UAL


Line plots across dimensions of each concept
Line plots across concepts
Tables

Table of contents



us-gaap:CommonStockValue
us-gaap:StatementEquityComponents
us-gaap:CommonStockSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareBasicAndDiluted

us-gaap:AllocatedShareBasedCompensationExpense

us-gaap:ComprehensiveIncomeNetOfTax
dei:LegalEntity

us-gaap:CostsAndExpenses
dei:LegalEntity

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
dei:LegalEntity

us-gaap:IncomeTaxExpenseBenefit
dei:LegalEntity

us-gaap:NetIncomeLoss
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted

us-gaap:NonoperatingIncomeExpense
dei:LegalEntity

us-gaap:OperatingIncomeLoss
dei:LegalEntity

us-gaap:OtherComprehensiveIncomeLossNetOfTax
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:OtherNonoperatingIncomeExpense
dei:LegalEntity

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
dei:LegalEntity
dei:LegalEntity, us-gaap:ProductOrService
us-gaap:AirlineDestinations
us-gaap:ProductOrService
us-gaap:ProductOrService, us-gaap:TypeOfArrangement

us-gaap:Revenues

us-gaap:Assets
dei:LegalEntity

us-gaap:LiabilitiesAndStockholdersEquity
dei:LegalEntity

us-gaap:StockholdersEquity
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:AssetsCurrent
dei:LegalEntity

us-gaap:CashAndCashEquivalentsAtCarryingValue
dei:LegalEntity

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents
dei:LegalEntity

us-gaap:ShortTermInvestments
dei:LegalEntity

us-gaap:ReceivablesNetCurrent
dei:LegalEntity

us-gaap:PrepaidExpenseAndOtherAssetsCurrent
dei:LegalEntity

us-gaap:Goodwill
dei:LegalEntity

us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill
us-gaap:IndefiniteLivedIntangibleAssetsByMajorClass

us-gaap:IntangibleAssetsNetExcludingGoodwill
dei:LegalEntity

us-gaap:DeferredTaxAssetsLiabilitiesNet
dei:LegalEntity

us-gaap:OperatingLeaseRightOfUseAsset
dei:LegalEntity

us-gaap:OtherAssetsNoncurrent
dei:LegalEntity
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:EquitySecuritiesFvNi
us-gaap:FairValueByMeasurementFrequency
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:AccountsPayableCurrent
dei:LegalEntity
us-gaap:ProductOrService
us-gaap:ContractWithCustomerLiabilityCurrent

us-gaap:LiabilitiesCurrent
dei:LegalEntity

us-gaap:LongTermDebtCurrent
dei:LegalEntity

us-gaap:OperatingLeaseLiabilityCurrent
dei:LegalEntity

us-gaap:OtherLiabilitiesCurrent
dei:LegalEntity
dei:LegalEntity
us-gaap:LongTermDebt
us-gaap:DebtInstrument
us-gaap:FairValueByMeasurementBasis

us-gaap:LongTermDebtNoncurrent
dei:LegalEntity

us-gaap:DeferredIncomeTaxLiabilitiesNet
dei:LegalEntity
us-gaap:RetirementPlanType
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent

us-gaap:OtherLiabilitiesNoncurrent
dei:LegalEntity

us-gaap:OperatingLeaseLiabilityNoncurrent
dei:LegalEntity

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:OperatingLeaseLiability

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

us-gaap:StockholdersEquity
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:CommonStockValue

us-gaap:AdditionalPaidInCapitalCommonStock
dei:LegalEntity

us-gaap:RetainedEarningsAccumulatedDeficit
dei:LegalEntity

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax
dei:LegalEntity

us-gaap:TreasuryStockValue

us-gaap:StockIssuedDuringPeriodValueNewIssues
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect
dei:LegalEntity

us-gaap:DepreciationDepletionAndAmortization
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInOperatingActivities
dei:LegalEntity

us-gaap:NetIncomeLoss
dei:LegalEntity
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:StatementEquityComponents

us-gaap:NetCashProvidedByUsedInInvestingActivities
dei:LegalEntity

us-gaap:PaymentsToAcquireProductiveAssets
dei:LegalEntity

us-gaap:NetCashProvidedByUsedInFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromIssuanceOfLongTermDebt
dei:LegalEntity
dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
dei:LegalEntity, us-gaap:LongtermDebtType
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType
us-gaap:LongtermDebtType

us-gaap:RepaymentsOfLongTermDebt
dei:LegalEntity

us-gaap:PaymentsForRepurchaseOfCommonStock

us-gaap:EffectiveIncomeTaxRateContinuingOperations

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod

us-gaap:DeferredTaxAssetsNet
dei:LegalEntity

us-gaap:UnrecognizedTaxBenefits

us-gaap:DeferredTaxAssetsValuationAllowance
dei:LegalEntity
dei:LegalEntity
ual:CapitalContributionsToParent
dei:LegalEntity, us-gaap:StatementEquityComponents
dei:LegalEntity, us-gaap:CreditFacility, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType, us-gaap:VariableRate
ual:DebtInstrumentVariableRateFloor
us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType, us-gaap:VariableRate
us-gaap:RetirementPlanType
ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSettlementExcludingRestructuring
us-gaap:RetirementPlanType
ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSettlementRestructuring

ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSettlementRestructuringAndSpecialAndContractualTerminationBenefits
us-gaap:RestructuringCostAndReserve, us-gaap:RestructuringPlan
ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSpecialAndContractualTerminationBenefits
us-gaap:RetirementPlanType
us-gaap:ProductOrService
ual:FrequentFlyerMileageMilesAwardedInPeriod

ual:GainLossOnContractTerminationAndNaturalDisaster

ual:GainLossOnDebtExtinguishmentAndModificationNonoperating

ual:GainLossOnFinancialInstrumentsNonOperating
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

ual:GainLossOnNetCharges

ual:GainLossOnSaleOfOtherAssetsAndOtherMiscellaneousCharges

ual:IncomeTaxExpenseBenefitSpecialCharges

ual:LeaseConversionsFromOperatingLeaseRecordedPropertyPlantAndEquipment
dei:LegalEntity
us-gaap:ProductOrService
ual:NonTravelMilesRedemptionFrequentFlyerDeferredRevenue

ual:NumberOfEmployeesNotifiedOfPlansForWorkforceReduction

ual:OtherComprehensiveIncomeInvestmentsAndOtherNetOfTax
dei:LegalEntity
dei:LegalEntity
ual:PaymentsOfDividendsToParentCompany
dei:LegalEntity
ual:PercentageOfEmployeesRepresentedByLaborOrganizations

ual:ProceedsFromGovernmentAssistance
us-gaap:SubsequentEventType

ual:ProceedsFromGovernmentAssistanceGrants
us-gaap:RestructuringCostAndReserve, us-gaap:RestructuringPlan
ual:RestructuringAndRelatedCostNumberOfEmployeesVoluntarilySeparated
ual:EmployeeClassification, us-gaap:RestructuringCostAndReserve, us-gaap:RestructuringPlan
ual:RestructuringProgramsOneTimeContributionPerEmployee

ual:SpecialChargesAndLossesOnFinancialInstrumentsNonOperatingBeforeTax

ual:SpecialChargesAndLossesOnFinancialInstrumentsOperatingAndNonoperatingBeforeTax

ual:SpecialItemsNetOfIncomeTaxBenefits
us-gaap:ProductOrService
ual:TravelMilesRedemptionFrequentFlyerDeferredRevenue

ual:UnusualOrInfrequentEventPayrollTaxesDeferredUnderCARESAct

ual:UnusualOrInfrequentItemsPercentOfCapacityCut
us-gaap:StatementScenario

us-gaap:AdjustmentsToAdditionalPaidInCapitalWarrantIssued
us-gaap:ClassOfWarrantOrRight
us-gaap:StatementEquityComponents

us-gaap:AircraftMaintenanceMaterialsAndRepairs
dei:LegalEntity

us-gaap:AircraftRental
dei:LegalEntity

us-gaap:AirlineCapacityPurchaseArrangements
dei:LegalEntity

us-gaap:AssetImpairmentCharges
us-gaap:ProductOrService
us-gaap:ContractWithCustomerLiabilityRevenueRecognized
dei:LegalEntity, us-gaap:CreditFacility, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType, us-gaap:VariableRate
us-gaap:DebtInstrumentBasisSpreadOnVariableRate1
us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType, us-gaap:VariableRate
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanBenefitObligationPeriodIncreaseDecrease
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanInterestCost
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanOtherCosts
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanServiceCost

us-gaap:DepreciationAndAmortization
dei:LegalEntity
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquitySecuritiesFvNiUnrealizedGainLoss

us-gaap:FinanceLeasePrincipalPayments
dei:LegalEntity

us-gaap:FuelCosts
dei:LegalEntity
us-gaap:IndefiniteLivedIntangibleAssetsByMajorClass
us-gaap:ImpairmentOfIntangibleAssetsExcludingGoodwill

us-gaap:IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance

us-gaap:InterestCostsCapitalizedAdjustment
dei:LegalEntity

us-gaap:InterestCostsIncurred
dei:LegalEntity

us-gaap:InvestmentIncomeInterest
dei:LegalEntity

us-gaap:LaborAndRelatedExpense
dei:LegalEntity

us-gaap:LandingFeesAndOtherRentals
dei:LegalEntity

us-gaap:NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1
dei:LegalEntity
us-gaap:StatementEquityComponents
us-gaap:OciBeforeReclassificationsBeforeTaxAttributableToParent

us-gaap:OciBeforeReclassificationsNetOfTaxAttributableToParent
us-gaap:PropertyPlantAndEquipmentByType
us-gaap:OperatingLeaseImpairmentLoss

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
dei:LegalEntity

us-gaap:OtherCostAndExpenseOperating
dei:LegalEntity

us-gaap:OtherSignificantNoncashTransactionValueOfConsiderationReceived1
dei:LegalEntity

us-gaap:PaymentsForProceedsFromOtherInvestingActivities
dei:LegalEntity

us-gaap:PaymentsOfDebtIssuanceCosts
dei:LegalEntity

us-gaap:PaymentsToAcquireShortTermInvestments
dei:LegalEntity

us-gaap:PostemploymentBenefitsPeriodExpense

us-gaap:ProceedsFromIssuanceOfCommonStock
us-gaap:SubsidiarySaleOfStock

us-gaap:ProceedsFromIssuanceOfUnsecuredDebt

us-gaap:ProceedsFromIssuanceOfWarrants

us-gaap:ProceedsFromIssuanceOrSaleOfEquity
dei:LegalEntity
dei:LegalEntity, us-gaap:CreditFacility, us-gaap:LongtermDebtType
us-gaap:ProceedsFromLinesOfCredit
dei:LegalEntity, us-gaap:CreditFacility, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType, us-gaap:VariableRate

