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LongTermDebt us-gaap:DebtInstrument alk:Variableratenotespayableduethrough2029Member█▁▂181610321150NANA1473NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LongTermDebt us-gaap:LongtermDebtType alk:VariableRatedebtwithinterestrateswap694NA745NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent ██▆▇▇▇▆▆▆▆▄▄▄▄▃▃▃▃▃▃▃▃▁▁▁▆▆▆▆▆▆▄▅▅577571467522513503470464458453323336334331272271270270249247247246124123122461470479447452458336361364NANANA
us-gaap:OtherLiabilitiesNoncurrent ▄▄▃▃▃▇█▇▇████▇▆▆▆▆▆▆▆▅▅▅▅▅▅▆▃▃▃▂▂▁253232213197210418428417423451429427438417355366359362341339332327312315309318318332213204184170148108NANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
us-gaap:StockholdersEquity ▇██▇▇▇▇▆▆▇▆▅▅▅▄▄▃▃▃▃▃▃▃▃▃▂▁▁4015433142523973374637513791359334393721349132643014293128642627245524112365221921662127222922002095180215431462NA12831218126412061170NANANA
 us-gaap:StockholdersEquity us-gaap:StatementEquityComponents us-gaap:RetainedEarnings▆█▇▅▃▃▄▂▁▃4856513349964717449845344550437342194454NANANA3568NANANA2890NANANA2144NANANANANANANANANA746669640NANANA
us-gaap:CommonStockValue ▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁███████▅▅▅11111111111111111111111169707070707071373737NANANA
us-gaap:RetainedEarningsAccumulatedDeficit ███▇▇▇▇▇▇▇▆▆▆▆▅▅▅▅▄▄▄▃▃▃▃▂▂▂▂▁▁▁▁▁48565133499647174498453445504373421944544117388836293568348832663039289027242474226621442012183116841542126811641082918851746669640NANANA
us-gaap:TreasuryStockValue ██▇▇▇▇▇▇▇▆▆▆▆▆▆▆▅▄▂▁▁▁▁▁▁▁67464362159358156855654453151849446644344344444437725012787455121NANA0001077972NANANA
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax ▁▁▂▂▂▂▂▂▂▃▅▅▅▅▆▅▅▅▅▅▅▅███▃▂▂▄▃▃▆▆▆-482-465-421-422-433-448-428-435-440-380-289-294-299-305-284-287-294-303-303-304-305-310-178-178-181-414-424-429-373-380-382-256-260-263NANANA
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities ▁▅▅▇▆▃▄▆▄▃▄█▆▃▄▅▇▅▅▅▇▂▄▅▄33341348565468209260420306233273614470180307374525355340375514138257393242NANA212NANA183NANA118NANA54
us-gaap:NetCashProvidedByUsedInInvestingActivities ▇▇▇▆▇▇█▇▇█▇▆▆▁▇▇▆▇▇▇▆█▇▆▇-127-83-178-344-186-298135-304-16410-171-483-488-1981-51-254-336-203-133-173-42177-36-418-164NANA-151NANA-173NANA-33NANA-47
us-gaap:NetCashProvidedByUsedInFinancingActivities ▅▁▂▁▂▂▁▁▂▁▂▂▂▃█▂▂▂▂▁▂▂▁▂▂684-275-175-192-17119-319-191-156-193-156-116-1273111481-117-184-167-164-208-149-142-209-43-68NANA-88NANA-63NANA-114NANA-53
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities ▁▅▅▇▆▃▄▆▄▃▄█▆▃▄▅▇▅▅▅▇▂▄▅▄33341348565468209260420306233273614470180307374525355340375514138257393242NANA212NANA183NANA118NANA54
us-gaap:NetIncomeLoss ▁▆▇▇▄▄▆▆▄█▇▇▅▅▇▇▆▆▇▆▅▅▆▆▅▇▅▄▆▄▄▅▄▅▅▄▄-23218132226242321719343732662969911425626018419127423414914819816594289104371636740772874122585
us-gaap:DepreciationDepletionAndAmortization ██████▇▇▆▇▆▆▆▄▇▆▅▅▄▄▄▄▄▃▃▂▃▃▂▂▂▂▂▂▁▁▁108106106105106108999794979590908210192888481797676757370676869656563626160575856
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInInvestingActivities ▇▇▇▆▇▇█▇▇█▇▆▆▁▇▇▆▇▇▇▆█▇▆▇-127-83-178-344-186-298135-304-16410-171-483-488-1981-51-254-336-203-133-173-42177-36-418-164NANA-151NANA-173NANA-33NANA-47
us-gaap:PaymentsToAcquirePropertyPlantAndEquipment ▂▃▃▄▁█▂▃▄▃▆▆▄▃▃▄▂▃▁▅▅▂▄▅▁11916919421811540613118823518532929621616916922111916310928027913520925793NANA103NANA98NANA149NANA25
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInFinancingActivities ▅▁▂▁▂▂▁▁▂▁▂▂▂▃█▂▂▂▂▁▂▂▁▂▂684-275-175-192-17119-319-191-156-193-156-116-1273111481-117-184-167-164-208-149-142-209-43-68NANA-88NANA-63NANA-114NANA-53
us-gaap:RepaymentsOfLongTermDebt ▂▆▅▃█▆▆▃▃▃▃▂▃▄▁▁▁▁▁▁▁▁▁▁▁60306220139393263286138120132106581011563621362335233522332737NANA88NANA59NANA89NANA39
us-gaap:PaymentsOfDividends █████▇▆▇▆▆▆▆▆▅▅▅▅▃▃▃▃▁▁▁▁45444343434039403937373737343434342426262617171717NA00NANANANANANANANANA
us-gaap:PaymentsOfDividends █████▇▆▇▆▆▆▆▆▅▅▅▅▃▃▃▃▁▁▁▁45444343434039403937373737343434342426262617171717NA00NANANANANANANANANA
us-gaap:PaymentsForRepurchaseOfCommonStock ▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▄▇▆▆█▅▆█▃▂312228121313121312252822000661271241191601021061595330NANA19NANA8NANA26NANA10
  2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
us-gaap:RepaymentsOfLongTermDebt ▂▆▅▃█▆▆▃▃▃▃▂▃▄▁▁▁▁▁▁▁▁▁▁▁60306220139393263286138120132106581011563621362335233522332737NANA88NANA59NANA89NANA39

Common Stock Value

us-gaap:CommonStockValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value111111111111111111111111696970707070707071373737373735
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.01.11.21.21.21.21.31.31.31.30.70.70.70.70.70.7

Common Stock Par Or Stated Value Per Share

us-gaap:CommonStockParOrStatedValuePerShare



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-03-312010-12-312009-12-31
Value0.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.011.01.01.01.01.01.01.01.01.01.01.01.01.0
Percentage of CommonStockParOrStatedValuePerShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Common Stock Shares Issued

us-gaap:CommonStockSharesIssued



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-03-312010-12-312009-12-31
Value13113113113113113013013013012912912912912912912812812812812813013113313668686970707070707137373735
Percentage of CommonStockSharesIssued100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Common Stock Shares Outstanding

us-gaap:CommonStockSharesOutstanding



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-312012-06-302012-03-312011-12-31
Value12212312312312312312312312312312312312312312312312312512612813013113313668686970707135
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value012300012300012312312513168703535363535353638
Percentage of CommonStockSharesOutstanding0.0100.00.00.00.0100.00.00.00.0100.0100.0100.0100.0100.0100.099.90.00.00.00.00.00.00.0

Common Stock Shares Authorized

us-gaap:CommonStockSharesAuthorized



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-03-312010-12-312009-12-31
Value400400400400400400400400400400400400200200200200200200200200200200200200100100100100100100100100100100100100100
Percentage of CommonStockSharesAuthorized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value12412412412312312412312412412412312312512813013213613869707171717272363636363636
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value12212312312312312312312312312312312312412712913113413768697070707071353535353535
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value-1.891.48000000000000042.612.120.030.189999999999999951.761.570.033.0400000000000012.152.40.80.92999999999999972.082.111.471.53000000000000022.151.81.131.11999999999999971.471.21.374.131.490.522.30.950.572.150.82.063.411.640.15
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value-1.871.45000000000000022.62.110.030.180000000000000161.751.560.033.042.142.380.790.91000000000000012.072.11.461.50999999999999982.141.791.121.10999999999999991.451.191.354.081.470.512.270.930.562.120.782.013.321.60.15
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Revenue From Contract With Customer Excluding Assessed Tax

us-gaap:ContractWithCustomerSalesChannel

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax

alk:CargoandOtherRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value465260595052555141424748
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues2.80.02.52.62.70.02.52.42.20.02.22.3
Percentage of Revenues alk:CargoandOtherRevenue0.00.00.00.00.00.00.00.00.00.00.00.0

alk:MileagePlanRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value261312304290263265267275246240239252
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax567.4600.0506.7491.5526.0509.6485.5539.2600.0571.4508.5525.0
Percentage of Revenues16.00.012.712.714.00.012.112.813.40.011.312.0
Percentage of Revenues alk:MileagePlanRevenue0.00.00.00.00.00.00.00.00.00.00.00.0

alk:PassengerRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value148120572211211117161907204319971684179619581945
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3219.63955.83685.03578.03432.03667.33714.53915.74107.34276.24166.04052.1
Percentage of Revenues90.50.092.592.391.50.092.492.691.90.092.892.5
Percentage of Revenues alk:PassengerRevenue0.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ProductOrService, us-gaap:ContractWithCustomerSalesChannel

alk:CargoServices, alk:CargoandOtherRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value242936383032363426273232
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax52.255.860.064.460.061.565.566.763.464.368.166.7
Percentage of Revenues1.50.01.51.71.60.01.61.61.40.01.51.5
Percentage of Revenues alk:CargoServices alk:CargoandOtherRevenue0.00.00.00.00.00.00.00.00.00.00.00.0

alk:MileagePlanServices, alk:PassengerRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value152193186172153160153167139136134143
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax330.4371.2310.0291.5306.0307.7278.2327.5339.0323.8285.1297.9
Percentage of Revenues9.30.07.87.58.20.06.97.77.60.06.46.8
Percentage of Revenues alk:MileagePlanServices alk:PassengerRevenue0.00.00.00.00.00.00.00.00.00.00.00.0

alk:MileagePlanServicesOther, alk:MileagePlanRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value109119118118110105114108107104105109
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax237.0228.8196.7200.0220.0201.9207.3211.8261.0247.6223.4227.1
Percentage of Revenues6.70.04.95.25.90.05.25.05.80.05.05.2
Percentage of Revenues alk:MileagePlanServicesOther alk:MileagePlanRevenue0.00.00.00.00.00.00.00.00.00.00.00.0

alk:OtherServices, alk:CargoandOtherRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value222324212020191715151516
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax47.844.240.035.640.038.534.533.336.635.731.933.3
Percentage of Revenues1.30.01.00.91.10.00.90.80.80.00.70.8
Percentage of Revenues alk:OtherServices alk:CargoandOtherRevenue0.00.00.00.00.00.00.00.00.00.00.00.0

alk:PassengerAncillaryServices, alk:PassengerRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value116139157147124129146137117123141134
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax252.2267.3261.7249.2248.0248.1265.5268.6285.4292.9300.0279.2
Percentage of Revenues7.10.06.66.46.60.06.66.46.40.06.76.4
Percentage of Revenues alk:PassengerAncillaryServices alk:PassengerRevenue0.00.00.00.00.00.00.00.00.00.00.00.0

alk:PassengerTickets, alk:PassengerRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value121317251868179214391618174416931428153716831668
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax2637.03317.33113.33037.32878.03111.53170.93319.63482.93659.53580.93475.0
Percentage of Revenues74.10.078.278.376.70.078.878.577.90.079.879.4
Percentage of Revenues alk:PassengerTickets alk:PassengerRevenue0.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CargoAndFreight, alk:CargoandOtherRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value465260595052555141424748
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues2.80.02.52.62.70.02.52.42.20.02.22.3
Percentage of Revenues us-gaap:CargoAndFreight alk:CargoandOtherRevenue0.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Passenger, alk:MileagePlanRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value152193186172153160153167139136134143
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax330.4371.2310.0291.5306.0307.7278.2327.5339.0323.8285.1297.9
Percentage of Revenues9.30.07.87.58.20.06.97.77.60.06.46.8
Percentage of Revenues us-gaap:Passenger alk:MileagePlanRevenue0.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:Passenger, alk:PassengerRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value148120572211211117161907204319971684179619581945
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax3219.63955.83685.03578.03432.03667.33714.53915.74107.34276.24166.04052.1
Percentage of Revenues90.50.092.592.391.50.092.492.691.90.092.892.5
Percentage of Revenues us-gaap:Passenger alk:PassengerRevenue0.00.00.00.00.00.00.00.00.00.00.00.0

Revenue From Contract With Customer Including Assessed Tax

us-gaap:ProductOrService

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax

alk:MileagePlanServicesOther



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value109118118110114108107105109
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues6.74.95.25.95.25.05.85.05.2
Percentage of Revenues alk:MileagePlanServicesOther0.00.00.00.00.00.00.00.00.0

us-gaap:CargoAndFreight



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value466059505551414748
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax42.250.850.045.548.247.238.344.844.0
Percentage of Revenues2.82.52.62.72.52.42.22.22.3
Percentage of Revenues us-gaap:CargoAndFreight0.00.00.00.00.00.00.00.00.0

us-gaap:Passenger



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value148122112111171620431997168419581945
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1358.71873.71789.01560.01792.11849.11573.81864.81784.4
Percentage of Revenues90.592.592.391.592.492.691.992.892.5
Percentage of Revenues us-gaap:Passenger0.00.00.00.00.00.00.00.00.0

us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

alk:CapacityPurchaseAgreements, alk:Horizon



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value105112112116128137110112108
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax96.394.994.9105.5112.3126.9102.8106.799.1
Percentage of Revenues6.44.74.96.25.86.46.05.35.1
Percentage of Revenues alk:CapacityPurchaseAgreements alk:Horizon0.00.00.00.00.00.00.00.00.0

alk:CapacityPurchaseAgreements, us-gaap:IntersegmentElimination



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value-105-112-112-116-128-137-110-112-108
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-96.3-94.9-94.9-105.5-112.3-126.9-102.8-106.7-99.1
Percentage of Revenues-6.4-4.7-4.9-6.2-5.8-6.4-6.0-5.3-5.1
Percentage of Revenues alk:CapacityPurchaseAgreements us-gaap:IntersegmentElimination0.00.00.00.00.00.00.00.00.0

alk:MileagePlanServicesOther, alk:AirGroupAdjusted



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value109118118110114108107105109
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues6.74.95.25.95.25.05.85.05.2
Percentage of Revenues alk:MileagePlanServicesOther alk:AirGroupAdjusted0.00.00.00.00.00.00.00.00.0

alk:MileagePlanServicesOther, alk:AlaskaMainline



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value98107105100104999897101
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax89.990.789.090.991.291.791.692.492.7
Percentage of Revenues6.04.54.65.34.74.65.34.64.8
Percentage of Revenues alk:MileagePlanServicesOther alk:AlaskaMainline0.00.00.00.00.00.00.00.00.0

alk:MileagePlanServicesOther, alk:AlaskaRegional



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value11111310109988
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax10.19.311.09.18.88.38.47.67.3
Percentage of Revenues0.70.50.60.50.50.40.50.40.4
Percentage of Revenues alk:MileagePlanServicesOther alk:AlaskaRegional0.00.00.00.00.00.00.00.00.0

us-gaap:CargoAndFreight, alk:AirGroupAdjusted



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value466059505551414748
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax42.250.850.045.548.247.238.344.844.0
Percentage of Revenues2.82.52.62.72.52.42.22.22.3
Percentage of Revenues us-gaap:CargoAndFreight alk:AirGroupAdjusted0.00.00.00.00.00.00.00.00.0

us-gaap:CargoAndFreight, alk:AlaskaMainline



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value445857485349404645
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax40.449.248.343.646.545.437.443.841.3
Percentage of Revenues2.72.42.52.62.42.32.22.22.1
Percentage of Revenues us-gaap:CargoAndFreight alk:AlaskaMainline0.00.00.00.00.00.00.00.00.0

us-gaap:CargoAndFreight, alk:AlaskaRegional



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value010101002
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.80.00.90.00.90.00.01.8
Percentage of Revenues0.00.00.00.10.00.00.00.00.1
Percentage of Revenues us-gaap:CargoAndFreight alk:AlaskaRegional0.00.00.00.00.00.00.00.00.0

us-gaap:CargoAndFreight, alk:Horizon



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value000121111
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.00.00.91.80.90.91.00.9
Percentage of Revenues0.00.00.00.10.10.00.10.00.0
Percentage of Revenues us-gaap:CargoAndFreight alk:Horizon0.00.00.00.00.00.00.00.00.0

us-gaap:CargoAndFreight, us-gaap:IntersegmentElimination



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value212000000
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.80.81.70.00.00.00.00.00.0
Percentage of Revenues0.10.00.10.00.00.00.00.00.0
Percentage of Revenues us-gaap:CargoAndFreight us-gaap:IntersegmentElimination0.00.00.00.00.00.00.00.00.0

us-gaap:Passenger, alk:AirGroupAdjusted



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value148122112111171620431997168419581945
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1358.71873.71789.01560.01792.11849.11573.81864.81784.4
Percentage of Revenues90.592.592.391.592.492.691.992.892.5
Percentage of Revenues us-gaap:Passenger alk:AirGroupAdjusted0.00.00.00.00.00.00.00.00.0

us-gaap:Passenger, alk:AlaskaMainline



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value123418501767142217271711144116771677
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1132.11567.81497.51292.71514.91584.31346.71597.11538.5
Percentage of Revenues75.477.477.275.878.179.478.779.579.8
Percentage of Revenues us-gaap:Passenger alk:AlaskaMainline0.00.00.00.00.00.00.00.00.0

us-gaap:Passenger, alk:AlaskaRegional



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value247361344294316286243281268
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax226.6305.9291.5267.3277.2264.8227.1267.6245.9
Percentage of Revenues15.115.115.015.714.313.313.313.312.7
Percentage of Revenues us-gaap:Passenger alk:AlaskaRegional0.00.00.00.00.00.00.00.00.0

Revenues

us-gaap:Revenues



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value163622282389228818762064221221561832-5952211021021749-440715661494134700000000000001039119811109651068976829
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.00.00.00.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.00.00.00.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments

alk:AirGroupAdjusted



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value163622282389228818762064221221561832-5952211021021749-44071566149413470000000000000103911981110965
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.00.00.00.0100.0100.0100.0100.0
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.00.00.00.0100.0100.0100.0100.0
Percentage of Revenues alk:AirGroupAdjusted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.00.00.00.0100.0100.0100.0100.0

alk:AlaskaMainline



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value137618672015192915701741188418591579-5147182018231517-36611293124611220000000000000849981912785
Percentage of Revenues84.183.884.384.383.784.485.286.286.286.586.386.786.783.182.683.483.30.00.00.00.00.00.00.00.00.00.00.00.00.081.881.982.281.4
Percentage of Revenues84.183.884.384.383.784.485.286.286.286.586.386.786.783.182.683.483.30.00.00.00.00.00.00.00.00.00.00.00.00.081.881.982.281.4
Percentage of Revenues alk:AlaskaMainline100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.00.00.00.0100.0100.0100.0100.0

alk:AlaskaRegional



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value258359373357305323326296252-802289278230-7422712472240000000000000187214195177
Percentage of Revenues15.816.115.615.616.315.614.713.713.813.513.713.213.216.817.316.516.60.00.00.00.00.00.00.00.00.00.00.00.00.018.117.917.618.4
Percentage of Revenues15.816.115.615.616.315.614.713.713.813.513.713.213.216.817.316.516.60.00.00.00.00.00.00.00.00.00.00.00.00.018.117.917.618.4
Percentage of Revenues alk:AlaskaRegional100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.00.00.00.0100.0100.0100.0100.0

alk:Horizon



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-30
Value1051101121121171331301381111061131099899110111104105105999994998791889194968988939597180171
Percentage of Revenues6.44.94.74.96.26.45.96.46.1-1.85.45.25.6-2.27.07.47.70.00.00.00.00.00.00.00.00.00.00.00.00.08.67.88.610.016.917.5
Percentage of Revenues6.44.94.74.96.26.45.96.46.1-1.85.45.25.6-2.27.07.47.70.00.00.00.00.00.00.00.00.00.00.00.00.08.67.88.610.016.917.5
Percentage of Revenues alk:Horizon100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-30
Value-103-108-111-110-116-133-128-137-110-109-112-108-97-102-109-110-103-105-105-99-99-94-99-87-91-88-91-94-96-89-87-91-93-94-69-67
Percentage of Revenues-6.3-4.8-4.6-4.8-6.2-6.4-5.8-6.4-6.01.8-5.3-5.1-5.52.3-7.0-7.4-7.60.00.00.00.00.00.00.00.00.00.00.00.00.0-8.4-7.6-8.4-9.8-6.5-6.9
Percentage of Revenues-6.3-4.8-4.6-4.8-6.2-6.4-5.8-6.4-6.01.8-5.3-5.1-5.52.3-7.0-7.4-7.60.00.00.00.00.00.00.00.00.00.00.00.00.0-8.4-7.6-8.4-9.8-6.5-6.9
Percentage of Revenues us-gaap:IntersegmentElimination100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Sales Revenue Net

Operating Expenses

Costs And Expenses

us-gaap:CostsAndExpenses



Period End2020-03-312019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-30
Value19571851515758556166
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues119.698.72.52.62.7-0.92.93.1

us-gaap:StatementBusinessSegments

alk:AirGroupAdjusted



Period End2020-03-312019-03-31
Value17851829
Percentage of CostsAndExpenses91.298.8
Percentage of Revenues109.197.5
Percentage of Revenues alk:AirGroupAdjusted109.197.5

alk:AlaskaMainline



Period End2020-03-312019-03-31
Value14721510
Percentage of CostsAndExpenses75.281.6
Percentage of Revenues90.080.5
Percentage of Revenues alk:AlaskaMainline107.096.2

alk:AlaskaRegional



Period End2020-03-312019-03-31
Value331340
Percentage of CostsAndExpenses16.918.4
Percentage of Revenues20.218.1
Percentage of Revenues alk:AlaskaRegional128.3111.5

alk:Horizon



Period End2020-03-312019-03-31
Value9297
Percentage of CostsAndExpenses4.75.2
Percentage of Revenues5.65.2
Percentage of Revenues alk:Horizon87.682.9

alk:SpecialRevenueandCharges



Period End2020-03-312019-03-31
Value17222
Percentage of CostsAndExpenses8.81.2
Percentage of Revenues10.51.2
Percentage of Revenues alk:SpecialRevenueandCharges0.00.0

us-gaap:IntersegmentElimination



Period End2020-03-312019-03-31
Value-110-118
Percentage of CostsAndExpenses-5.6-6.4
Percentage of Revenues-6.7-6.3
Percentage of Revenues us-gaap:IntersegmentElimination106.8101.7