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities
dei:LegalEntity

us-gaap:ProceedsFromSaleMaturityAndCollectionsOfInvestments
dei:LegalEntity

us-gaap:ProvisionForLoanLossesExpensed
us-gaap:CounterpartyName, us-gaap:FinancingReceivableRecordedInvestmentByClassOfFinancingReceivable
us-gaap:StatementEquityComponents
us-gaap:ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent

us-gaap:ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent

us-gaap:ReclassificationFromAociCurrentPeriodTax

us-gaap:RestructuringSettlementAndImpairmentProvisions
dei:LegalEntity

us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability
dei:LegalEntity

us-gaap:SellingExpense
dei:LegalEntity
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodSharesNewIssues
us-gaap:SubsidiarySaleOfStock
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodSharesShareBasedCompensation

us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation
us-gaap:StatementEquityComponents
dei:LegalEntity
us-gaap:StockholdersEquityOther
dei:LegalEntity, us-gaap:StatementEquityComponents
us-gaap:AircraftType
us-gaap:TangibleAssetImpairmentCharges
us-gaap:StatementEquityComponents
us-gaap:TreasuryStockSharesAcquired

us-gaap:TreasuryStockValueAcquiredCostMethod
us-gaap:StatementEquityComponents

us-gaap:UnrealizedGainLossOnDerivatives

us-gaap:UnrealizedGainLossOnInvestments
dei:LegalEntity

us-gaap:UnusualOrInfrequentItemGainGross

dei:EntityCommonStockSharesOutstanding
dei:LegalEntity
dei:LegalEntity
dei:EntityNumberOfEmployees

ual:CapitalLossCarryforwardsValuationAllowance
us-gaap:ClassOfWarrantOrRight
ual:ClassofWarrantorRightNumberOfSecuritiesCalledbyWarrantsOrRightsIssuableUnderAgreement
us-gaap:ClassOfWarrantOrRight, us-gaap:SubsequentEventType
us-gaap:ProductOrService
ual:ContractWithCustomerLiabilityAdvanceTicketSales

ual:ContractWithCustomerLiabilityCurrentAdvanceTicketSales
dei:LegalEntity

ual:ContractWithCustomerLiabilityCurrentFrequentFlyer
dei:LegalEntity

ual:ContractWithCustomerLiabilityNoncurrentFrequentFlyer
dei:LegalEntity
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
ual:DebtCovenantRequiredLiquidity
us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType
ual:DebtInstrumentIncreaseInPrincipalAmountAsAPercentOfTreasuryDisbursements
us-gaap:DebtInstrument
ual:DeferredGrantIncome

ual:DeferredTaxAssetLeasingArrangements
dei:LegalEntity

ual:DeferredTaxAssetsSaleLeasebackLiability
dei:LegalEntity
us-gaap:RetirementPlanType
ual:DefinedBenefitPlanEffectOf50BasisPointDecreaseInDiscountRateOnAccumulatedPostretirementBenefitObligation

ual:ElectronicTravelCertificatesAndFutureFlightCreditsPercentOfCreditsWithExpirationDatesBeyond12Months
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
ual:EquitySecuritiesOwnershipPercentage
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:FinancialInstrument
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
ual:EquitySecuritiesWithoutReadilyDeterminableFairValueOwnershipInterest
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:FinancialInstrument

ual:ExciseTaxRefundsReceivable

ual:FinancialLiabilitiesSaleLeasebackTransactionsNoncurrent
dei:LegalEntity

ual:GovernmentAssistanceDeferredCreditCurrent
dei:LegalEntity

ual:LesseeOperatingAndFinanceLeaseNotYetCommencedAmount
dei:LegalEntity
ual:LongTermDebtMaturityAfterYearFour

ual:NumberOfAircraftInSaleLeasebackTransactionIncludedInFlightEquipment
us-gaap:IncomeTaxAuthority
ual:OperatingLossCarryforwardsAndTaxCreditCarryforwardsValuationAllowance
dei:LegalEntity, us-gaap:IncomeTaxAuthority
ual:OperatingLossCarryforwardsTaxEffectedAmount

ual:OtherLiabilitiesAndDeferredCreditsNoncurrent
dei:LegalEntity

ual:PayrollSupportProgramFundingProvided
ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms
us-gaap:SubsequentEventType
us-gaap:StatementScenario, ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms
ual:PayrollSupportProgramFundingProvidedAmountsExpectedToBeReceived
us-gaap:StatementScenario, ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms, us-gaap:DebtInstrument
ual:PayrollSupportProgramFundingProvidedAmountsExpectedToBeReceivedThroughLoans
us-gaap:StatementScenario, ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms
ual:PayrollSupportProgramFundingProvidedAmountsReceivedThroughDirectGrants
us-gaap:SubsequentEventType
ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms, us-gaap:DebtInstrument, us-gaap:LongtermDebtType
ual:PayrollSupportProgramFundingProvidedAmountsReceivedThroughLoans
us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType

ual:RestrictedCashAmountsToBeUsedForBorrowingFeesPrincipalAndInterest
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
ual:RestrictedCashCurrentFairValueDisclosure
us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
ual:RestrictedCashNoncurrentFairValueDisclosure
us-gaap:FairValueByMeasurementFrequency
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
ual:UnrecordedUnconditionalPurchaseObligationToBePaidAfterYearFour
dei:LegalEntity, us-gaap:ProductOrService, us-gaap:RecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:AccountsPayableRelatedPartiesCurrent

us-gaap:AirlineRelatedInventoryNet
dei:LegalEntity

us-gaap:AirlineRelatedInventoryValuationReserves
dei:LegalEntity

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent
dei:LegalEntity
us-gaap:StatementEquityComponents
us-gaap:AociBeforeTaxAttributableToParent

us-gaap:AociTaxAttributableToParent

us-gaap:CapitalizedComputerSoftwareGross
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:CashAndCashEquivalentsFairValueDisclosure
us-gaap:FairValueByMeasurementFrequency

us-gaap:CashCollateralForBorrowedSecurities
us-gaap:ClassOfWarrantOrRight
us-gaap:ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
us-gaap:ClassOfWarrantOrRight, us-gaap:SubsequentEventType
us-gaap:StatementScenario, ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms
us-gaap:ClassOfWarrantOrRight
us-gaap:ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights

us-gaap:ClassOfWarrantOrRightOutstanding
us-gaap:ClassOfWarrantOrRight

us-gaap:CommonStockCapitalSharesReservedForFutureIssuance
us-gaap:ProductOrService
us-gaap:ContractWithCustomerLiability

us-gaap:ContractualObligation
us-gaap:DebtInstrument

us-gaap:ContractualObligationDueAfterFifthYear

us-gaap:ContractualObligationDueInFifthYear

us-gaap:ContractualObligationDueInFourthYear

us-gaap:ContractualObligationDueInNextTwelveMonths

us-gaap:ContractualObligationDueInSecondYear

us-gaap:ContractualObligationDueInThirdYear

us-gaap:DebtInstrumentCarryingAmount

us-gaap:DebtInstrumentUnamortizedDiscount

us-gaap:DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet
us-gaap:AwardType
us-gaap:DeferredCompensationSharebasedArrangementsLiabilityCurrentAndNoncurrent

us-gaap:DeferredIncomeTaxAssetsNet
dei:LegalEntity

us-gaap:DeferredIncomeTaxLiabilities
dei:LegalEntity

us-gaap:DeferredTaxAssetsDeferredIncome
dei:LegalEntity

us-gaap:DeferredTaxAssetsOperatingLossCarryforwards
dei:LegalEntity
dei:LegalEntity, us-gaap:IncomeTaxAuthority
us-gaap:DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration

us-gaap:DeferredTaxAssetsOther
dei:LegalEntity

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits
dei:LegalEntity

us-gaap:DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets
dei:LegalEntity

us-gaap:DeferredTaxLiabilitiesLeasingArrangements
dei:LegalEntity

us-gaap:DeferredTaxLiabilitiesPropertyPlantAndEquipment
dei:LegalEntity

us-gaap:DefinedBenefitPensionPlanLiabilitiesNoncurrent
dei:LegalEntity
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax

us-gaap:DefinedBenefitPlanAmountsRecognizedInBalanceSheet
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanBenefitObligation
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanFundedStatusOfPlan
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation
dei:LegalEntity, us-gaap:Range, us-gaap:DefinedBenefitPlanByPlanAssetCategories
us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1

us-gaap:DepositsOnFlightEquipment
dei:LegalEntity

us-gaap:EmployeeRelatedLiabilitiesCurrent
dei:LegalEntity

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
us-gaap:AwardType
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquityMethodInvestmentOwnershipPercentage

us-gaap:EquityMethodInvestments
us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName
us-gaap:EquitySecuritiesWithoutReadilyDeterminableFairValueAmount

us-gaap:FinanceLeaseLiability

us-gaap:FinanceLeaseLiabilityCurrent
dei:LegalEntity

us-gaap:FinanceLeaseLiabilityNoncurrent
dei:LegalEntity

us-gaap:FinanceLeaseLiabilityPaymentsDue

us-gaap:FinanceLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:FinanceLeaseLiabilityPaymentsDueNextTwelveMonths

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFive

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFour

us-gaap:FinanceLeaseLiabilityPaymentsDueYearThree

us-gaap:FinanceLeaseLiabilityPaymentsDueYearTwo

us-gaap:FinanceLeaseLiabilityUndiscountedExcessAmount

us-gaap:FinanceLeaseWeightedAverageDiscountRatePercent

us-gaap:FinancingReceivableAllowanceForCreditLosses
dei:LegalEntity

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization
dei:LegalEntity
us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFive

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFour

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearThree

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo

us-gaap:FiniteLivedIntangibleAssetsGross
us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:FlightEquipmentGross
dei:LegalEntity
us-gaap:DebtInstrument, us-gaap:GuaranteeObligationsByNature
us-gaap:GuaranteeObligationsCurrentCarryingValue
us-gaap:DebtInstrument
us-gaap:GuaranteeObligationsMaximumExposure
us-gaap:DebtInstrument, us-gaap:GuaranteeObligationsByNature

us-gaap:InvestmentsAndOtherNoncurrentAssets
dei:LegalEntity

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths
dei:LegalEntity, us-gaap:CreditFacility, us-gaap:LongtermDebtType
us-gaap:LineOfCredit
dei:LegalEntity, us-gaap:GuaranteeObligationsByNature
dei:LegalEntity, us-gaap:CreditFacility, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType
us-gaap:LineOfCreditFacilityMaximumBorrowingCapacity
us-gaap:CreditFacility, us-gaap:DebtInstrument
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
dei:LegalEntity, us-gaap:CreditFacility, us-gaap:LongtermDebtType
us-gaap:LineOfCreditFacilityRemainingBorrowingCapacity
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis
us-gaap:LongTermDebtFairValue
us-gaap:FairValueByMeasurementBasis
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
dei:LegalEntity
us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear
us-gaap:LossContingenciesByNatureOfContingency
us-gaap:LossContingencyEstimateOfPossibleLoss

us-gaap:NotesAndLoansReceivableNetNoncurrent
dei:LegalEntity

us-gaap:NotesReceivableFairValueDisclosure
dei:LegalEntity, us-gaap:CounterpartyName, us-gaap:FinancingReceivableRecordedInvestmentByClassOfFinancingReceivable
us-gaap:NotesReceivableGross
us-gaap:CounterpartyName
us-gaap:NotesReceivableNet

us-gaap:OperatingLeaseWeightedAverageDiscountRatePercent
dei:LegalEntity, ual:NetOperatingLossCarryforwardByExpiration, us-gaap:IncomeTaxAuthority
us-gaap:OperatingLossCarryforwards
dei:LegalEntity, us-gaap:IncomeTaxAuthority
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:OtherLongTermInvestments
us-gaap:FairValueByMeasurementFrequency

us-gaap:OtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent
dei:LegalEntity
us-gaap:RetirementPlanType
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities

us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization
dei:LegalEntity

us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization
dei:LegalEntity

us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization
dei:LegalEntity

us-gaap:PropertyPlantAndEquipmentOther
dei:LegalEntity
dei:LegalEntity
us-gaap:ReceivableFromShareholdersOrAffiliatesForIssuanceOfCapitalStock

us-gaap:ReceivableWithImputedInterestFaceAmount

us-gaap:RestrictedCashAndCashEquivalentsAtCarryingValue
dei:LegalEntity

us-gaap:RestrictedCashAndCashEquivalentsNoncurrent
dei:LegalEntity

us-gaap:RestrictedCashCurrent
dei:LegalEntity

us-gaap:RestrictedCashNoncurrent
dei:LegalEntity
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice
us-gaap:SubsidiarySaleOfStock
us-gaap:SharesIssuedPricePerShare
us-gaap:IncomeTaxAuthority
us-gaap:TaxCreditCarryforwardAmount

us-gaap:UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFifthAnniversary

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFirstAnniversary
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnSecondAnniversary
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceOnThirdAnniversary
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:UnrecordedUnconditionalPurchaseObligationDueAfterFiveYears
us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased
us-gaap:UnrecordedUnconditionalPurchaseObligationDueInRemainderOfFiscalYear
dei:LegalEntity, us-gaap:ValuationAllowancesAndReservesType
us-gaap:ValuationAllowancesAndReservesBalance
us-gaap:ClassOfWarrantOrRight
us-gaap:WarrantsAndRightsOutstanding

Plots across concepts


IncomeStatement
Income Loss From Continuing Operations 
Before Income Taxes Extraordinary Items Noncontrolling Interest
Expenses
Income Tax Expense Benefit
Balance Sheet
Short Term Investments
Assets
Operating Lease Right Of Use Asset
Current Assets
Prepaid Expense And Other Assets Current
NonCurrent Assets
Deferred Income Tax Assets Net
Liabilities
Operating Lease Liability
Current Liabilities
Operating Lease Liability Current
Noncurrent Liabilities
Deferred Income Tax Liabilities Net
Stockholders Equity
Accumulated Other Comprehensive Income Loss Net Of Tax
CashFlow
Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInOperatingActivities
Net Income Loss
NetCashProvidedByUsedInInvestingActivities
Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInFinancingActivities
Proceeds From Payments For Other Financing Activities
Shares
Weighted Average Number Of Diluted Shares Outstanding
OperatingLeaseLiability
Operating Lease Liability Current
NonoperatingIncomeExpense
Nonoperating Income Expense
LesseeOperatingLeaseLiabilityPaymentsDue
Lessee Operating Lease Liability Payments Due Year Two
AccountsReceivable
Allowance For Doubtful Accounts Receivable Current