Operating Income Loss

us-gaap:OperatingIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value-32125242236425462972712916243949316624140041829025543337223824231626314147017464269115721435713321610925
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-19.611.317.715.91.32.213.412.61.6-2.720.823.59.5-5.525.528.021.50.00.00.00.00.00.00.00.00.00.00.00.00.07.012.05.213.920.311.23.1

Interest Expense

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value5-6-3-7-10-3-7-1-1200-1010-31001002513-502211110110
Percentage of OtherNonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.00.0100.00.0100.0100.00.00.0100.00.00.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.3-0.3-0.1-0.3-0.5-0.1-0.3-0.0-0.7-0.00.0-0.00.0-0.00.0-0.20.10.00.00.00.00.00.00.00.00.00.00.00.00.00.10.10.10.10.20.10.1

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

Nonoperating Income Expense

us-gaap:NonoperatingIncomeExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value4-9-6-13-19-10-13-12-23-13-12-14-14-10222444200211-7-5-5-3-6-5-17-10-13-18-15-15
Percentage of NonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.2-0.4-0.3-0.6-1.0-0.5-0.6-0.6-1.30.2-0.6-0.7-0.80.20.10.10.10.00.00.00.00.00.00.00.00.00.00.00.00.0-0.6-1.5-1.0-1.4-1.8-1.6-1.9

us-gaap:StatementBusinessSegments

alk:AirGroupAdjusted



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value4-9-6-13-19-10-13-12-23-13-12-14-14-10222444200211-7-5-5-3-6-5-17-10-13
Percentage of NonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues0.2-0.4-0.3-0.6-1.0-0.5-0.6-0.6-1.30.2-0.6-0.7-0.80.20.10.10.10.00.00.00.00.00.00.00.00.00.00.00.00.0-0.6-1.5-1.0-1.4
Percentage of Revenues alk:AirGroupAdjusted0.2-0.4-0.3-0.6-1.0-0.5-0.6-0.6-1.30.2-0.6-0.7-0.80.20.10.10.10.00.00.00.00.00.00.00.00.00.00.00.00.0-0.6-1.5-1.0-1.4

alk:AlaskaMainline



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value11-40-6-11-3-6-4-12-9-7-11-12-855145553451541-10-3-2-13-6-8
Percentage of NonoperatingIncomeExpense275.044.4-0.046.257.930.046.233.352.269.258.378.685.780.0250.0250.050.0100.0125.0125.0250.00.00.0250.0136.4-57.1-20.020.02.647.841.477.163.967.9
Percentage of Revenues0.7-0.20.0-0.3-0.6-0.1-0.3-0.2-0.70.2-0.3-0.5-0.70.20.30.30.10.00.00.00.00.00.00.00.00.00.00.00.00.0-0.2-1.2-0.6-0.9
Percentage of Revenues alk:AlaskaMainline0.8-0.20.0-0.3-0.7-0.2-0.3-0.2-0.80.2-0.4-0.6-0.80.20.40.40.10.00.00.00.00.00.00.00.00.00.00.00.00.0-0.3-1.4-0.8-1.1

alk:AlaskaRegional



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value000000-2-2-7000000000000000-1-8-10000000
Percentage of NonoperatingIncomeExpense0.0-0.0-0.0-0.0-0.0-0.015.416.730.4-0.0-0.0-0.0-0.0-0.00.00.00.00.00.00.00.00.00.00.0-9.1114.320.0-0.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Revenues0.00.00.00.00.00.0-0.1-0.1-0.4-0.00.00.00.0-0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Revenues alk:AlaskaRegional0.00.00.00.00.00.0-0.6-0.7-2.8-0.00.00.00.0-0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

alk:Horizon



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-30
Value-5-6-7-7-8-6-5-5-4-3-4-2-2-1-2-3-1-1-3-2-30-4-3-3-3-3-3-3-3-3-3-4-3-4-4
Percentage of NonoperatingIncomeExpense-125.066.7116.753.842.160.038.541.717.423.133.314.314.310.0-100.0-150.0-50.0-25.0-75.0-50.0-150.00.00.0-150.0-27.342.960.060.094.955.262.121.838.929.821.930.6
Percentage of Revenues-0.3-0.3-0.3-0.3-0.4-0.3-0.2-0.2-0.20.1-0.2-0.1-0.10.0-0.1-0.2-0.10.00.00.00.00.00.00.00.00.00.00.00.00.0-0.3-0.3-0.4-0.4-0.4-0.5
Percentage of Revenues alk:Horizon-4.8-5.5-6.2-6.2-6.8-4.5-3.8-3.6-3.6-2.8-3.5-1.8-2.0-1.0-1.8-2.7-1.0-1.0-2.9-2.0-3.00.0-4.0-3.4-3.3-3.4-3.3-3.2-3.9-4.2-4.0-4.2-4.4-4.0-2.3-2.8

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value-21100-10-10-1-1-10-1-1021210-30000-2-1000000
Percentage of NonoperatingIncomeExpense-50.0-11.1-16.7-0.0-0.010.0-0.08.3-0.07.78.37.1-0.010.0-50.00.0100.025.050.025.00.00.00.00.00.0-0.040.020.02.6-3.0-3.41.1-2.82.3
Percentage of Revenues-0.10.00.00.00.0-0.00.0-0.00.00.0-0.0-0.00.00.0-0.10.00.10.00.00.00.00.00.00.00.00.00.00.00.00.00.0-0.00.0-0.0
Percentage of Revenues us-gaap:IntersegmentElimination1.9-0.9-0.9-0.0-0.00.8-0.00.7-0.00.90.90.9-0.01.00.9-0.0-1.9-1.0-1.9-1.0-0.03.2-0.0-0.0-0.0-0.02.21.10.1-0.2-0.20.2-0.30.3

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value-8562948921367662-22416118353117146160108681631429194118100581746522102412547184675354
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-5.22.83.93.90.10.63.03.10.13.87.68.73.0-2.79.310.78.00.00.00.00.00.00.00.00.00.00.00.00.00.02.54.01.64.87.13.60.6

Income Taxes Paid Net

us-gaap:IncomeTaxesPaidNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value0292000000481151221381391691387154173-65141928766-200
Percentage of IncomeTaxesPaidNet0.0100.0100.00.00.00.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0
Percentage of Revenues0.01.30.10.00.00.00.00.00.0-0.85.50.60.1-3.18.911.31.00.00.00.00.00.00.00.00.00.0-0.20.00.0

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value-2491373232731932241986283270301105932592671931912752351541619816896299109441706948813277
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-15.26.113.511.91.00.110.19.20.3-4.812.814.36.0-2.116.517.914.30.00.00.00.00.00.00.00.00.00.00.00.00.04.76.82.98.1

Net Income Loss

us-gaap:NetIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value-23218132226242321719343732662969911425626018419127423414914819816594289104371636740772874122585
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-14.28.113.511.50.21.19.89.00.2-6.312.614.15.7-2.616.317.413.70.00.00.00.00.00.00.00.00.00.00.00.00.03.96.52.67.711.56.00.6

us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312011-03-31
Value-2323222624217193474
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-14.213.511.50.29.89.00.27.7
Percentage of Revenues us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.0

Assets

us-gaap:Assets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value1336312993129831295112640109121089311055108481074010739107201030299628699703568296533656464806410618162366314606158385862585256445505543654235382519552605233511150164996
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments

alk:AlaskaAirlines



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value19677192071912919050186981685314725153341508816663163821627215735152601094991018630812979227567715367726655647361245832573155825346517750824994489448034610
Percentage of Assets147.2147.8147.3147.1147.9154.4135.2138.7139.1155.1152.5151.8152.7153.2125.9129.4126.4124.4120.7116.8111.6109.6106.7102.5101.099.997.895.494.794.093.592.190.992.591.9
Percentage of Assets147.2147.8147.3147.1147.9154.4135.2138.7139.1155.1152.5151.8152.7153.2125.9129.4126.4124.4120.7116.8111.6109.6106.7102.5101.099.997.895.494.794.093.592.190.992.591.9
Percentage of Assets alk:AlaskaAirlines100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

alk:Horizon



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value11831266123112221209122910371039945929914834719690716729717718763781821818836857849840850868825823850864851846794816747
Percentage of Assets8.99.79.59.49.611.39.59.48.78.68.57.87.06.98.210.410.511.011.612.112.813.213.413.614.014.414.514.814.615.015.715.915.816.315.115.614.9
Percentage of Assets8.99.79.59.49.611.39.59.48.78.68.57.87.06.98.210.410.511.011.612.112.813.213.413.614.014.414.514.814.615.015.715.915.816.315.115.614.9
Percentage of Assets alk:Horizon100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:MaterialReconcilingItems



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value-7497-7480-7377-7321-7267-7170-4869-5318-5185-6839-6557-6386-6152-5988547952004929473441613877363835523324312429132762240320701832
Percentage of Assets-56.1-57.6-56.8-56.5-57.5-65.7-44.7-48.1-47.8-63.7-61.1-59.6-59.7-60.163.073.972.272.563.459.856.857.553.349.548.147.341.035.433.3
Percentage of Assets-56.1-57.6-56.8-56.5-57.5-65.7-44.7-48.1-47.8-63.7-61.1-59.6-59.7-60.163.073.972.272.563.459.856.857.553.349.548.147.341.035.433.3
Percentage of Assets us-gaap:MaterialReconcilingItems100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Liabilities

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value133631299312983129511264010912108931105510848107401073910720103029962869970356829653365646480641061816236631460615838586258525644550554235382519552605233511150164996
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value40154331425239733746375137913593343937213491326430142931286426272455241123652219216621272229220020952029180215431462142112831218117312641206117011058726611025
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets30.033.332.830.729.634.434.832.531.734.632.530.429.329.432.937.335.936.936.034.233.834.435.734.834.634.830.726.425.925.823.722.622.624.023.122.922.017.50.00.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value-482-465-421-422-433-448-428-435-440-380-305-303-310-183-436-390-256-260-263-267-240-328-133
Percentage of StockholdersEquity-12.0-10.7-9.9-10.6-11.6-11.9-11.3-12.1-12.8-10.2-10.4-12.6-14.6-9.0-30.7-33.2-20.2-21.5-22.5-24.2-27.5-49.6-13.0
Percentage of Assets-3.6-3.6-3.2-3.3-3.4-4.1-3.9-3.9-4.1-3.5-3.1-4.6-5.0-3.1-7.9-7.5-4.9-5.0-5.2-5.3-4.80.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value31430529727026123222419819016411073296538660840843838828815767915899
Percentage of StockholdersEquity7.87.07.06.87.06.25.95.55.54.43.83.013.926.546.471.666.769.570.873.887.9138.287.7
Percentage of Assets2.32.32.32.12.12.12.11.81.81.51.11.14.89.212.016.216.016.016.216.315.40.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value111111111111169703737373737354342
Percentage of StockholdersEquity0.00.00.00.00.00.00.00.00.00.00.00.00.03.44.93.23.03.13.23.34.16.54.2
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.01.21.30.70.70.70.70.70.70.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value485651334996471744984534455043734219445435682890214416071127810746669640566315193329
Percentage of StockholdersEquity120.9118.5117.5118.7120.1120.9120.0121.7122.7119.7121.7119.9100.879.279.369.159.155.554.751.236.129.232.1
Percentage of Assets36.339.538.536.435.641.641.839.638.941.535.844.234.727.520.515.614.212.812.511.36.30.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value-674-643-621-593-581-568-556-544-531-518-443-250-4-20-125-107-79-72-46-5-161-112
Percentage of StockholdersEquity-16.8-14.8-14.6-14.9-15.5-15.1-14.7-15.1-15.4-13.9-15.1-10.4-0.2-0.10.0-10.7-8.5-6.6-6.2-4.2-0.7-24.4-11.0
Percentage of Assets-5.0-4.9-4.8-4.6-4.6-5.2-5.1-4.9-4.9-4.8-4.4-3.8-0.1-0.00.0-2.4-2.0-1.5-1.4-0.9-0.10.00.0
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Assets Current

us-gaap:AssetsCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value25722037220222182001178720562216211421462214242522132050360020031923166317151654177617561799202019341762193519861839173716981656159517261675159616621634
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets19.215.717.017.115.816.418.920.019.520.020.622.621.520.641.428.528.225.526.125.527.728.428.832.031.930.233.033.932.631.631.330.830.732.832.031.233.132.7