Tables

  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:CommonStockValue ███▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁██████████████▁▁▁▁▁▁▁▁▁▁4.04.04.03.03.03.03.03.03.03.03.03.03.03.03.03.03.03.03.04.04.04.04.04.04.04.04.04.04.04.04.04.04.03.03.03.03.03.03.03.03.03.03.0NANANA
 us-gaap:CommonStockSharesOutstanding us-gaap:StatementEquityComponents us-gaap:CommonStock██▇▅▅▁▁▂▂▃▃▃▃▄▅323.6323.6311.8291.0291.0247.3251.2253.6257.7264.3269.9272.5273.0279.4287.0NANANA314.6NANANA364.6NANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding 323.6NANA291.0280.7248.5NA256.4261.6268.3NA273.6275.6284.9NA300.6307.7314.6NA321.0331.0355.0NA376.0380.0384.0NA392.0396.0368.0NA395.0394.0NANA332.0393.0NANA392.0400.0NANA235.0235.0NA
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic █▁323.6316.6NA291.0280.7248.5NA255.3260.8267.0NA272.4274.7283.9NA299.8306.9313.7NA320.0331.0354.0NA375.0380.0382.0NA370.0373.0368.0NA357.0341.0NANA331.0331.0NANA330.0330.0NANA168.0168.0NA
us-gaap:EarningsPerShareBasic -1.34NA-6.39-6.33-5.79-6.862.544.014.031.091.713.072.490.521.992.122.670.311.263.021.780.882.2412.833.141.330.082.492.11-1.660.391.061.37-1.26-1.870.021.02-1.36-0.421.971.63-0.65-1.012.31.62-0.49
us-gaap:EarningsPerShareDiluted -1.34NA-6.390000000000001-6.33-5.79NA2.533.994.021.091.73.062.480.521.992.122.660.311.263.011.780.882.2412.823.141.320.072.372.01-1.660.370.981.21-1.26-1.870.020.89-1.36-0.421.691.39-0.65-1.011.751.29-0.49
us-gaap:EarningsPerShareBasicAndDiluted NA-4.29NANANA-6.86NANANA1.09NANANA0.52NANANA0.32NANANANANANANANANANANA-1.66NANANA-1.26NANANA-1.36NANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
 Cost Ratio dei:LegalEntity ual:UnitedAirLinesInc▄▂▂▂▁▆███▇▇██▆▇▇▇▆▆▇▇▆▆▇▇▆▇▇▇▆▇▇▇▆▄▄▄▃▄▄▄▃▃▄▄5471.03221.03412.02489.01475.07979.010888.011380.011402.09589.010491.011003.010777.09032.09451.09899.010000.08420.09054.09913.09396.08195.09036.010306.09914.08608.09313.010563.010329.08696.09331.010230.010003.08723.05055.05656.05475.04775.05052.05857.05570.04676.04911.05419.05163.0NA
 EBT Margin dei:LegalEntity ual:UnitedAirLinesInc▄▂▂▂▁▆███▇▇██▆▇▇▇▆▆▇▇▆▆▇▇▆▇▇▇▆▇▇▇▆5471.03221.03412.02489.01475.07979.010888.011380.011402.09589.010491.011003.010777.09032.09451.09899.010000.08420.09054.09913.09396.08195.09036.010306.09914.08608.09313.010563.010329.08696.09331.010230.010003.08723.0NANANANANANANANANANANANA
 Operating Margin dei:LegalEntity ual:UnitedAirLinesInc▄▂▂▂▁▆███▇▇██▆▇▇▇▆▆▇▇▆▆▇▇▆▇▇▇▆▇▇▇▆▄▄▄▃▄▄▄▃▃▄▄5471.03221.03412.02489.01475.07979.010888.011380.011402.09589.010491.011003.010777.09032.09451.09899.010000.08420.09054.09913.09396.08195.09036.010306.09914.08608.09313.010563.010329.08696.09331.010230.010003.08723.05055.05656.05475.04775.05052.05857.05570.04676.04911.05419.05163.0NA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:AllocatedShareBasedCompensationExpense ▆▄▃▄▃▂▃▄▂▂▃▃▃▂▁▂▄▃▄▃▁▂▂▁▂▂▄▃▂▃▃▃▂▃▂▂▂▂▂▂▂▂█▂▁69.034.025.041.024.018.030.033.021.016.028.029.027.017.07.010.033.023.034.023.03.010.018.07.016.017.045.023.014.032.028.032.013.027.013.018.011.015.014.013.014.013.087.09.08.0NA
us-gaap:ComprehensiveIncomeNetOfTax ▃▂▁▂▁▁▄▅▄▃▄▄▄▃▄▄▄▃▄▄▄▄▄█▅▄▂▄▄▃▄▄▄▃▂▃▃▃▃▄▃▃-422.0-1344.0-2027.0-1591.0-2115.0-1757.0427.01327.01038.0302.0742.0849.0696.0180.0375.0657.0810.089.0366.0901.0631.0367.0926.04694.01358.0610.0-1439.0723.0798.0-637.01241.0455.0927.0-398.0-1347.0186.0120.0-311.0-510.0368.024.0156.0NANANANA
 us-gaap:ComprehensiveIncomeNetOfTax dei:LegalEntity ual:UnitedAirLinesInc▃▂▁▂▁▁▄▅▄▃▄▄▄▃▄▄▄▃▄▄▄▄▄█▅▄▂▄▄▃▄▄▄▃▂▃▃▃▃▃▃▃-422.0-1344.0-2026.0-1591.0-2114.0-1757.0428.01327.01038.0303.0743.0850.0696.0180.0392.0657.0810.090.0366.0901.0631.0368.0925.04654.01359.0611.0-1475.0732.0777.0-607.01255.0454.0942.0-336.0-716.0-26.0-203.0-347.0-187.0231.0-80.0100.0NANANANA
us-gaap:CostsAndExpenses ▄▃▃▂▁▇███▇███▇▇▇▇▆▆▆▆▅▆▆▆▆▇▇▇▇▇█▇▇▇█▇▇▇▇▇▆▆▃▃▂5741.04602.05547.04104.03112.08951.010027.09907.09930.09094.09839.09800.09616.08756.08709.08786.08601.08142.08047.08289.08336.07546.07955.08407.08469.07867.08688.09372.09423.09045.09094.09720.09231.08985.09167.09709.09364.08873.08883.09236.09001.08168.08450.04876.04720.04165.0
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest ▄▂▁▁▂▁▇██▆▆▇▇▅▆▇▇▅▇█▇▆▇█▇▆▅▇▇▄▅▆▆▄-564.0-1751.0-2373.0-2332.0-2003.0-2114.0844.01349.01354.0367.0556.01061.0857.0184.0600.0980.01274.0145.0884.01510.0931.0494.0905.01606.01197.0511.023.0920.0791.0-606.0112.0382.0471.0-426.0NANANANANANANANANANANANA
 us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest dei:LegalEntity ual:UnitedAirLinesInc▄▂▁▁▂▁▇██▆▆▇▇▅▆▇▇▅▇█▇▆▇█▇▆▅▇▇▄▅▆▆▅-564.0-1751.0-2372.0-2332.0-2003.0-2113.0844.01350.01354.0368.0557.01062.0856.0185.0601.0980.01274.0146.0886.01510.0931.0495.0906.01607.01197.0511.0-13.0929.0771.0-577.0133.0382.0486.0-364.0NANANANANANANANANANANANA
us-gaap:IncomeTaxExpenseBenefit ▇▆▆▆▆▆▇██▇▇▇▇▇▇██▇███▇▇▁▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇-130.0-394.0-476.0-491.0-376.0-410.0203.0325.0302.075.094.0225.0173.037.020.0343.0456.049.0487.0545.0343.0181.082.0-3210.04.03.0-6.0-4.02.03.0-7.03.02.0-9.0-9.09.01.01.0-2.07.04.02.0NA0.0-2.01.0
 us-gaap:IncomeTaxExpenseBenefit dei:LegalEntity ual:UnitedAirLinesInc▇▆▆▆▆▆▇██▇▇▇▇▇▇██▇███▇▇▁▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇▇-130.0-394.0-476.0-491.0-377.0-409.0202.0326.0302.075.094.0225.0172.038.04.0343.0456.049.0489.0545.0343.0181.083.0-3169.04.02.0-5.0-4.02.03.0-21.04.02.0-2.01.07.0-1.02.01.02.0NANA-11.00.0-2.0NA
us-gaap:NetIncomeLoss ▃▂▁▁▁▁▄▄▄▃▃▄▄▃▄▄▄▃▃▄▄▃▄█▄▄▃▄▄▂▃▃▃▃▂▃▃▃▃▄▄▃▃▃▃▃-434.0-1357.0-1897.0-1841.0-1627.0-1704.0641.01024.01052.0292.0462.0836.0684.0147.0580.0637.0818.096.0397.0965.0588.0313.0823.04816.01193.0508.028.0924.0789.0-609.0140.0379.0469.0-417.0-620.06.0339.0-448.0-138.0653.0538.0-213.0-325.0387.0273.0-82.0
 us-gaap:NetIncomeLoss dei:LegalEntity ual:UnitedAirLinesInc▃▂▁▁▁▁▄▄▄▃▃▄▄▃▄▄▄▃▃▄▄▃▄█▄▄▃▄▄▂▃▃▃▃▂▃▃▃▃▃▃▃▃▃▃-434.0-1357.0-1896.0-1841.0-1626.0-1704.0642.01024.01052.0293.0463.0837.0684.0147.0597.0637.0818.097.0397.0965.0588.0314.0823.04776.01193.0509.0-8.0933.0769.0-580.0154.0378.0484.0-362.0-567.0-127.0-71.0-423.0-255.0415.0281.0-160.0-207.0399.0281.0NA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:StatementEquityComponents ual:UnitedAirLinesInc,us-gaap:RetainedEarnings▄▂▁▁▂▁▇██▆▇▇▇▆-434.0-1357.0-1896.0-1841.0-1626.0-1704.0642.01024.01052.0293.0469.0834.0683.0145.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents us-gaap:RetainedEarnings▄▂▁▁▂▁▇██▆▇▇▇▆-434.0-1357.0-1897.0-1841.0-1627.0-1704.0641.01024.01052.0292.0468.0833.0683.0145.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic ▃▂▁▁▁▁▄▄▄▃▃▄▄▃▄▄▄▃▃▄▄▃▄█▄▄▃▄▄▂▃▃▃-434.0-1357.0-1897.0-1841.0-1627.0-1704.0641.01024.01052.0292.0462.0836.0684.0147.0580.0637.0818.096.0397.0965.0588.0313.0823.04816.01193.0508.030.0923.0788.0-609.0139.0378.0468.0NA-620.06.0338.0-448.0-138.0651.0536.0-213.0-325.0387.0273.0NA
us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted -434.0NANANA-1627.0NANANANANANANANANANANANANA397.0965.0588.0313.0823.04816.01193.0508.021.0929.0794.0-609.0145.0387.0479.0NA-620.06.0349.0NA-162.0663.0558.0NA-370.0413.0303.0NA
us-gaap:NonoperatingIncomeExpense ▆▆▇▄▆▁█▇▇▇█▇▆█▇▇▇▇▇▇▇▇▇▆▇▇▄▆▇▇▇▇▆▇▇▇▇▇▇▆▆▇▇▇▇▇-294.0-370.0-238.0-717.0-366.0-1142.0-17.0-124.0-118.0-128.0-96.0-142.0-304.0-92.0-129.0-112.0-125.0-133.0-121.0-114.0-129.0-155.0-176.0-293.0-248.0-230.0-602.0-271.0-115.0-257.0-123.0-126.0-299.0-162.0-167.0-185.0-235.0-176.0-191.0-275.0-266.0-245.0-245.0-154.0-170.0-158.0
 us-gaap:NonoperatingIncomeExpense dei:LegalEntity ual:UnitedAirLinesInc▆▆▇▄▆▁█▇▇▇█▇▆█▇▇▇▇▇▇▇▇▇▆▇▇▄▇▇▇▇▇▆▇█▇▇▇▇▇▇▇▇▇▇-295.0-370.0-238.0-717.0-367.0-1141.0-17.0-124.0-118.0-128.0-96.0-141.0-305.0-92.0-129.0-112.0-126.0-132.0-121.0-114.0-129.0-155.0-175.0-293.0-249.0-230.0-639.0-257.0-135.0-236.0-105.0-128.0-287.0-102.0-87.0-119.0-156.0-113.0-117.0-162.0-156.0-168.0-165.0-150.0-164.0NA
us-gaap:OperatingIncomeLoss ▄▂▁▂▂▃▆▇▇▆▆▇▇▅▆▇▇▅▆█▇▆▇█▇▆▆▇▆▄▅▆▆▄▄▅▆▄▅▆▆▅▅▆▅▅-270.0-1381.0-2135.0-1615.0-1637.0-972.0861.01473.01472.0495.0652.01203.01161.0276.0729.01092.01399.0278.01005.01624.01060.0649.01081.01899.01445.0741.0625.01191.0906.0-349.0235.0508.0770.0-264.0-465.0200.0575.0-271.045.0935.0808.034.0-82.0541.0441.076.0
 us-gaap:OperatingIncomeLoss dei:LegalEntity ual:UnitedAirLinesInc▄▂▁▂▂▃▆▇▇▆▆▇▇▅▆▇▇▅▆█▇▆▇█▇▆▆▇▆▄▅▆▆▄▄▅▅▄▄▆▅▅▅▆▅-269.0-1381.0-2134.0-1615.0-1636.0-972.0861.01474.01472.0496.0653.01203.01161.0277.0730.01092.01400.0278.01007.01624.01060.0650.01081.01900.01446.0741.0626.01186.0906.0-341.0238.0510.0773.0-262.0-479.0-1.084.0-308.0-137.0579.0437.08.0-53.0549.0443.0NA
us-gaap:OtherComprehensiveIncomeLossNetOfTax ▅▅▅▆▄▅▄▆▅▅▆▅▅▅▄▅▅▅▅▅▅▅▅▅▅▅▁▄▅▅█▅▆▅▃▅▄▅12.013.0-130.0250.0-488.0-53.0-214.0303.0-14.010.0280.013.012.033.0-205.020.0-8.0-7.0-31.0-64.043.054.0103.0-122.0165.0102.0-1467.0-201.09.0-28.01101.076.0458.019.0-727.0180.0-219.0137.0NANANANANANANANA
us-gaap:OtherNonoperatingIncomeExpense ▇▇▇▄▆▁▇████▇▆███▇▇▇██▇▇▆▇▇▃▇█▇██▆███▇██▇▇▇▇███-49.0-19.0-10.0-411.0-207.0-699.0-59.09.014.09.043.0-1.0-166.048.06.015.0-1.0-17.0-8.02.05.0-18.0-31.0-147.0-100.0-74.0-443.0-106.054.0-89.051.052.0-123.023.019.04.0-38.027.014.0-64.0-29.0-1.0-2.016.03.024.0
 us-gaap:OtherNonoperatingIncomeExpense dei:LegalEntity ual:UnitedAirLinesInc▇▇▇▄▅▁▇▇▇▇█▇▆█▇▇▇▇▇▇▇▇▇▆▆▇▃▆█▇██▆█▇▇▇▇▇▇▇▇▇▇▇-50.0-19.0-10.0-411.0-208.0-698.0-59.09.014.09.043.00.0-167.048.06.015.0-2.0-16.0-8.02.05.0-18.0-29.0-147.0-101.0-74.0-478.0-91.036.0-66.071.050.0-117.085.06.0-1.0-25.018.010.0-35.0-3.0-5.0-2.015.04.0NA
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax ▄▂▂▂▁▆███▇▇██▆▇▇▇▆▆▇▇▆▆▇▇▆▇▇▇▆▇▇▇▆▆▇▇▆▆▇▇▆▆▄▄▃5471.03221.03412.02489.01475.07979.010888.011380.011402.09589.010491.011003.010777.09032.09451.09899.010008.08426.09052.09913.09396.08195.09036.010306.09914.08608.09313.010563.010329.08696.09329.010228.010001.08721.08702.09909.09939.08602.08928.010171.09809.08202.08464.05417.05161.04241.0
us-gaap:Revenues ▄▂▂▂▁▆███▇▇██▆▇▇▇▆▆▇▇▆▆▇▇▆▇▇▇▆▇▇▇▆▆▇▇▆▆▇▇▆▆▄▄▃5471.03221.03412.02489.01475.07979.010888.011380.011402.09589.010491.011003.010777.09032.09438.09878.010000.08420.09052.09913.09396.08195.09036.010306.09914.08608.09313.010563.010329.08696.09329.010228.010001.08721.08702.09909.09939.08602.08928.010171.09809.08202.08464.05417.05161.04241.0
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:Assets █▆▆▆▅▄▄▄▄▄▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▂▂▂71049.061662.059548.061189.054901.053055.052611.052199.052150.050639.044792.044837.044691.044018.042326.042565.042307.041445.040140.040327.040476.040373.040861.041869.039367.039091.037353.038011.038447.037185.036812.037260.037468.036842.037628.037905.038694.038199.037988.039054.039694.040552.039598.0NANANA
us-gaap:LiabilitiesAndStockholdersEquity █▆▆▆▅▄▄▄▄▄▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▂▂▂71049.061662.059548.061189.054901.053055.052611.052199.052150.050639.044792.044837.044691.044018.042326.042565.042307.041445.040140.040327.040476.040373.040861.041869.039367.039091.037353.038011.038447.037185.036812.037260.037468.036842.037628.037905.038694.038199.037988.039054.039694.040552.039598.0NANANA
us-gaap:StockholdersEquity ▄▄▅▅▆▇██▇▇▇▇▆▆▆▆▆▆▆▆▆▆▆▆▃▃▂▃▃▃▃▂▂▁▁▂▂▂▂▂▂▂▂4904.05206.05960.07003.08517.09418.011531.011301.010320.09802.09995.09469.08639.08336.08806.08970.08854.08449.08659.08439.07784.07840.08966.08555.04122.03008.02396.03864.03347.02579.02984.01728.01217.094.0481.01827.01635.01510.01806.02312.01942.01912.01727.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:AssetsCurrent █▅▄▅▂▁▁▂▂▁▁▂▂▁▁▁▁▁▁▁▁▁▁▂▂▂▁▂▂▂▂▂▂▂▂▂▃▃▃▃▃▃▃24673.016019.014800.016476.010041.07905.08194.08533.08910.07608.07194.08671.08881.08287.07113.07877.08248.07724.07309.07970.07844.07224.07828.010097.08793.09509.08138.09225.09619.08788.08702.09389.09621.09148.010049.010774.011708.011261.010997.011986.012391.013148.012045.0NANANA
us-gaap:CashAndCashEquivalentsAtCarryingValue █▅▅▅▃▂▁▂▂▁▁▁▂▁▁▁▁▁▁▁▁▁▂▂▁▂▁▂▂▂▂▂▂▂▂▂▃▂▃▃▃▃▃▂▂▂20838.012666.011269.013150.06505.03442.02762.02959.03221.01848.01694.02621.02884.02404.01482.01870.02371.02164.02179.02630.02483.01795.03006.03427.02796.03352.02002.03117.03424.03009.03220.03935.04143.03538.04770.05129.06086.05606.06246.06984.07519.08165.08069.04938.04906.03516.0
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents █▅▅▅▃▂▁▂▂▁▁▁▁▁▁▁▁21308.013138.011742.013398.06612.03548.02868.03063.03326.01951.01799.02726.02991.02510.01591.01979.02501.0NA2303.0NANANA3212.0NANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:ShortTermInvestments ▁▁▂▂▃▆▇▇▇▇▇█▇▇██▇▇▇▇▇▇▇▇▇▇███▇▆▆▆▆▆▅▅▆▅▅▄▃▂230.0309.0414.0552.0958.01779.02182.02167.02223.02219.02256.02314.02187.02071.02316.02458.02278.02215.02249.02226.02202.02177.02190.02172.02189.02256.02382.02397.02372.02015.01901.01801.01821.01852.01773.01551.01618.01667.01516.01373.01060.0722.0611.0NANANA
us-gaap:ReceivablesNetCurrent ▅▄▃▃▁▁▄▅▅▅▃▅▆▅▃▅▄▄▃▄▄▅▃▄▄▄▃▄▅▅▄▅▅▅▃▆▆▆▄▅▆█▅1793.01389.01295.01171.0857.0792.01364.01617.01762.01789.01346.01752.01840.01760.01340.01603.01499.01429.01176.01481.01450.01581.01128.01513.01471.01471.01146.01559.01665.01609.01503.01693.01732.01679.01338.01862.01818.01908.01358.01713.01863.02357.01613.0NANANA
us-gaap:PrepaidExpenseAndOtherAssetsCurrent ▃▁▂▂▄▄▄▃▃▄▅▆▆▇▆▆█▆▄▄▅▅▃▄▅▄▃▄▄▄▃▃▄▄▅▄▄▄▂▂▄646.0483.0635.0566.0766.0822.0814.0725.0708.0780.0913.0973.01028.01128.01051.01009.01218.01016.0832.0791.0911.0912.0740.0819.0881.0826.0730.0838.0839.0845.0704.0700.0790.0845.0865.0837.0797.0783.0607.0595.0773.0NA658.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:Goodwill ████▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁4527.04527.04527.04527.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.04523.0NANANA
us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill NANA2577.0NANANA2693.0NANANA2783.0NANANA3095.0NANANA3095.0NANANA3509.0NANANA3542.0NANANA3565.0NANANA3584.0NANANA3614.0NANANANANANANA
 us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill us-gaap:IndefiniteLivedIntangibleAssetsByMajorClass ual:AirportSlotsAndGatesIndefiniteLivedNANA560.0NANANA546.0NANANA546.0NANANA536.0NANANA536.0NANANA942.0NANANA956.0NANANANANANANANANANANANANANANANANANANA
 us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill us-gaap:IndefiniteLivedIntangibleAssetsByMajorClass ual:RouteAuthoritiesNANA1020.0NANANA1150.0NANANA1240.0NANANA1562.0NANANA1562.0NANANA1570.0NANANA1589.0NANANA1605.0NANANA1606.0NANANA1606.0NANANANANANANA
 us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill us-gaap:IndefiniteLivedIntangibleAssetsByMajorClass us-gaap:UseRightsNANANA1100.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:IntangibleAssetsNetExcludingGoodwill ▁▁▁▁▁▁▂▂▂▂▂▃▃▃▃▃▄▄▄▄▄▅▅▆▆▆▆▆▆▆▆▇▇▇▇▇▇▇▇████2827.02840.02838.02852.02852.02945.03009.03114.03129.03144.03159.03382.03399.03521.03539.03558.03592.03612.03632.03654.03677.04112.04136.04193.04220.04257.04284.04330.04372.04402.04436.04487.04523.04561.04597.04650.04681.04712.04750.04772.04815.04866.04917.0NANANA
us-gaap:DeferredTaxAssetsLiabilitiesNet NANA131.0NANANANANANANANANANANANANANANA655.0NANANA2037.0NANANA-1000.0NANANA-987.0NANANA-1000.0NANANA-988.0NANANA-994.0NANANA
 us-gaap:DeferredTaxAssetsLiabilitiesNet dei:LegalEntity ual:UnitedAirLinesIncNANA103.0NANANANANANANANANANANANANANANA612.0NANANA1995.0NANANA-1000.0NANANA-987.0NANANA-376.0NANANA-359.0NANANANANANANA
us-gaap:OperatingLeaseRightOfUseAsset ▁▂▂▂▄▅▄▅▅▆█4421.04516.04537.04544.04738.04853.04758.04937.04908.05065.05262.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherAssetsNoncurrent ▇▇▆▆▆▆▇▇▇▇▇▆▆▆▆▆▆▇▇▇▇██▇▇▇▇▇▇▇▇▇▇▇▇▇▇▁▁▁▁▁▁9624.09212.08745.08519.08387.08486.09489.09397.09414.09380.09269.08858.08864.08992.09005.09059.09042.09480.09513.09712.010244.011143.011453.010596.09873.09720.09748.09843.09971.010013.010063.010105.010263.010257.010287.010321.010409.0730.0770.0795.0816.0731.0715.0NANANA
 us-gaap:EquitySecuritiesFvNi us-gaap:FairValueByFairValueHierarchyLevel,us-gaap:FairValueByMeasurementFrequency us-gaap:FairValueInputsLevel1,us-gaap:FairValueMeasurementsRecurring█▄▅▁269.0182.0205.0118.0NA92.0385.0322.0301.0NA249.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:EquitySecuritiesFvNi us-gaap:FairValueByMeasurementFrequency us-gaap:FairValueMeasurementsRecurring█▄▅▂▁269.0182.0205.0118.0101.0NA385.0322.0301.0NA249.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:EquitySecuritiesFvNi us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName ual:Azul▄▃▄▂▁▁█238.0182.0205.0118.0101.092.0385.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:EquitySecuritiesFvNi us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName ual:ClearSecureInc31.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:AccountsPayableCurrent ▄▂▁▂▂▅▆▇█▆▅▆▆▅▄▄▄▄▄▄▄▃▂▃▅▃▂▃▅▅▃▄▄▄▄▄▄▄▃▂▃▂▂2218.01838.01595.01831.01725.02436.02703.02848.03033.02707.02363.02581.02703.02399.02196.02231.02225.02135.02139.02138.02240.02065.01869.02082.02322.02074.01882.02085.02441.02332.02087.02126.02298.02293.02312.02188.02165.02220.01998.01808.01999.01897.01805.0NANANA
 us-gaap:ContractWithCustomerLiabilityCurrent us-gaap:ProductOrService ual:AdvanceTicketSalesNANA3100.03000.0NANANA5515.06126.0NA4381.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LiabilitiesCurrent █▄▂▆▆▆▅▆▆▅▃▃▄▄▂▃▃▂▂▃▄▃▂▃▄▄▂▃▃▃▂▂▃▃▂▃▃▂▁▂▂▄▂18064.014167.012725.015791.016395.016087.014938.015691.016078.015335.013212.013684.014092.014183.012676.013087.013596.012662.012286.013253.013982.013380.012414.013488.013810.013969.012508.012864.013334.013091.012107.012604.012927.012892.012818.013057.013312.012486.011394.011898.012762.013874.012645.0NANANA
us-gaap:LongTermDebtCurrent ▃▃▃██▇▂▂▂▂▂▁▁▃▃▂▂▁▁▁▂▂▂▂▂▃▂▂▂▂▂▁▁▂▃▃▂▂▂▂▂▄▄1881.01783.01911.04584.04454.04055.01407.01243.01255.01201.01230.0910.0887.01655.01565.01516.01436.0716.0849.0969.01272.01295.01224.01312.01047.01700.01313.01340.01168.01178.01368.0957.0909.01079.01812.01704.01349.01013.01186.01201.01389.02319.02411.0NANANA
us-gaap:OperatingLeaseLiabilityCurrent ▁▂▂▂▂▅▅█▃▃▆583.0623.0612.0623.0598.0688.0686.0778.0637.0639.0719.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherLiabilitiesCurrent ▆▄▄█▁▁▁▂▂819.0724.0724.0944.0558.0538.0566.0574.0604.0NA553.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
 us-gaap:LongTermDebt dei:LegalEntity ual:UalAndUnited█▆▆▆▃▃▂▂▂▂▂▂▂▂▂▂▁▁▁34784.028165.027301.027401.018958.017456.014733.014324.014379.014124.013636.013288.013513.013985.013431.013016.012266.012031.010891.0NANANA11042.0NANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LongTermDebt us-gaap:DebtInstrument ual:FloatingRateDebt█▁13400.010400.0NA12300.07600.06000.0NA3400.03400.03400.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LongTermDebt us-gaap:DebtInstrument ual:PassThroughCertificatesNANA12100.0NANANA9600.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:LongTermDebt us-gaap:FairValueByMeasurementBasis us-gaap:CarryingReportedAmountFairValueDisclosure█▆▆▆▃▃▂▂▂▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁34184.027632.026747.026881.018772.017253.014552.014143.014193.013935.013445.013128.013347.013821.013268.012850.012104.011894.010767.010581.010547.010767.010897.011222.010985.011614.011434.011328.011522.011276.011539.011161.011123.0NA12252.0NANANANANANANANANANANA
us-gaap:LongTermDebtNoncurrent █▆▆▅▃▂▂▂▂▂▂▂▂▂▂▂▁▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▂▂▂32303.025849.024836.022297.014318.013198.013145.012900.012938.012734.012215.012218.012460.012166.011703.011334.010668.011178.09918.09612.09275.09472.09673.09910.09938.09914.010121.09988.010354.010098.010171.010204.010214.010182.010440.09592.010128.010408.010496.010873.011101.011115.011434.0NANANA