Cash

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-31
Value81122123724421510517410217719414419818332818188178738845511073422908041579512227354810267676089129108117164283204
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.11.71.81.91.71.01.60.91.61.81.31.81.83.320.91.21.11.11.30.70.81.70.50.31.51.40.71.01.72.20.50.70.92.01.31.31.21.80.00.00.03.30.00.0

Receivables Net Current

us-gaap:ReceivablesNetCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value279323377389358366422411350341301326321302232254235212205194187259178203212152182195188130185169168136148167161120111
Percentage of ReceivablesNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.12.52.93.02.83.43.93.73.23.22.83.03.13.02.73.63.43.23.13.02.94.22.93.23.52.63.13.33.32.43.43.13.12.62.83.23.22.42.2

us-gaap:ContractWithCustomerSalesChannel

alk:MileagePlanRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value88105103122115119106103101
Percentage of ReceivablesNetCurrent31.532.527.331.432.132.525.125.129.6
Percentage of Assets0.70.80.80.90.91.11.00.90.9
Percentage of Assets alk:MileagePlanRevenue0.00.00.00.00.00.00.00.00.0

Inventory Net

us-gaap:InventoryNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value687263555860575762575752504744454551525852586461586060596158524745444452454545
Percentage of InventoryNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.50.60.50.40.50.50.50.50.60.50.50.50.50.50.50.60.70.80.80.90.80.91.01.01.01.01.01.01.11.11.00.90.80.90.81.00.90.90.9

Other Assets Current

Prepaid Expense And Other Assets Current

us-gaap:PrepaidExpenseAndOtherAssetsCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value1001211431471491251801801741271161251321219897797274871021051001341249510511413212311612110093106
Percentage of PrepaidExpenseAndOtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.70.91.11.11.21.11.71.61.61.21.11.21.31.21.11.41.21.11.11.31.61.71.62.12.01.61.81.92.32.22.12.21.91.82.1

Property Plant And Equipment Gross

us-gaap:PropertyPlantAndEquipmentGross



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value1016110388102271005198621002396629584941492759308906188178595790877437529741672687165688166166494629160685961582657155564547252885230506649964853476346264506
Percentage of PropertyPlantAndEquipmentGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets76.080.078.877.678.091.988.786.786.886.486.784.585.686.390.9110.1110.3113.5110.7110.6107.3107.0104.199.6100.1102.199.497.798.699.497.597.297.595.092.793.292.290.2

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value330734863393330732333242316730913011299130783059300829292877278426992614253424602384231722502189213820682034199019251863180517401727166516461603156115091339
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets24.726.826.125.525.629.729.128.027.827.828.728.529.229.433.139.639.540.038.638.037.237.536.134.735.335.434.734.034.133.833.232.132.132.131.330.630.630.126.8

Property Plant And Equipment Net

us-gaap:PropertyPlantAndEquipmentNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value68546902683467446629678164956493640362846230600258095666503149594830480247344705449742994244410239303893379237253639360935473503340133503249320231173167
Percentage of PropertyPlantAndEquipmentNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets51.353.152.652.152.462.159.658.759.058.558.056.056.456.957.870.570.773.572.172.670.269.668.165.064.866.764.763.764.565.665.465.165.563.762.162.662.163.4

Goodwill

us-gaap:Goodwill



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value194319431943194319431943194319431943194319341940194219340
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets14.515.015.015.015.417.817.817.617.918.118.018.118.919.40.0

Intangible Assets Net Excluding Goodwill

us-gaap:IntangibleAssetsNetExcludingGoodwill



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value1101221231251271271281301321331351371391430
Percentage of IntangibleAssetsNetExcludingGoodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets0.80.90.91.01.01.21.21.21.21.21.31.31.31.40.0

Deferred Tax Assets Liabilities Net

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value30027823422522527427127325623422621619916968737668115121137126193192197179126128143120129138148127136223211167143
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.22.11.81.71.82.52.52.52.42.22.12.01.91.70.81.01.11.01.81.92.12.03.13.03.33.12.12.22.52.22.42.62.82.52.64.34.13.32.9

Liabilities Current

us-gaap:LiabilitiesCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value37303201334635343386294228883036299227002765297428352535212320612069180618541927188016711767186417551580165017561598150116641673150915181628148414241269
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets27.924.625.827.326.827.026.527.527.625.125.727.727.525.424.429.330.327.628.229.729.327.028.329.529.027.128.130.028.327.330.731.129.128.931.129.028.425.4

Debt Current

Long Term Debt Current

Accounts Payable Current

us-gaap:AccountsPayableCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value11914612015615713211411510212097959592717863636156576268717564607110165701101291038871596063
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.91.10.91.21.21.21.01.00.91.10.90.90.90.90.81.10.91.00.90.90.91.01.11.11.21.11.01.21.81.21.32.02.42.01.71.41.21.21.3

Other Accrued Liabilities Current

Liabilities Noncurrent

us-gaap:LiabilitiesNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value44154197394139063844260225302428235523382116201319221851185118381774174517521705171416971530150514901475162817391744171215191453141312981244118111731155
Percentage of LiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets33.032.330.430.230.423.823.222.021.721.819.718.818.718.621.326.126.026.726.726.326.727.524.523.824.625.327.829.730.931.128.027.027.224.723.823.123.423.1

Long Term Debt

us-gaap:LongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value22621499170918261964210320292312244925692701280628632964213662664768671074576880382585983487189392494610321066114012471306139214081534
Percentage of LongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets16.911.513.214.115.519.318.620.922.623.925.226.227.829.824.68.99.510.510.811.512.013.013.213.613.814.915.215.816.818.719.621.023.225.226.526.930.6

us-gaap:DebtInstrument

alk:Fixedratenotespayableduethrough2029



Period End2020-03-312019-12-312019-09-302018-12-31
Value457475569642
Percentage of LongTermDebt20.231.733.330.5
Percentage of Assets3.43.74.45.9
Percentage of Assets alk:Fixedratenotespayableduethrough20290.00.00.00.0

alk:Variableratenotespayableduethrough2029Member



Period End2020-03-312019-12-312019-09-302018-12-31
Value1816103211501473
Percentage of LongTermDebt80.368.867.370.0
Percentage of Assets13.67.98.913.5
Percentage of Assets alk:Variableratenotespayableduethrough2029Member0.00.00.00.0

us-gaap:LongtermDebtType

alk:VariableRatedebtwithinterestrateswap



Period End2020-03-312019-09-30
Value694745
Percentage of LongTermDebt30.743.6
Percentage of Assets5.25.7
Percentage of Assets alk:VariableRatedebtwithinterestrateswap0.00.0

Long Term Debt Noncurrent

Deferred Tax Liabilities Noncurrent

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value577571467522513503470464458453323336334331272271270270249247247246124123122123461470479489447452458463336361364367421
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.34.43.64.04.14.64.34.24.24.23.03.13.23.33.13.94.04.13.83.83.94.02.01.92.02.17.98.08.58.98.28.48.58.96.46.97.17.38.4

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value253232213197210418428417423451429427438417355366359362341339332327312315309308318318332334213204184176170148108123148
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.91.81.61.51.73.83.93.83.94.24.04.04.34.24.15.25.35.55.25.25.25.35.05.05.15.35.45.45.96.13.93.83.43.43.22.82.12.53.0

Stockholders Equity

us-gaap:StockholdersEquity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value40154331425239733746375137913593343937213491326430142931286426272455241123652219216621272229220020952029180215431462142112831218117312641206117011058726611025
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets30.033.332.830.729.634.434.832.531.734.632.530.429.329.432.937.335.936.936.034.233.834.435.734.834.634.830.726.425.925.823.722.622.624.023.122.922.017.50.00.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value-482-465-421-422-433-448-428-435-440-380-305-303-310-183-436-390-256-260-263-267-240-328-133
Percentage of StockholdersEquity-12.0-10.7-9.9-10.6-11.6-11.9-11.3-12.1-12.8-10.2-10.4-12.6-14.6-9.0-30.7-33.2-20.2-21.5-22.5-24.2-27.5-49.6-13.0
Percentage of Assets-3.6-3.6-3.2-3.3-3.4-4.1-3.9-3.9-4.1-3.5-3.1-4.6-5.0-3.1-7.9-7.5-4.9-5.0-5.2-5.3-4.80.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value31430529727026123222419819016411073296538660840843838828815767915899
Percentage of StockholdersEquity7.87.07.06.87.06.25.95.55.54.43.83.013.926.546.471.666.769.570.873.887.9138.287.7
Percentage of Assets2.32.32.32.12.12.12.11.81.81.51.11.14.89.212.016.216.016.016.216.315.40.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value111111111111169703737373737354342
Percentage of StockholdersEquity0.00.00.00.00.00.00.00.00.00.00.00.00.03.44.93.23.03.13.23.34.16.54.2
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.01.21.30.70.70.70.70.70.70.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value485651334996471744984534455043734219445435682890214416071127810746669640566315193329
Percentage of StockholdersEquity120.9118.5117.5118.7120.1120.9120.0121.7122.7119.7121.7119.9100.879.279.369.159.155.554.751.236.129.232.1
Percentage of Assets36.339.538.536.435.641.641.839.638.941.535.844.234.727.520.515.614.212.812.511.36.30.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value-674-643-621-593-581-568-556-544-531-518-443-250-4-20-125-107-79-72-46-5-161-112
Percentage of StockholdersEquity-16.8-14.8-14.6-14.9-15.5-15.1-14.7-15.1-15.4-13.9-15.1-10.4-0.2-0.10.0-10.7-8.5-6.6-6.2-4.2-0.7-24.4-11.0
Percentage of Assets-5.0-4.9-4.8-4.6-4.6-5.2-5.1-4.9-4.9-4.8-4.4-3.8-0.1-0.00.0-2.4-2.0-1.5-1.4-0.9-0.10.00.0
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Value

us-gaap:CommonStockValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value111111111111111111111111696970707070707071373737373735
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.01.11.21.21.21.21.31.31.31.30.70.70.70.70.70.7

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value4856513349964717449845344550437342194454411738883629356834883266303928902724247422662144201218311684160715421268116411271082918851810746669640566315
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets36.339.538.536.435.641.641.839.638.941.538.336.335.235.840.146.444.544.241.538.235.434.732.329.027.827.526.321.720.620.519.916.915.815.614.212.812.511.36.3

Treasury Stock Value

us-gaap:TreasuryStockValue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value67464362159358156855654453151849446644344344444437725012787455122100001251077972465
Percentage of TreasuryStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0100.0100.0100.0100.0100.0100.0
Percentage of Assets5.04.94.84.64.65.25.14.94.94.84.64.34.34.45.16.35.53.81.90.10.10.10.10.10.00.00.40.00.00.00.02.42.01.51.40.90.1