us-gaap:DeferredIncomeTaxLiabilitiesNet NANANA389.0804.01322.01736.01594.01192.0898.0814.0639.0419.0NA204.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:DeferredIncomeTaxLiabilitiesNet dei:LegalEntity ual:UnitedAirLinesIncNANANA416.0832.01350.01763.01622.01220.0925.0842.0666.0446.0NA231.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent us-gaap:RetirementPlanType us-gaap:OtherPostretirementBenefitPlansDefinedBenefitNANA994.0NANANA789.0NANANA1295.0NANANA1602.0NANANA1581.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent us-gaap:RetirementPlanType us-gaap:PensionPlansDefinedBenefitNANA2460.0NANANA1446.0NANANA1576.0NANANA1921.0NANANA1892.0NANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:OtherLiabilitiesNoncurrent ▁▁▁▁▁▁▁▁▁▅▆▆▆▆▆▆▆▆▆▆▆▆▆▆▇██▁▁▁▁▁▁▁▁▁▁▁▁▁▁▂▂1350.01298.01156.01174.01430.01179.01024.0981.0980.07387.08236.08350.08461.08314.08145.08206.08245.08320.08455.08271.08695.08956.09081.09154.010934.011640.011757.01371.01371.01281.01283.01298.01392.01328.01366.01356.01364.01351.01395.01322.01314.02615.02704.0NANANA
us-gaap:OperatingLeaseLiabilityNoncurrent ▁▂▂▁▅▄▂▁▃▅█4920.04985.04986.04943.05113.05060.04946.04941.05034.05145.05276.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo NANA693.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree NANA723.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour NANA704.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive NANA585.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive NANA3979.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:StockholdersEquity ▄▄▅▅▆▇██▇▇▇▇▆▆▆▆▆▆▆▆▆▆▆▆▃▃▂▃▃▃▃▂▂▁▁▂▂▂▂▂▂▂▂4904.05206.05960.07003.08517.09418.011531.011301.010320.09802.09995.09469.08639.08336.08806.08970.08854.08449.08659.08439.07784.07840.08966.08555.04122.03008.02396.03864.03347.02579.02984.01728.01217.094.0481.01827.01635.01510.01806.02312.01942.01912.01727.0NANANA
us-gaap:CommonStockValue ███▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁██████████████▁▁▁▁▁▁▁▁▁▁4.04.04.03.03.03.03.03.03.03.03.03.03.03.03.03.03.03.03.04.04.04.04.04.04.04.04.04.04.04.04.04.04.03.03.03.03.03.03.03.03.03.03.0NANANA
us-gaap:AdditionalPaidInCapitalCommonStock ██▆▄▄▁▁▁▁▁▁▁▁▁▁▂▂▂▂▅▅▅▅▅▅▅▅▅▅▅▄▄▄▄▄▄▃▃▃▃▃▃▃9042.08923.08366.07383.07307.06096.06129.06111.06096.06080.06120.06105.06091.06077.06098.06591.06577.06562.06569.07974.07965.07956.07946.07941.07938.07932.07721.07620.07636.07666.07425.07410.07354.07159.07145.07140.07135.07130.07114.07110.07106.07100.07071.0NANANA
us-gaap:RetainedEarningsAccumulatedDeficit ▄▄▅▆▇▇██▇▇▇▆▆▆▆▆▆▅▅▆▆▅▅▅▃▂▂▂▂▁▁▁▁▁▁▁▁▁▂▂▁▁▁804.01239.02626.04524.06365.07991.09716.09075.08050.06999.06668.06203.05367.04684.04621.04991.04354.03536.03427.05323.04358.03770.03457.02634.0-2182.0-3375.0-3883.0-3911.0-4835.0-5624.0-5015.0-5155.0-5534.0-6003.0-5586.0-4965.0-4972.0-5311.0-4863.0-4725.0-5378.0-5916.0-5703.0NANANA
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax ▂▁▁▂▁▃▃▄▃▃▃▂▂▂▁▃▂▂▂▃▃▃▂▂▃▂▂▇▇▇▇▄▃▂▂▄▄▄▄▅▆█▇-1114.0-1126.0-1139.0-1009.0-1259.0-771.0-718.0-504.0-807.0-793.0-803.0-1089.0-1102.0-1114.0-1147.0-824.0-844.0-836.0-829.0-798.0-734.0-777.0-831.0-934.0-812.0-977.0-1079.0388.0589.0580.0608.0-493.0-569.0-1027.0-1046.0-319.0-499.0-280.0-417.0-45.0242.0756.0387.0NANANA
 us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax dei:LegalEntity ual:UnitedAirLinesInc▂▁▁▂▁▃▃▄▃▃▃▂▂▂▁▃▃▅▃▃▃▃▃▂▃▂▂▇███▄▄▂▅▅▅▆▅▅▆-1114.0-1126.0-1139.0-1009.0-1259.0-771.0-718.0-504.0-807.0-793.0-803.0-1089.0-1102.0-1114.0-1147.0-824.0-844.0-89.0-829.0-798.0-734.0-777.0-831.0-933.0-811.0-977.0-1079.0388.0589.0581.0608.0-493.0-569.0-1027.0-232.0-83.0-184.0-52.0-128.0-196.0-10.0NA91.0NANANA
us-gaap:TreasuryStockValue ██████▇▇▆▅▄▄▄▃▂▄▃▂▂██▆▄▃▂▂▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁3832.03834.03897.03898.03899.03901.03599.03384.03022.02487.01993.01753.01720.01314.0769.01791.01236.0816.0511.04064.03809.03113.01610.01090.0826.0576.0367.0237.047.047.038.038.038.038.035.032.032.032.031.031.031.031.031.0NANANA
us-gaap:StockIssuedDuringPeriodValueNewIssues ▁▄▇▁█0.0532.0968.00.01135.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:StockIssuedDuringPeriodValueNewIssues dei:LegalEntity ual:UnitedAirLinesInc▁█0.0532.0NANA1135.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:StockIssuedDuringPeriodValueNewIssues dei:LegalEntity,us-gaap:StatementEquityComponents ual:UnitedAirLinesInc,us-gaap:ReceivablesFromStockholder▁█0.0532.0NANA1135.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents us-gaap:AdditionalPaidInCapital▁▄▇▁█0.0532.0967.00.01135.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue █▃▁▄▂▂▁▂▁▁▁▁▁▁68.032.017.038.020.022.017.018.017.014.015.016.014.015.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities █▅▁▁▄▄▆▆█▇▆▅█▇▅▅2675.0447.0-2177.0-1889.0-130.063.01181.01103.02710.01915.01084.0905.02466.01709.0789.0577.0NANANANANANANANANANANANA1464.0694.0-334.0237.01148.0393.090.0-238.0959.0124.0265.0385.0753.01005.0106.0445.0874.0482.0
us-gaap:NetCashProvidedByUsedInInvestingActivities ▄▅▆██▂▂▄▄▂▁▄▃▄▄▃-781.0-329.040.0770.0812.0-1572.0-1329.0-795.0-856.0-1580.0-1852.0-886.0-1022.0-695.0-849.0-1276.0NANANANANANANANANANANANA-905.0-427.0-723.0-466.0-402.0-431.0-1152.0-230.0-213.0-362.0-517.0-453.0-509.0-320.03472.0-57.0-19.0-76.0
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity ual:UnitedAirLinesInc▄▅▆██▂▂▄▄▂▁▄▃▄▄▃-781.0-329.040.0770.0812.0-1572.0-1329.0-795.0-856.0-1580.0-1852.0-886.0-1022.0-695.0-849.0-1276.0NANANANANANANANANANANANA-905.0-427.0-723.0-466.0-403.0-431.0-235.0-191.0-134.0-121.0-401.0-134.0-262.0-135.0-75.0-57.0NANA
us-gaap:NetCashProvidedByUsedInFinancingActivities ▇▃▂█▄▃▂▁▁▂▂▂▁▂▂▂6276.01278.0481.07905.02382.02189.0-47.0-571.0-479.0-183.0-159.0-284.0-963.0-95.0-328.0177.0NANANANANANANANANANANANA-144.0-478.0342.021.0-141.0-1194.0703.0-489.0-266.0-402.0-486.0-467.0-890.0-589.0-447.0-356.0535.068.0
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect █▃▁▇▄▃▂▂▃▂▂▂▃▃▂▂8170.01396.0-1656.06786.03064.0680.0-195.0-263.01375.0152.0-927.0-265.0481.0919.0-388.0-522.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:DepreciationDepletionAndAmortization ▁█620.0623.0NANA618.0615.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:NetCashProvidedByUsedInOperatingActivities █▅▁▁▄▄▆▆█▇▆▅█▇▅▅2675.0447.0-2177.0-1889.0-130.063.01181.01103.02710.01915.01084.0905.02466.01709.0789.0577.0NANANANANANANANANANANANA1464.0694.0-334.0237.01148.0393.090.0-238.0959.0124.0265.0385.0753.01005.0106.0445.0874.0482.0
us-gaap:NetIncomeLoss ▃▂▁▁▁▁▄▄▄▃▃▄▄▃▄▄▄▃▃▄▄▃▄█▄▄▃▄▄▂▃▃▃▃▂▃▃▃▃▄▄▃▃▃▃▃-434.0-1357.0-1897.0-1841.0-1627.0-1704.0641.01024.01052.0292.0462.0836.0684.0147.0580.0637.0818.096.0397.0965.0588.0313.0823.04816.01193.0508.028.0924.0789.0-609.0140.0379.0469.0-417.0-620.06.0339.0-448.0-138.0653.0538.0-213.0-325.0387.0273.0-82.0
 us-gaap:NetIncomeLoss dei:LegalEntity ual:UnitedAirLinesInc▃▂▁▁▁▁▄▄▄▃▃▄▄▃▄▄▄▃▃▄▄▃▄█▄▄▃▄▄▂▃▃▃▃▂▃▃▃▃▃▃▃▃▃▃-434.0-1357.0-1896.0-1841.0-1626.0-1704.0642.01024.01052.0293.0463.0837.0684.0147.0597.0637.0818.097.0397.0965.0588.0314.0823.04776.01193.0509.0-8.0933.0769.0-580.0154.0378.0484.0-362.0-567.0-127.0-71.0-423.0-255.0415.0281.0-160.0-207.0399.0281.0NA
 us-gaap:NetIncomeLoss dei:LegalEntity,us-gaap:StatementEquityComponents ual:UnitedAirLinesInc,us-gaap:RetainedEarnings▄▂▁▁▂▁▇██▆▇▇▇▆-434.0-1357.0-1896.0-1841.0-1626.0-1704.0642.01024.01052.0293.0469.0834.0683.0145.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents us-gaap:RetainedEarnings▄▂▁▁▂▁▇██▆▇▇▇▆-434.0-1357.0-1897.0-1841.0-1627.0-1704.0641.01024.01052.0292.0468.0833.0683.0145.0NANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInInvestingActivities ▄▅▆██▂▂▄▄▂▁▄▃▄▄▃-781.0-329.040.0770.0812.0-1572.0-1329.0-795.0-856.0-1580.0-1852.0-886.0-1022.0-695.0-849.0-1276.0NANANANANANANANANANANANA-905.0-427.0-723.0-466.0-402.0-431.0-1152.0-230.0-213.0-362.0-517.0-453.0-509.0-320.03472.0-57.0-19.0-76.0
 us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity ual:UnitedAirLinesInc▄▅▆██▂▂▄▄▂▁▄▃▄▄▃-781.0-329.040.0770.0812.0-1572.0-1329.0-795.0-856.0-1580.0-1852.0-886.0-1022.0-695.0-849.0-1276.0NANANANANANANANANANANANA-905.0-427.0-723.0-466.0-403.0-431.0-235.0-191.0-134.0-121.0-401.0-134.0-262.0-135.0-75.0-57.0NANA
us-gaap:PaymentsToAcquireProductiveAssets ▅▃▂▁▂█▆▅▅▇▇▅▄▅▅▅▅▄▅▄▅▅▄▄▅▃▄▃▄▃▄▄▃▃▆▃▃▃▃▃▃▃▃▂▂▂861.0444.097.0-368.039.01959.01192.0869.0858.01609.01585.0858.0755.0979.01098.01120.01089.0691.0880.0689.0838.0816.0763.0673.01101.0210.0660.0392.0589.0364.0765.0578.0446.0375.01242.0222.0286.0266.0190.0160.0145.0205.0159.088.073.051.0
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
us-gaap:NetCashProvidedByUsedInFinancingActivities ▇▃▂█▄▃▂▁▁▂▂▂▁▂▂▂6276.01278.0481.07905.02382.02189.0-47.0-571.0-479.0-183.0-159.0-284.0-963.0-95.0-328.0177.0NANANANANANANANANANANANA-144.0-478.0342.021.0-141.0-1194.0703.0-489.0-266.0-402.0-486.0-467.0-890.0-589.0-447.0-356.0535.068.0
us-gaap:ProceedsFromIssuanceOfLongTermDebt ▇▂▃█▂▁▁▁▁▁▁▁▁▁▁▂▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▂▁▁▁▁▁▁▁▁▁▁▂9780.01336.03020.011355.01321.0348.0738.0113.0350.0646.0408.024.0612.0696.0646.0980.0384.0755.0298.0435.033.042.0460.0385.0128.0100.0255.0782.0248.0147.0604.0299.0411.0109.01035.00.00.086.010.00.0110.032.091.00.0686.01309.0
us-gaap:RepaymentsOfLongTermDebt █▂█▂▁▁▂▁▁▁▁▁▃▁▁▁▁▁▁▂▁▁▂▁▃▁▂▃▁▂▁▁▂▃▁▂▁▂▂▂▃▂▂▁▁▃3503.0569.03419.0441.0288.0235.0514.0253.0223.0250.0208.0225.01105.0189.0179.0197.0210.0315.0304.0458.0226.0227.0650.0209.01023.0296.0502.01089.0299.0613.0220.0228.0496.01241.0234.0462.0217.0479.0442.0448.0949.0528.0494.0255.070.01204.0
us-gaap:PaymentsForRepurchaseOfCommonStock NANA0.00.00.0353.0214.0369.0549.0513.0225.041.0440.0529.0553.0579.0454.0258.0172.0260.0790.01392.0523.0265.0250.0195.092.0NANANANANANANANANANANANANANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value4000000.04000000.04000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.02000000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Shares Outstanding

us-gaap:CommonStockSharesOutstanding us-gaap:StatementEquityComponents

us-gaap:CommonStockSharesOutstanding

us-gaap:CommonStock


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value323323311291291247251253257264269272273279287314364
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding


Weighted
Period End2021-06-302020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302012-09-302012-06-302011-09-302011-06-302010-09-302010-06-30
Value323291280248256261268273275284300307314321331355376380384392396368395394332393392400235235
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302012-09-302012-06-302011-09-302011-06-302010-09-302010-06-30
Value323316291280248255260267272274283299306313320331354375380382370373368357341331331330330168168
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

us-gaap:EarningsPerShareBasic


Earnings
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-1.34-6.39-6.33-5.79-6.862.544.014.031.091.713.072.490.521.992.122.670.311.263.021.780.882.2412.833.141.330.082.492.11-1.660.391.061.37-1.26-1.870.021.02-1.36-0.421.971.63-0.65-1.012.31.62-0.49
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareDiluted


Earnings
Period End2021-06-302020-12-312020-09-302020-06-302019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-1.34-6.39-6.33-5.792.533.994.021.091.73.062.480.521.992.122.660.311.263.011.780.882.2412.823.141.320.072.372.01-1.660.370.981.21-1.26-1.870.020.89-1.36-0.421.691.39-0.65-1.011.751.29-0.49
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Basic And Diluted

us-gaap:EarningsPerShareBasicAndDiluted

us-gaap:EarningsPerShareBasicAndDiluted


Earnings
Period End2021-03-312020-03-312019-03-312018-03-312017-03-312014-03-312013-03-312012-03-31
Value-4.29-6.861.090.520.32-1.66-1.26-1.36
Percentage of EarningsPerShareBasicAndDiluted100.0100.0100.0100.0100.0100.0100.0100.0

Allocated Share Based Compensation Expense

us-gaap:AllocatedShareBasedCompensationExpense

us-gaap:AllocatedShareBasedCompensationExpense


Allocated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value69342541241830332116282927177.010.0332334233.010.0187.0161745231432283213271318111514131413879.08.0
Percentage of AllocatedShareBasedCompensationExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.31.10.71.61.60.20.30.30.20.20.30.30.30.20.10.10.30.30.40.20.00.10.20.10.20.20.50.20.10.40.30.30.10.30.10.20.10.20.20.10.10.21.00.20.2

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value-422.0-1344.0-2027.0-1591.0-2115.0-1757.0427132710383027428496961803756578108936690163136792646941358610-1439.0723798-637.01241455927-398.0-1347.0186120-311.0-510.036824156
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-7.7-41.7-59.4-63.9-143.4-22.03.911.79.13.17.17.76.52.04.06.68.11.14.09.16.74.510.245.513.77.1-15.56.87.7-7.313.34.49.3-4.6-15.51.91.2-3.6-5.73.60.21.9

us-gaap:ComprehensiveIncomeNetOfTax dei:LegalEntity

ual:UnitedAirLinesInc


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value-422.0-1344.0-2026.0-1591.0-2114.0-1757.0428132710383037438506961803926578109036690163136892546541359611-1475.0732777-607.01255454942-336.0-716.0-26.0-203.0-347.0-187.0231-80.0100
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.2100.0100.0100.3100.1100.1100.0100.0104.5100.0100.0101.1100.0100.0100.0100.399.999.1100.1100.2102.5101.297.495.3101.199.8101.684.453.2-14.0-169.2111.636.762.8-333.364.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-7.7-41.7-59.4-63.9-143.3-22.03.911.79.13.27.17.76.52.04.16.68.11.14.09.16.74.510.245.213.77.1-15.86.97.5-7.013.54.49.4-3.9-8.2-0.3-2.0-4.0-2.12.3-0.81.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc-7.7-41.70.0-63.9-143.3-22.00.011.79.13.20.07.76.52.00.06.68.11.10.09.16.74.50.045.213.77.10.06.97.5-7.00.04.49.4-3.90.0-0.5-3.7-7.30.03.9-1.42.1

Costs And Expenses

us-gaap:CostsAndExpenses

us-gaap:CostsAndExpenses


Costs
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value57414602554741043112895110027990799309094983998009616875687098786860181428047828983367546795584078469786786889372942390459094972092318985916797099364887388839236900181688450487647204165
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax104.9142.9162.6164.9211.0112.292.187.187.194.893.889.189.296.992.188.885.996.688.983.688.792.188.081.685.491.493.388.791.2104.097.595.092.3103.0105.398.094.2103.299.590.891.899.699.890.091.598.2

us-gaap:CostsAndExpenses dei:LegalEntity

ual:UnitedAirLinesInc


Costs
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value5740460255464104311189511002799069930909398389800961687558708878686008142804582898336754579558406846878678687937794239037909397209230898555345657539150835189527851334668496448704720
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.1100.099.9100.0100.0100.0100.060.458.357.657.358.457.157.057.158.799.9100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax104.9142.9162.5164.9210.9112.292.187.087.194.893.889.189.296.992.188.885.996.688.983.688.792.188.081.685.491.493.388.891.2103.997.595.092.3103.063.657.154.259.158.151.952.356.958.689.991.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc104.9142.90.0164.9210.9112.20.087.087.194.80.089.189.296.90.088.886.096.70.083.688.792.10.081.685.491.40.088.891.2103.90.095.092.3103.00.0100.098.5106.50.090.192.299.80.089.991.4

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

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-564.0-1751.0-2373.0-2332.0-2003.0-2114.0844134913543675561061857184600980127414588415109314949051606119751123920791-606.0112382471-426.0
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-10.3-54.4-69.5-93.7-135.8-26.57.811.911.93.85.39.68.02.06.39.912.71.79.815.29.96.010.015.612.15.90.28.77.7-7.01.23.74.7-4.9