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value-482-465-421-422-433-448-428-435-440-380-289-294-299-305-284-287-294-303-303-304-305-310-178-178-181-183-414-424-429-436-373-380-382-390-256-260-263-267-240
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-3.6-3.6-3.2-3.3-3.4-4.1-3.9-3.9-4.1-3.5-2.7-2.7-2.9-3.1-3.3-4.1-4.3-4.6-4.6-4.7-4.8-5.0-2.9-2.8-3.0-3.1-7.1-7.2-7.6-7.9-6.9-7.0-7.1-7.5-4.9-5.0-5.2-5.3-4.8

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value3334134856546820926042030623327361447018030737452535534037551413825739324221218311854
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues2.015.314.624.724.910.111.819.516.7-3.912.929.226.9-4.119.625.039.00.00.00.00.00.00.00.00.00.017.612.36.6

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value-127-83-178-344-186-298135-304-16410-171-483-488-1981-51-254-336-203-133-173-42177-36-418-164-151-173-33-47
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-7.8-3.7-7.5-15.0-9.9-14.46.1-14.1-9.0-0.2-8.1-23.0-27.945.0-3.3-17.0-24.90.00.00.00.00.00.00.00.00.0-16.7-3.5-5.8

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value684-275-175-192-17119-319-191-156-193-156-116-1273111481-117-184-167-164-208-149-142-209-43-68-88-63-114-53
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues41.8-12.3-7.3-8.4-9.10.9-14.4-8.9-8.53.2-7.4-5.5-7.3-7.194.6-7.8-13.70.00.00.00.00.00.00.00.00.0-6.1-11.8-6.4

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value3334134856546820926042030623327361447018030737452535534037551413825739324221218311854
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues2.015.314.624.724.910.111.819.516.7-3.912.929.226.9-4.119.625.039.00.00.00.00.00.00.00.00.00.017.612.36.6

Net Income Loss

us-gaap:NetIncomeLoss



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value-23218132226242321719343732662969911425626018419127423414914819816594289104371636740772874122585
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-14.28.113.511.50.21.19.89.00.2-6.312.614.15.7-2.616.317.413.70.00.00.00.00.00.00.00.00.00.00.00.00.03.96.52.67.711.56.00.6

us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312011-03-31
Value-2323222624217193474
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-14.213.511.50.29.89.00.27.7
Percentage of Revenues us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.0

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value108106106105106108999794979590908210192888481797676757370676869656563626160575856
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Increase Decrease In Other Operating Capital Net

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value-127-83-178-344-186-298135-304-16410-171-483-488-1981-51-254-336-203-133-173-42177-36-418-164-151-173-33-47
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-7.8-3.7-7.5-15.0-9.9-14.46.1-14.1-9.0-0.2-8.1-23.0-27.945.0-3.3-17.0-24.90.00.00.00.00.00.00.00.00.0-16.7-3.5-5.8

Payments To Acquire Property Plant And Equipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value119169194218115406131188235185329296216169169221119163109280279135209257931039814925
Percentage of PaymentsToAcquirePropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value684-275-175-192-17119-319-191-156-193-156-116-1273111481-117-184-167-164-208-149-142-209-43-68-88-63-114-53
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues41.8-12.3-7.3-8.4-9.10.9-14.4-8.9-8.53.2-7.4-5.5-7.3-7.194.6-7.8-13.70.00.00.00.00.00.00.00.00.0-6.1-11.8-6.4

Proceeds From Issuance Of Long Term Debt

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value6030622013939326328613812013210658101156362136233523352233273788598939
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Payments Of Dividends

us-gaap:PaymentsOfDividends



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-06-302013-03-31
Value4544434343403940393737373734343434242626261717171700
Percentage of PaymentsOfDividends100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0

Payments Of Dividends

us-gaap:PaymentsOfDividends



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-06-302013-03-31
Value4544434343403940393737373734343434242626261717171700
Percentage of PaymentsOfDividends100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0

Payments For Repurchase Of Common Stock

us-gaap:PaymentsForRepurchaseOfCommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value3122281213131213122528220006612712411916010210615953301982610
Percentage of PaymentsForRepurchaseOfCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value6030622013939326328613812013210658101156362136233523352233273788598939
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of LongTermDebtAndCapitalLeaseObligations0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Effective Income Tax Rate Continuing Operations

Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number

Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price

Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period

Share Based Compensation

us-gaap:ShareBasedCompensation



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value9945111317981218121376493859-2161741456
Percentage of ShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Deferred Tax Liabilities

Unrecognized Tax Benefits

Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions

Operating Lease Right Of Use Asset

us-gaap:OperatingLeaseRightOfUseAsset



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value158417111647169617150
Percentage of OperatingLeaseRightOfUseAsset100.0100.0100.0100.0100.00.0

Cash And Cash Equivalents Period Increase Decrease

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312015-12-31
Value82223224925422511418410818319714419832873
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AircraftType

alk:AircraftPermanentlyParked

alk:Airbus



Period End2020-03-31
Value12.0
Percentage of AircraftPermanentlyParked100.0

alk:Q400



Period End2020-03-31
Value2.0
Percentage of AircraftPermanentlyParked16.7

us-gaap:ContractWithCustomerSalesChannel

alk:ContractwithCustomerLiabilityIncreaseFromIssuanceofCredits

alk:MileagePlanRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value207239241229222227229218184219204
Percentage of ContractwithCustomerLiabilityIncreaseFromIssuanceofCredits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

alk:NumberOfMainlineAircraftParked



Period End2020-03-31
Value146.0
Percentage of NumberOfMainlineAircraftParked100.0

us-gaap:SubsequentEventType

us-gaap:SubsequentEvent



Period End2020-05-14
Value10.0
Percentage of NumberOfMainlineAircraftParked0.0

alk:OperatingExpensesExcludingFuel



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value15731506148114221431147914021410139414041313126512441045941875890909837804796758755752723724710688666665648634654636
Percentage of OperatingExpensesExcludingFuel100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments

alk:AirGroupAdjusted



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value1410150114761414140514391380137113631374128912411204964919861890877837804796788755752723724710688666665648632628626
Percentage of OperatingExpensesExcludingFuel89.699.799.799.498.297.398.497.297.897.998.298.196.892.297.798.4100.096.5100.0100.0100.0104.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.795.998.4

alk:AlaskaMainline



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value115912331226116711521185112611351131115610771026998776727679701702667645639634605602576588569547531532519504498497
Percentage of OperatingExpensesExcludingFuel73.781.982.882.180.580.180.380.581.182.382.081.180.274.377.377.678.877.279.780.280.383.680.180.179.781.280.179.579.880.080.279.476.178.1

alk:AlaskaRegional



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value269280275268274269267249239226219206200189202192186181181169164159162151151144149147144139136136138132
Percentage of OperatingExpensesExcludingFuel17.118.618.618.819.118.219.017.717.116.116.716.316.118.121.521.920.919.921.621.020.621.021.520.120.919.921.021.421.820.921.121.521.120.9

alk:Horizon



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value92999495971201181231041031051161031029910110510193909192858686808489868378828390
Percentage of OperatingExpensesExcludingFuel5.86.66.36.76.88.18.48.77.57.38.09.28.39.810.511.511.811.111.111.211.412.111.311.411.911.011.812.912.912.512.113.112.814.2

alk:SpecialRevenueandCharges



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-30
Value1635826223931242440221400000000000
Percentage of OperatingExpensesExcludingFuel10.40.30.61.81.62.82.21.81.93.22.31.60.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value-110-111-119-116-118-135-131-136-111-111-112-107-97-103-109-111-102-107-104-100-98-97-97-87-90-88-92-95-96-88-86-90-92-94
Percentage of OperatingExpensesExcludingFuel-7.0-7.4-8.0-8.2-8.2-9.1-9.3-9.6-8.0-7.9-8.5-8.5-7.8-9.9-11.6-12.7-11.5-11.8-12.4-12.4-12.3-12.8-12.8-11.6-12.4-12.2-13.0-13.8-14.5-13.3-13.4-14.3-14.1-14.8

alk:OtherNonoperatingIncomeExpenseOther



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value5-3-7-10-7-1-1245345649999867918157655322
Percentage of OtherNonoperatingIncomeExpenseOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments

alk:AirGroupAdjusted



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value5-3-7-10-7-1-1245345649999867918157655322
Percentage of OtherNonoperatingIncomeExpenseOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

alk:AlaskaMainline



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value6-3-7-10-51-535334537777757918866655322
Percentage of OtherNonoperatingIncomeExpenseOther120.0100.0100.0100.071.4-100.041.775.0100.0100.075.080.083.375.077.877.877.877.887.583.3100.0100.0100.0800.0120.085.797.094.489.8103.079.377.8

alk:AlaskaRegional



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value0000-2-2-7000000000000-101-1-8-10000000
Percentage of OtherNonoperatingIncomeExpenseOther0.0-0.0-0.0-0.028.6200.058.30.00.00.00.00.00.00.00.00.00.00.00.0-16.70.011.1-5.6-800.0-20.00.00.00.00.00.00.00.0

alk:Horizon



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value00000001010100010-1120-11110000000
Percentage of OtherNonoperatingIncomeExpenseOther0.0-0.0-0.0-0.0-0.0-0.0-0.025.00.033.30.020.00.00.00.011.10.0-11.112.533.30.0-11.15.6100.020.00.04.57.46.83.06.929.6

us-gaap:IntersegmentElimination



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value-100000000-110112123000000-11000000
Percentage of OtherNonoperatingIncomeExpenseOther-20.0-0.0-0.0-0.0-0.0-0.0-0.00.00.0-33.325.00.016.725.022.211.122.233.30.00.00.00.00.00.0-20.014.3-1.5-1.93.4-6.113.8-7.4

alk:RegionalCarrierExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value374142424140383937373027272325242320201715
Percentage of RegionalCarrierExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

alk:SpecialItemsImpairmentChargesAndOther



Period End2020-03-312019-03-31
Value1600
Percentage of SpecialItemsImpairmentChargesAndOther100.00.0

us-gaap:StatementEquityComponents

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312011-03-31
Value979128912-4
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AircraftMaintenanceMaterialsAndRepairs



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-30
Value1159610611512011510710610712088968773646568716752636358575154676655545049495355
Percentage of AircraftMaintenanceMaterialsAndRepairs100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AircraftRental



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-30
Value8184828283828277747070696534252629272626262627292829303029292828293033
Percentage of AircraftRental100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs



Period End2020-03-31
Value5
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs100.0

us-gaap:AssetImpairmentCharges



Period End2020-03-31
Value145
Percentage of AssetImpairmentCharges100.0

us-gaap:AircraftType

alk:Airbus



Period End2020-03-31
Value83
Percentage of AssetImpairmentCharges57.2

alk:Q400



Period End2020-03-31
Value62
Percentage of AssetImpairmentCharges42.8

us-gaap:AircraftType, us-gaap:ImpairedLongLivedAssetsHeldAndUsedByType

alk:Airbus, alk:Aircraft



Period End2020-03-31
Value11
Percentage of AssetImpairmentCharges7.6

alk:Airbus, alk:LeaseReturnCosts



Period End2020-03-31
Value8
Percentage of AssetImpairmentCharges5.5

alk:Airbus, alk:OperatingLeaseAsset



Period End2020-03-31
Value62
Percentage of AssetImpairmentCharges42.8

alk:Airbus, us-gaap:DisposalGroupHeldforsaleNotDiscontinuedOperations



Period End2020-03-31
Value0.0
Percentage of AssetImpairmentCharges0.0

alk:Airbus, us-gaap:Inventories



Period End2020-03-31
Value2
Percentage of AssetImpairmentCharges1.4

alk:Q400, alk:Aircraft



Period End2020-03-31
Value58
Percentage of AssetImpairmentCharges40.0

alk:Q400, alk:LeaseReturnCosts



Period End2020-03-31
Value0.0
Percentage of AssetImpairmentCharges0.0

alk:Q400, alk:OperatingLeaseAsset



Period End2020-03-31
Value0.0
Percentage of AssetImpairmentCharges0.0

alk:Q400, us-gaap:DisposalGroupHeldforsaleNotDiscontinuedOperations



Period End2020-03-31
Value4
Percentage of AssetImpairmentCharges2.8

alk:Q400, us-gaap:Inventories



Period End2020-03-31
Value0.0
Percentage of AssetImpairmentCharges0.0

us-gaap:ImpairedLongLivedAssetsHeldAndUsedByType

alk:Aircraft



Period End2020-03-31
Value69
Percentage of AssetImpairmentCharges47.6

alk:LeaseReturnCosts



Period End2020-03-31
Value8
Percentage of AssetImpairmentCharges5.5

alk:OperatingLeaseAsset



Period End2020-03-31
Value62
Percentage of AssetImpairmentCharges42.8

us-gaap:DisposalGroupHeldforsaleNotDiscontinuedOperations



Period End2020-03-31
Value4
Percentage of AssetImpairmentCharges2.8

us-gaap:Inventories



Period End2020-03-31
Value2
Percentage of AssetImpairmentCharges1.4

us-gaap:BusinessCombinationAcquisitionRelatedCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value35582620223963024244081221403200
Percentage of BusinessCombinationAcquisitionRelatedCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.00.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect



Period End2020-03-312019-03-31
Value590111
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect100.0100.0

us-gaap:CommonStockDividendsPerShareDeclared



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312014-02-132013-09-302013-06-302013-03-312012-09-30
Value0.3750.350.350.350.350.320.320.320.320.30.30.30.30.275000000000000130.2750.2750.2750.200000000000000070.20.20.20.1250.1250.1250.250.250.20.00.00.0
Percentage of CommonStockDividendsPerShareDeclared100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:SubsequentEventType

us-gaap:SubsequentEvent



Period End2020-02-182019-02-192018-02-202017-02-212016-02-11
Value0.3750.350.320.30.275
Percentage of CommonStockDividendsPerShareDeclared0.00.00.00.00.0

us-gaap:ContractWithCustomerSalesChannel

us-gaap:ContractWithCustomerLiabilityRevenueRecognized

alk:PassengerRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value489-5198947443277943482389
Percentage of ContractWithCustomerLiabilityRevenueRecognized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProductOrService, us-gaap:ContractWithCustomerSalesChannel

alk:MileagePlanServicesOther, alk:MileagePlanRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-22-27-33-23-28-24-22-25-19-19-10
Percentage of ContractWithCustomerLiabilityRevenueRecognized-4.5540.0-173.7-25.8-5.9-55.8-81.5-31.6-4.4-237.5-43.5

alk:PassengerServices, alk:MileagePlanRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-152-193-186-172-153-160-153-167-139-136-134
Percentage of ContractWithCustomerLiabilityRevenueRecognized-31.13860.0-978.9-193.3-32.3-372.1-566.7-211.4-32.0-1700.0-582.6

us-gaap:CostOfServicesCatering



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value495557534953535550505050
Percentage of CostOfServicesCatering100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value-9-10-9-9-9-8-9-8-8-6-7-6
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value282424232427272627262726
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanInterestCost

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value192223222220201920191918
Percentage of DefinedBenefitPlanInterestCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeStatementLocation, us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

alk:LaborAndRelatedExpense, us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value131110111212121010
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NonoperatingIncomeExpense, us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value0787111-2-2
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost0.063.680.063.68.38.38.3-20.0-20.0

us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanServiceCost

us-gaap:PensionPlansDefinedBenefit



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value13101110111212121291010
Percentage of DefinedBenefitPlanServiceCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:DividendsCash

us-gaap:RetainedEarnings



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value45434343403940
Percentage of DividendsCash100.0100.0100.0100.0100.0100.0100.0

us-gaap:FuelCosts



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value384470486502420539513475409396368344339238225201167213245261235306394360358363372381336431318420397194220255207
Percentage of FuelCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments

alk:AirGroupAdjusted



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value375475486499424487508497422410373342329242222211169212240267235312390373366383371369357362338335326276
Percentage of FuelCosts97.7101.1100.099.4101.090.499.0104.6103.2103.5101.499.497.1101.798.7105.0101.299.598.0102.3100.0102.099.0103.6102.2105.599.796.9106.383.9106.279.982.2142.2

alk:AlaskaMainline



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value313398411422358415438432367358328304292207188180144182205232203271338324318337327323312316294292285238
Percentage of FuelCosts81.584.784.684.185.277.085.490.989.790.489.188.486.187.083.689.686.285.483.788.986.488.685.890.088.892.887.984.892.773.392.369.671.7122.6

alk:AlaskaRegional



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value62777577667270655552453936353431253035353241524948464446454544434138
Percentage of FuelCosts16.116.415.415.315.713.413.613.713.413.112.211.310.614.715.115.415.014.114.313.413.613.413.213.613.412.711.812.113.610.513.910.310.419.6

alk:SpecialRevenueandCharges



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-30
Value903-45-22-13-52103-10-25-604-13-8-20112-21
Percentage of FuelCosts2.30.00.6-1.01.0-4.6-3.2-1.40.62.91.3-5.0-1.22.0-2.30.01.0-3.6-2.2-5.50.33.1-6.2

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value0.00.00.00.00.00.00.00.00.00.00.0-1000000.01000000.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of FuelCosts0.00.00.00.00.00.00.00.00.00.00.0-0.30.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value-31724341635163628425961494274791522314024202922594373762402423162651524631695926510966125471201989410
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments

alk:AirGroupAdjusted



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value-1452434213622812831127624165446505202308427424290292442370240206320252144251170712441784621114448
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments45.7100.0101.2103.1466.7355.6109.5106.6400.0110.7104.4105.4132.9133.3106.2101.099.3112.7101.198.4100.085.1101.395.194.754.2100.6120.392.0163.870.1168.9307.940.4

alk:AlaskaMainline



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value-852323783344913831428869185422490215288383392278262386331228183282231138215150632101553317112240
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments26.895.590.995.2816.7383.3110.6111.21150.0124.298.8102.3141.4124.795.393.395.2101.288.388.095.075.689.287.290.846.488.8106.879.3142.550.0136.6260.433.4

alk:AlaskaRegional



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value-7322312-35-18-13-20-49-252026-62135241323452972029214301542519634156
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments23.00.85.53.4-583.3-50.0-4.6-7.7-816.7-16.84.75.4-3.99.18.75.74.58.910.37.72.98.39.27.92.66.58.96.89.517.79.927.833.85.4

alk:Horizon



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-30
Value851110127710335-9-7097-241086311036648474-19211-1
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments-2.52.12.62.8200.019.42.53.950.02.01.2-1.9-4.60.02.21.7-0.71.52.32.12.51.23.50.02.01.33.66.83.03.810.53.5-41.32.45.9-1.3

alk:SpecialRevenueandCharges



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-30
Value-172-5-11-22-27-17-18-19-26-50-25-42-560-4138212-1-1221
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments54.3-1.2-3.1-366.7-9.5-6.6-300.0-4.4-5.4-32.9-6.2-1.00.7-1.11.60.0-1.34.95.345.8-0.6-20.37.9

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value5496213-212-1-20-1011312-10-20-10-100000-10
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments-1.61.62.21.733.32.81.1-0.816.71.3-0.2-0.40.0-0.40.00.20.31.20.20.5-0.40.0-0.60.0-0.70.0-0.60.00.2-0.3-0.3-0.6-2.1-0.7

us-gaap:IncreaseDecreaseInContractWithCustomerLiability



Period End2020-03-312019-03-31
Value210328
Percentage of IncreaseDecreaseInContractWithCustomerLiability100.0100.0

us-gaap:IncreaseDecreaseInDeferredIncomeTaxes



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value44-22-125-60-2-24-55-65-2198-85-84-48-47-6-498-73-27386-87-13-5-9-18-25-43
Percentage of IncreaseDecreaseInDeferredIncomeTaxes100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInDeferredRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value331922344143542626173114123121236151519819148-1-2-4-15
Percentage of IncreaseDecreaseInDeferredRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestCostsCapitalizedAdjustment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value34434454545444678998865456655
Percentage of InterestCostsCapitalizedAdjustment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestCostsIncurred



Period End2020-03-312019-03-31
Value1322
Percentage of InterestCostsIncurred100.0100.0

us-gaap:StatementBusinessSegments

alk:AirGroupAdjusted



Period End2020-03-312019-03-31
Value1322
Percentage of InterestCostsIncurred100.0100.0

alk:AlaskaMainline



Period End2020-03-312019-03-31
Value1221
Percentage of InterestCostsIncurred92.395.5

alk:Horizon



Period End2020-03-312019-03-31
Value58
Percentage of InterestCostsIncurred38.536.4

us-gaap:IntersegmentElimination



Period End2020-03-312019-03-31
Value-4-7
Percentage of InterestCostsIncurred-30.8-31.8

us-gaap:InterestPaidCapitalized



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value3434545544
Percentage of InterestPaidCapitalized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments

alk:AirGroupAdjusted



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value3434545544
Percentage of InterestPaidCapitalized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

alk:AlaskaMainline



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value3434444534
Percentage of InterestPaidCapitalized100.0100.0100.0100.080.0100.080.0100.075.0100.0

alk:Horizon



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value0.00.00.00.01000000.00.01000000.00.01000000.00.0
Percentage of InterestPaidCapitalized0.00.00.00.020.00.020.00.025.00.0

us-gaap:InterestPaidNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value912141618122115241626162612408-111721051115152528
Percentage of InterestPaidNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InvestmentIncomeInterest



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value911111199111089997777655656555544454467777
Percentage of InvestmentIncomeInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementBusinessSegments

alk:AirGroupAdjusted



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value911111199111089997777655656555544454467
Percentage of InvestmentIncomeInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

alk:AlaskaMainline



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value141617171614151311121197776645555555544444478
Percentage of InvestmentIncomeInterest155.6145.5154.5154.5177.8155.6136.4130.0137.5133.3122.2100.0100.0100.0100.085.7100.080.0100.083.3100.083.3100.0100.0100.0100.0100.0100.0104.486.3100.0102.2112.7114.5

alk:Horizon



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.01000000.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of InvestmentIncomeInterest0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.014.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:IntersegmentElimination



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value-5-5-6-6-7-5-4-3-3-3-20000001010100000000000-1
Percentage of InvestmentIncomeInterest-55.6-45.5-54.5-54.5-77.8-55.6-36.4-30.0-37.5-33.3-22.20.00.00.00.00.00.020.00.016.70.016.70.00.00.00.00.00.0-4.413.70.0-2.2-12.7-14.5

us-gaap:LaborAndRelatedExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-30
Value612638608567557561549544536532475469448374340332336331312305306304279281272285258264255258256245242249240
Percentage of LaborAndRelatedExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LandingFeesAndOtherRentals



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-30
Value131143143113132128135110126122124991158889638079806671727464697175606160626259575957
Percentage of LandingFeesAndOtherRentals100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value-3-1-1101261-3-8-5012-10-248-40-34-1-3223-8-1202-11
Percentage of OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value-1-10342-10-3-3011-6024-30-230-2111-4-1101-11
Percentage of OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax100.0100.00.0100.0100.0100.0100.00.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value-194-4-5-3-612531001010-21-11-1-22-1-1152-1-3-1-11-2
Percentage of OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value-510-2-1-210211-11610-23-21-10000-1420-24-6-1
Percentage of OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax100.0100.00.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.00.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value-17-4411115-20752-90456-213790115-132032105771743
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value-1711115752
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax



Period End2020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value-7-8-8-855-7-7-7139-5-5-658-5-5-51-3-5-3217-2-3-2-11-11-10-9-9-10-27-6
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-30
Value-5-11-6-6-620-5-6-588-3-4-421-4-3-3-3-2-3-2129-1-2-1-6-8-6-6-6-6-17-4
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value3250-2-3-2-1-2-11-100010-100001100-112-2
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0100.00.0100.00.00.00.00.0100.0100.00.00.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-30
Value-1-1-10-10-20-1-1-2-20-2-1-2-1-1-2-1-2-1-2-1-2-12-1-21
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax100.0100.0100.00.0100.00.0100.00.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossTax



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value222221221212210121-791115343331022
Percentage of OtherComprehensiveIncomeLossTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-31
Value-25-5-7-50260-311-2-5-51-40-2-3-173-4-81
Percentage of OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax100.0100.0100.0100.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-31
Value-10413145-2-4-13-9113-16-2712-80-57-1-4434-11-1503-13-2
Percentage of OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherCostAndExpenseOperating



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value143148137136138149141141141141150140134989281949782948379678181696567586164545860494847
Percentage of OtherCostAndExpenseOperating100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherLaborRelatedExpenses



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-30
Value738464435432738393740273132313232303232263230292526212123211619171623
Percentage of OtherLaborRelatedExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherOperatingActivitiesCashFlowStatement



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value-21125-2542-24133-2040-144120-7081-1503711-4517-3155095295567-119-106-93-119
Percentage of OtherOperatingActivitiesCashFlowStatement100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsForFlightEquipment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value57701141195333778136135125275244160120140177911187324524584159190659080139
Percentage of PaymentsForFlightEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsForProceedsFromOtherInvestingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value-8-4-12-20-5-11-26-2-8-37-28-1000-2-2-1-5412-2-1429-770180
Percentage of PaymentsForProceedsFromOtherInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireMarketableSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value527364561534351162143291238161398453557185165252358451165308403155166323305280240181284
Percentage of PaymentsToAcquireMarketableSecurities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireOtherProductiveAssets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value3553425429292027292625252018416151818222139324317624
Percentage of PaymentsToAcquireOtherProductiveAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireOtherPropertyPlantAndEquipment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-31
Value274638453340332571342927363125281327181313121824117144
Percentage of PaymentsToAcquireOtherPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromIssuanceOfDebt



Period End2020-03-31
Value425
Percentage of ProceedsFromIssuanceOfDebt100.0

us-gaap:SubsequentEventType

us-gaap:SubsequentEvent



Period End2020-04-222019-02-15
Value50254
Percentage of ProceedsFromIssuanceOfDebt0.00.0

us-gaap:ProceedsFromIssuanceOfSecuredDebt



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312015-09-302014-09-302013-09-30
Value8251020254000000
Percentage of ProceedsFromIssuanceOfSecuredDebt100.0100.00.0100.00.00.00.00.00.00.0

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value-5314224-41801511511135413416114-24031680-7-13
Percentage of ProceedsFromPaymentsForOtherFinancingActivities100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromSaleAndMaturityOfMarketableSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-03-312012-03-312011-03-312010-03-31
Value511446565388275259383173301319528256285324281217140357142417259353341171227239188314261
Percentage of ProceedsFromSaleAndMaturityOfMarketableSecurities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProfessionalAndContractServicesExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-30
Value727572707279707681807677816463606057468676666626054545350504746464340
Percentage of ProfessionalAndContractServicesExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:SellingExpense



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-312012-09-302012-06-302012-03-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value55777787728179887888919781635855495153545345555346475138454441474539443833
Percentage of SellingExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans

us-gaap:CommonStock



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-03-31
Value0.00.3940.0280.3910.320.312
Percentage of StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans0.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodSharesShareBasedCompensation

us-gaap:CommonStock



Period End2020-03-312019-09-302019-03-312018-09-302018-06-302018-03-31
Value0.1230.0110.1340.030.0580.163
Percentage of StockIssuedDuringPeriodSharesShareBasedCompensation100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueEmployeeStockPurchasePlan

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-09-302019-03-312018-09-302018-03-312011-03-31
Value0202018171
Percentage of StockIssuedDuringPeriodValueEmployeeStockPurchasePlan0.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation

us-gaap:AdditionalPaidInCapital



Period End2020-03-312019-09-302019-03-312018-09-302018-06-302018-03-312011-03-31
Value00-30-1-37
Percentage of StockIssuedDuringPeriodValueShareBasedCompensation0.00.0100.00.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:StockRepurchasedDuringPeriodShares

us-gaap:CommonStock



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value0.5380.4650.1940.2150.1930.2040.186
Percentage of StockRepurchasedDuringPeriodShares100.0100.0100.0100.0100.0100.0100.0

us-gaap:StatementEquityComponents

us-gaap:StockRepurchasedDuringPeriodValue

us-gaap:TreasuryStock



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312011-03-31
Value3128121312131326
Percentage of StockRepurchasedDuringPeriodValue100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueByMeasurementBasis

alk:NotesPayableFairValueDisclosureBeforePurchasePriceAccountingFairValueAdjustment

us-gaap:CarryingReportedAmountFairValueDisclosure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value4554735675805126397038388749561175
Percentage of NotesPayableFairValueDisclosureBeforePurchasePriceAccountingFairValueAdjustment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccruedLiabilitiesCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value382431476505480416452483433918886979909878735757809661698736731629680706672612676711568539537558551513491544533501474
Percentage of AccruedLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-312010-12-31
Value6910111-11-17-17-15-500-1-3795-3114014201-26-758
Percentage of AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-312010-12-31
Value-24-5-9-5039761-2-3-3-3-13-14-14-12-13-12-1312-10-12-1110-12-13-18-20-15-5
Percentage of AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value464469422428434440420425431376287291295299278282285288291293296298169170172173403409417-423-380
Percentage of AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AdditionalPaidInCapitalCommonStock



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value3143052972702612322241981901641561351261101039186737056211296399551524538625629657660660674677840843838828815767
Percentage of AdditionalPaidInCapitalCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:AssetsFairValueDisclosure

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312011-09-302011-06-30
Value309336384409367293338376328193223
Percentage of AssetsFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312011-09-302011-06-30
Value10069781007985871852954116211301072929
Percentage of AssetsFairValueDisclosure325.6291.1262.2240.8237.3290.8282.2309.0344.5553.8415.4

us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312011-09-302011-06-30
Value13151314139113941238114512921538145812651153
Percentage of AssetsFairValueDisclosure425.6391.1362.2340.8337.3390.8382.2409.0444.5653.8515.4

us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:AvailableForSaleSecurities

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value309336384409367293338376330328359448416287332433412253
Percentage of AvailableForSaleSecurities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value10059649989748548388851090102110991237127611119651076109310741002
Percentage of AvailableForSaleSecurities325.2286.9259.9238.1232.7286.0261.8289.9309.4335.1344.6284.8267.1336.2324.1252.4260.7396.0

us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:FinancialInstrument

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring, us-gaap:EquityFunds



Period End2020-03-312019-12-312019-09-302018-12-31
Value4650
Percentage of AvailableForSaleSecurities1.31.81.30.0

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring, us-gaap:USTreasuryAndGovernment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value305330379409367293338376328
Percentage of AvailableForSaleSecurities98.798.298.7100.0100.0100.0100.0100.0100.0

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring, us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivables



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value206211201189217190209231209
Percentage of AvailableForSaleSecurities66.762.852.346.259.164.861.861.463.7

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring, us-gaap:CorporateDebtSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value537523609623514520559743726
Percentage of AvailableForSaleSecurities173.8155.7158.6152.3140.1177.5165.4197.6221.3

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring, us-gaap:ForeignGovernmentDebtSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value263125252226292843
Percentage of AvailableForSaleSecurities8.49.26.56.16.08.98.67.413.1

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring, us-gaap:MortgageBackedSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value2131761421208792797899
Percentage of AvailableForSaleSecurities68.952.437.029.323.731.423.420.730.2

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring, us-gaap:USStatesAndPoliticalSubdivisions



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value23232117141091022
Percentage of AvailableForSaleSecurities7.46.85.54.23.83.42.72.76.7

us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value131413001382138312211131122314661351142715961724152712521408152614861255
Percentage of AvailableForSaleSecurities425.2386.9359.9338.1332.7386.0361.8389.9409.4435.1444.6384.8367.1436.2424.1352.4360.7496.0

us-gaap:FairValueByMeasurementFrequency, us-gaap:FinancialInstrument

us-gaap:FairValueMeasurementsRecurring, us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivables



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value206211201189217190209231209
Percentage of AvailableForSaleSecurities66.762.852.346.259.164.861.861.463.7

us-gaap:FairValueMeasurementsRecurring, us-gaap:CorporateDebtSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value537523609623514520559743726
Percentage of AvailableForSaleSecurities173.8155.7158.6152.3140.1177.5165.4197.6221.3

us-gaap:FairValueMeasurementsRecurring, us-gaap:EquityFunds



Period End2020-03-312019-12-312019-09-302018-12-31
Value4650
Percentage of AvailableForSaleSecurities1.31.81.30.0

us-gaap:FairValueMeasurementsRecurring, us-gaap:ForeignGovernmentDebtSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value263125252226292843
Percentage of AvailableForSaleSecurities8.49.26.56.16.08.98.67.413.1

us-gaap:FairValueMeasurementsRecurring, us-gaap:MortgageBackedSecurities



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value2131761421208792797899
Percentage of AvailableForSaleSecurities68.952.437.029.323.731.423.420.730.2

us-gaap:FairValueMeasurementsRecurring, us-gaap:USStatesAndPoliticalSubdivisions



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value23232117141091022
Percentage of AvailableForSaleSecurities7.46.85.54.23.83.42.72.76.7

us-gaap:FairValueMeasurementsRecurring, us-gaap:USTreasuryAndGovernment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value305330379409367293338376328
Percentage of AvailableForSaleSecurities98.798.298.7100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesAmortizedCost



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value130013001400140012001145120014891400140016001725125713981513147812601167114512541110130814821327125014031375116111191143113910811029118810731105
Percentage of AvailableForSaleSecuritiesAmortizedCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:BusinessAcquisitionsPurchasePriceAllocationSubsequentYearsRemainingAdjustments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value22223333334
Percentage of BusinessAcquisitionsPurchasePriceAllocationSubsequentYearsRemainingAdjustments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashCashEquivalentsAndShortTermInvestments



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value21251521161916271436123613971568152816211740192217101580322616071564132812581192131212171343151014201330144514291265125211851185114111401208
Percentage of CashCashEquivalentsAndShortTermInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ContractWithCustomerSalesChannel

us-gaap:ContractWithCustomerLiability

alk:MileagePlanRevenue



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-31
Value2023199019711949191518741831177717511725166116011534
Percentage of ContractWithCustomerLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ContractWithCustomerLiabilityCurrent



Period End2020-03-312019-12-312018-12-31
Value1110900788
Percentage of ContractWithCustomerLiabilityCurrent100.0100.0100.0

us-gaap:DeferredFinanceCostsNet



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value11810111212121415151616171817333
Percentage of DeferredFinanceCostsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredRevenueCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value478750794768757705693667649635
Percentage of DeferredRevenueCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredRevenueNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value1545124011771181115811691138111011021090
Percentage of DeferredRevenueNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAndOtherLiabilitiesNoncurrent



Period End2020-03-312019-12-31
Value665715
Percentage of DeferredTaxAndOtherLiabilitiesNoncurrent100.0100.0

us-gaap:DepositsOnFlightEquipment



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302010-12-31
Value590533463396325439429505560494531526541545489551617771775905778555511431360446550443341369385331266262208202
Percentage of DepositsOnFlightEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:DerivativeAssets

us-gaap:CommodityContract, us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value1117794545835221081020161984510574171516292744657861131116131
Percentage of DerivativeAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestRateSwap, us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value03248101514139889
Percentage of DerivativeAssets0.027.328.657.188.9250.027.824.137.140.980.0100.090.0

us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency

us-gaap:CommodityContract, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value1117794545835221081020161984510574171516292744657861131116131
Percentage of DerivativeAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestRateSwap, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value03248101514139889
Percentage of DerivativeAssets0.027.328.657.188.9250.027.824.137.140.980.0100.090.0

us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:DerivativeLiabilities

us-gaap:InterestRateSwap, us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value-3110-14-10-87-3-4-68-1112125202222182219211917191817192033
Percentage of DerivativeLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency

us-gaap:InterestRateSwap, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value-3110-14-10-87-3-4-68-1112125202222182219211917191817192033
Percentage of DerivativeLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EmployeeRelatedLiabilitiesCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value316470391371301415334345299418345308281397257239213298218179160232201166146211176140132184163134123163147136116176155
Percentage of EmployeeRelatedLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FlightEquipmentGross



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302010-12-31
Value822885498492841783408221791177887567755975907377713769476398619859455690555753455204516551004993485546774419440543614248411840994113404140583807
Percentage of FlightEquipmentGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:LiabilitiesFairValueDisclosure

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value3110141087348
Percentage of LiabilitiesFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value3110141087348
Percentage of LiabilitiesFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312015-09-302015-06-30
Value516516516516516516516475475475475452302100100
Percentage of LineOfCreditFacilityMaximumBorrowingCapacity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtInstrument, us-gaap:LineOfCreditFacility

alk:CreditFacility1, alk:SecuredByAircraft



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value250250250250250250250250250100100100100100100
Percentage of LineOfCreditFacilityMaximumBorrowingCapacity48.448.448.448.448.452.652.652.655.333.10.00.00.00.00.0

alk:CreditFacility2, alk:SecuredByAircraft



Period End2020-03-312019-09-302019-06-302019-03-312018-07-302018-06-302018-03-312017-09-302017-06-30
Value11611611611611675757552
Percentage of LineOfCreditFacilityMaximumBorrowingCapacity22.522.522.522.50.015.815.815.811.5

alk:CreditFacility3, alk:SecuredByOther



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-12-31
Value150150150150150150150150150100100
Percentage of LineOfCreditFacilityMaximumBorrowingCapacity29.129.129.129.129.131.631.631.633.233.10.0

us-gaap:LongTermDebtAndCapitalLeaseObligations



Period End2020-03-312019-12-31
Value12031264
Percentage of LongTermDebtAndCapitalLeaseObligations100.0100.0

us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent



Period End2020-03-312019-12-31
Value1059235
Percentage of LongTermDebtAndCapitalLeaseObligationsCurrent100.0100.0

us-gaap:LongTermDebtPercentageBearingFixedInterestRate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value0.0330.0330.0340.0360.0380.0410.0410.0410.0420.0420.0430.0430.0440.0440.0460.0570.0570.0570.0570.0570.0570.0570.0570.0570.0570.0570.0570.0570.0580.0580.0580.0590.0590.0580.06
Percentage of LongTermDebtPercentageBearingFixedInterestRate100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LongTermDebtPercentageBearingVariableInterestRate



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312010-12-31
Value0.0240.0290.0320.0360.0380.0390.0340.0350.0330.0280.0260.0260.0250.0240.0230.0210.0210.0180.0180.0170.0160.0160.0160.0160.0170.0170.0170.0180.0180.020.020.020.020.0190.018
Percentage of LongTermDebtPercentageBearingVariableInterestRate100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:MarketableSecuritiesCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value13141300138213831221113112231466135114271596172415271252140815261486125511701147126111101309148813301250140413721170113011581150109310381198108698211181027
Percentage of MarketableSecuritiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueByMeasurementBasis

us-gaap:NotesPayableFairValueDisclosure

us-gaap:CarryingReportedAmountFairValueDisclosure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value4574755695825156427068418779591024109011161179730474491520540567587614633659678703721746844
Percentage of NotesPayableFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:EstimateOfFairValueFairValueDisclosure



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value4874835845955186417008318719591034110511301199759509529557575612640666687713733762781807915
Percentage of NotesPayableFairValueDisclosure106.6101.7102.6102.2100.699.899.298.899.3100.0101.0101.4101.3101.7104.0107.4107.7107.1106.5107.9109.0108.5108.5108.2108.1108.4108.3108.2108.4

us-gaap:OperatingLeaseLiabilityCurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value2662692682732750
Percentage of OperatingLeaseLiabilityCurrent100.0100.0100.0100.0100.00.0

us-gaap:OperatingLeaseLiabilityNoncurrent



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value137514391376142414430
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0100.0100.0100.00.0

us-gaap:OtherAssets



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value3937405439473989401023442342234623312310229522932280224665
Percentage of OtherAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PreferredStockParOrStatedValuePerShare



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-03-312010-12-312009-12-31
Value0.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.010.011.01.01.01.01.01.01.01.01.01.01.01.01.0
Percentage of PreferredStockParOrStatedValuePerShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PropertyPlantAndEquipmentOther



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302010-12-31
Value134313061272123811971363132212911287122211871158113911031021994967955936915899896883867853838857867862855848857851762730647
Percentage of PropertyPlantAndEquipmentOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RestrictedCashAndCashEquivalentsAtCarryingValue



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value111210101066000
Percentage of RestrictedCashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:TreasuryStockShares



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302012-12-312012-09-302012-06-302012-03-312011-12-312011-03-312010-12-312009-12-31
Value98887777766655554310000000000002110
Percentage of TreasuryStockShares100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0100.0100.0100.0100.0

us-gaap:OtherCommitments

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary

alk:AircraftMaintenanceDeposits



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value662927242452525252636363
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:Capacity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value1841841791791791791741741741731659494949292106683031141414141919191918181818
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary3066.73066.7617.2663.0745.8745.8334.6334.6334.6332.7261.9149.2149.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CapitalAdditions



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value27311941031071083023043031932732602752773343373203273723723723934304304294293383293293221818181
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary450.0516.7669.0381.5445.8450.0580.8584.6582.7371.2433.3412.7436.50.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherCommitments

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary

alk:AircraftMaintenanceDeposits



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value24265451484864646464686868
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:Capacity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value179179174174174174166166166165158909090868699644242323232321818181818181818
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary745.8688.5322.2341.2362.5362.5259.4259.4259.4257.8232.4132.4132.40.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CapitalAdditions



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value20020633330330530755856256226835233833735464564838139042842842843038238235434127922122120449484732
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary833.3792.3616.7594.1635.4639.6871.9878.1878.1418.8517.6497.1495.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherCommitments

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary

alk:AircraftMaintenanceDeposits



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value55627373656565656565616161
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:Capacity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value166166145145145145138138151151118808080787890585856444444443838381817171717
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary301.8267.7198.6198.6223.1223.1212.3212.3232.3232.3193.4131.1131.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CapitalAdditions



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value556487504542519517514558560816956836876848931931516549601604585496331423369338448414403332351333307289
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary1010.9785.5690.4742.5798.5795.4790.8858.5861.51255.41567.21370.51436.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherCommitments

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary

alk:AircraftMaintenanceDeposits



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value47516362595968686868656565
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:Capacity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value174174166166166166145145159159151858585818194606160323232323131311817171717
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary370.2341.2263.5267.7281.4281.4213.2213.2233.8233.8232.3130.8130.80.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CapitalAdditions



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value340347475553553556525515514377806758730694724725472444544548530471359359304289328259259254215194170158
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary723.4680.4754.0891.9937.3942.4772.1757.4755.9554.41240.01166.21123.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherCommitments

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount

alk:AircraftMaintenanceDeposits



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value172220245255251265303319347349362376391
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:Capacity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value1691172817631798183318671861189519551856186310631083110111001116130087147548513514716017212313314298102107116125
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount983.1785.5719.6705.1730.3704.5614.2594.0563.4531.8514.6282.7277.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CapitalAdditions



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value156516281653178819342016241725472690275429103017333734603177334624832633264627352950295926232780272828382960288429662972784812889856
Percentage of UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount909.9740.0674.7701.2770.5760.8797.7798.4775.2789.1803.9802.4853.50.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherCommitments

us-gaap:UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears

alk:AircraftMaintenanceDeposits



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value221098838383839909090
Percentage of UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:Capacity



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value8808801065106510651065120512051205107912506766766767467458585542452450000888826262626
Percentage of UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears44000.044000.010650.011833.313312.513312.53171.13171.13171.12766.71388.9751.1751.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CapitalAdditions



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-31
Value262636323333140141141145355362361361397400392418650650650653104410371034103414501456146114883636362
Percentage of UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears1300.01300.0360.0355.6412.5412.5368.4371.1371.1371.8394.4402.2401.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherCommitments

us-gaap:UnrecordedUnconditionalPurchaseObligationDueInRemainderOfFiscalYear

alk:AircraftMaintenanceDeposits



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value38163347163260152944
Percentage of UnrecordedUnconditionalPurchaseObligationDueInRemainderOfFiscalYear100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:Capacity



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value108346910433671002138581734533913253891928
Percentage of UnrecordedUnconditionalPurchaseObligationDueInRemainderOfFiscalYear284.2212.5209.1221.3206.2209.4166.7140.0131.0131.80.00.00.00.00.00.00.00.00.00.0

us-gaap:CapitalAdditions



Period End2020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value4161112554173784676101684637581463054025113338577149238117205293
Percentage of UnrecordedUnconditionalPurchaseObligationDueInRemainderOfFiscalYear1094.7693.8772.7887.22362.51459.41016.71120.01596.61722.70.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AircraftType

us-gaap:UnrecordedUnconditionalPurchaseObligationMinimumQuantityRequired

alk:E175



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302016-09-302016-06-30
Value3.03.03.05.07.07.017.018.022.023.023.033.033.0
Percentage of UnrecordedUnconditionalPurchaseObligationMinimumQuantityRequired100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

srt:B737



Period End2020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value32.032.032.032.032.036.038.041.0
Percentage of UnrecordedUnconditionalPurchaseObligationMinimumQuantityRequired1066.71066.71066.7640.0457.1514.3223.5227.8

Line plots across dimensions of each concept

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService, us-gaap:ContractWithCustomerSalesChannel


us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService, us-gaap:ContractWithCustomerSalesChannel


us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService, us-gaap:ContractWithCustomerSalesChannel


us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ContractWithCustomerSalesChannel


us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService


us-gaap:Revenues us-gaap:StatementBusinessSegments


us-gaap:CostsAndExpenses us-gaap:StatementBusinessSegments


us-gaap:NonoperatingIncomeExpense us-gaap:StatementBusinessSegments


us-gaap:Assets us-gaap:StatementBusinessSegments


us-gaap:StockholdersEquity us-gaap:StatementEquityComponents


us-gaap:LongTermDebt us-gaap:DebtInstrument


us-gaap:StockholdersEquity us-gaap:StatementEquityComponents