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest dei:LegalEntity

ual:UnitedAirLinesInc


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-564.0-1751.0-2372.0-2332.0-2003.0-2113.08441350135436855710628561856019801274146886151093149590616071197511-13.0929771-577.0133382486-364.0
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.1100.0100.3100.2100.199.9100.5100.2100.0100.0100.7100.2100.0100.0100.2100.1100.1100.0100.0-56.5101.097.595.2118.8100.0103.285.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-10.3-54.4-69.5-93.7-135.8-26.57.811.911.93.85.39.77.92.06.49.912.71.79.815.29.96.010.015.612.15.9-0.18.87.5-6.61.43.74.9-4.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc-10.3-54.40.0-93.7-135.8-26.50.011.911.93.80.09.77.92.00.09.912.71.70.015.29.96.00.015.612.15.90.08.87.5-6.60.03.74.9-4.2

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value-130.0-394.0-476.0-491.0-376.0-410.0203325302759422517337203434564948754534318182-3210.04.03.0-6.0-4.02.03.0-7.03.02.0-9.0-9.09.01.01.0-2.07.04.02.00.0-2.01.0
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-2.4-12.2-14.0-19.7-25.5-5.11.92.92.60.80.92.01.60.40.23.54.60.65.45.53.72.20.9-31.10.00.0-0.1-0.00.00.0-0.10.00.0-0.1-0.10.10.00.0-0.00.10.00.00.0-0.00.0

us-gaap:IncomeTaxExpenseBenefit dei:LegalEntity

ual:UnitedAirLinesInc


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302010-12-312010-09-302010-06-30
Value-130.0-394.0-476.0-491.0-377.0-409.02023263027594225172384.03434564948954534318183-3169.04.02.0-5.0-4.02.03.0-21.04.02.0-2.01.07.0-1.02.01.02.0-11.00.0-2.0
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.399.899.5100.3100.0100.0100.0100.099.4102.720.0100.0100.0100.0100.4100.0100.0100.0101.298.7100.066.783.3100.0100.0100.0300.0133.3100.022.2-11.177.8-100.0200.0-50.028.60.00.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-2.4-12.2-14.0-19.7-25.6-5.11.92.92.60.80.92.01.60.40.03.54.60.65.45.53.72.20.9-30.70.00.0-0.1-0.00.00.0-0.20.00.0-0.00.00.1-0.00.00.00.0-0.10.0-0.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc-2.4-12.20.0-19.7-25.6-5.10.02.92.60.80.02.01.60.40.03.54.60.60.05.53.72.20.0-30.70.00.00.0-0.00.00.00.00.00.0-0.00.00.1-0.00.00.00.00.00.0-0.0

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-434.0-1357.0-1897.0-1841.0-1627.0-1704.064110241052292462836684147580637818963979655883138234816119350828924789-609.0140379469-417.0-620.06.0339-448.0-138.0653538-213.0-325.0387273-82.0
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-7.9-42.1-55.6-74.0-110.3-21.45.99.09.23.04.47.66.31.66.16.48.21.14.49.76.33.89.146.712.05.90.38.77.6-7.01.53.74.7-4.8-7.10.13.4-5.2-1.56.45.5-2.6-3.87.15.3-1.9

us-gaap:NetIncomeLoss dei:LegalEntity

ual:UnitedAirLinesInc


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value-434.0-1357.0-1896.0-1841.0-1626.0-1704.0642102410522934638376841475976378189739796558831482347761193509-8.0933769-580.0154378484-362.0-567.0-127.0-71.0-423.0-255.0415281-160.0-207.0399281
Percentage of NetIncomeLoss100.0100.099.9100.099.9100.0100.2100.0100.0100.3100.2100.1100.0100.0102.9100.0100.0101.0100.0100.0100.0100.3100.099.2100.0100.2-28.6101.097.595.2110.099.7103.286.891.5-2116.7-20.994.4184.863.652.275.163.7103.1102.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-7.9-42.1-55.6-74.0-110.2-21.45.99.09.23.14.47.66.31.66.36.48.21.24.49.76.33.89.146.312.05.9-0.18.87.4-6.71.73.74.8-4.2-6.5-1.3-0.7-4.9-2.94.12.9-2.0-2.47.45.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc-7.9-42.10.0-74.0-110.2-21.40.09.09.23.10.07.66.31.60.06.48.21.20.09.76.33.80.046.312.05.90.08.87.4-6.70.03.74.8-4.10.0-2.2-1.3-8.90.07.15.0-3.40.07.45.4

us-gaap:NetIncomeLoss dei:LegalEntity, us-gaap:StatementEquityComponents

ual:UnitedAirLinesInc, us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-434.0-1357.0-1896.0-1841.0-1626.0-1704.064210241052293469834683145
Percentage of NetIncomeLoss100.0100.099.9100.099.9100.0100.2100.0100.0100.3101.599.899.998.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-7.9-42.1-55.6-74.0-110.2-21.45.99.09.23.14.57.66.31.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-434.0-1357.0-1897.0-1841.0-1627.0-1704.064110241052292468833683145
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0101.399.699.998.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-7.9-42.1-55.6-74.0-110.3-21.45.99.09.23.04.57.66.31.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Income Loss Available To Common Stockholders Basic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic

us-gaap:NetIncomeLossAvailableToCommonStockholdersBasic


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value-434.0-1357.0-1897.0-1841.0-1627.0-1704.064110241052292462836684147580637818963979655883138234816119350830923788-609.0139378468-620.06.0338-448.0-138.0651536-213.0-325.0387273
Percentage of NetIncomeLossAvailableToCommonStockholdersBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-7.9-42.1-55.6-74.0-110.3-21.45.99.09.23.04.47.66.31.66.16.48.21.14.49.76.33.89.146.712.05.90.38.77.6-7.01.53.74.7-7.10.13.4-5.2-1.56.45.5-2.6-3.87.15.3

Net Income Loss Available To Common Stockholders Diluted

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted

us-gaap:NetIncomeLossAvailableToCommonStockholdersDiluted


Net
Period End2021-06-302020-06-302016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-312012-09-302012-06-302011-12-312011-09-302011-06-302010-12-312010-09-302010-06-30
Value-434.0-1627.03979655883138234816119350821929794-609.0145387479-620.06.0349-162.0663558-370.0413303
Percentage of NetIncomeLossAvailableToCommonStockholdersDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-7.9-110.34.49.76.33.89.146.712.05.90.28.87.7-7.01.63.84.8-7.10.13.5-1.86.55.7-4.47.65.9

Nonoperating Income Expense

us-gaap:NonoperatingIncomeExpense

us-gaap:NonoperatingIncomeExpense


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-294.0-370.0-238.0-717.0-366.0-1142.0-17.0-124.0-118.0-128.0-96.0-142.0-304.0-92.0-129.0-112.0-125.0-133.0-121.0-114.0-129.0-155.0-176.0-293.0-248.0-230.0-602.0-271.0-115.0-257.0-123.0-126.0-299.0-162.0-167.0-185.0-235.0-176.0-191.0-275.0-266.0-245.0-245.0-154.0-170.0-158.0
Percentage of NonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-5.4-11.5-7.0-28.8-24.8-14.3-0.2-1.1-1.0-1.3-0.9-1.3-2.8-1.0-1.4-1.1-1.2-1.6-1.3-1.2-1.4-1.9-1.9-2.8-2.5-2.7-6.5-2.6-1.1-3.0-1.3-1.2-3.0-1.9-1.9-1.9-2.4-2.0-2.1-2.7-2.7-3.0-2.9-2.8-3.3-3.7

us-gaap:NonoperatingIncomeExpense dei:LegalEntity

ual:UnitedAirLinesInc


Nonoperating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value-295.0-370.0-238.0-717.0-367.0-1141.0-17.0-124.0-118.0-128.0-96.0-141.0-305.0-92.0-129.0-112.0-126.0-132.0-121.0-114.0-129.0-155.0-175.0-293.0-249.0-230.0-639.0-257.0-135.0-236.0-105.0-128.0-287.0-102.0-87.0-119.0-156.0-113.0-117.0-162.0-156.0-168.0-165.0-150.0-164.0
Percentage of NonoperatingIncomeExpense100.3100.0100.0100.0100.399.9100.0100.0100.0100.0100.099.3100.3100.0100.0100.0100.899.2100.0100.0100.0100.099.4100.0100.4100.0106.194.8117.491.885.4101.696.063.052.164.366.464.261.358.958.668.667.397.496.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-5.4-11.5-7.0-28.8-24.9-14.3-0.2-1.1-1.0-1.3-0.9-1.3-2.8-1.0-1.4-1.1-1.3-1.6-1.3-1.2-1.4-1.9-1.9-2.8-2.5-2.7-6.9-2.4-1.3-2.7-1.1-1.3-2.9-1.2-1.0-1.2-1.6-1.3-1.3-1.6-1.6-2.0-1.9-2.8-3.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc-5.4-11.50.0-28.8-24.9-14.30.0-1.1-1.0-1.30.0-1.3-2.8-1.00.0-1.1-1.3-1.60.0-1.2-1.4-1.90.0-2.8-2.5-2.70.0-2.4-1.3-2.70.0-1.3-2.9-1.20.0-2.1-2.8-2.40.0-2.8-2.8-3.60.0-2.8-3.2

Operating Income Loss

us-gaap:OperatingIncomeLoss

us-gaap:OperatingIncomeLoss


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-270.0-1381.0-2135.0-1615.0-1637.0-972.08611473147249565212031161276729109213992781005162410606491081189914457416251191906-349.0235508770-264.0-465.0200575-271.04593580834-82.054144176
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-4.9-42.9-62.6-64.9-111.0-12.27.912.912.95.26.210.910.83.17.711.014.03.311.116.411.37.912.018.414.68.66.711.38.8-4.02.55.07.7-3.0-5.32.05.8-3.20.59.28.20.4-1.010.08.51.8

us-gaap:OperatingIncomeLoss dei:LegalEntity

ual:UnitedAirLinesInc


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value-269.0-1381.0-2134.0-1615.0-1636.0-972.08611474147249665312031161277730109214002781007162410606501081190014467416261186906-341.0238510773-262.0-479.0-1.084-308.0-137.05794378.0-53.0549443
Percentage of OperatingIncomeLoss99.6100.0100.0100.099.9100.0100.0100.1100.0100.2100.2100.0100.0100.4100.1100.0100.1100.0100.2100.0100.0100.2100.0100.1100.1100.0100.299.6100.097.7101.3100.4100.499.2103.0-0.514.6113.7-304.461.954.123.564.6101.5100.5
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-4.9-42.9-62.5-64.9-110.9-12.27.913.012.95.26.210.910.83.17.711.014.03.311.116.411.37.912.018.414.68.66.711.28.8-3.92.65.07.7-3.0-5.5-0.00.8-3.6-1.55.74.50.1-0.610.18.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc-4.9-42.90.0-64.9-110.9-12.20.013.012.95.20.010.910.83.10.011.014.03.30.016.411.37.90.018.414.68.60.011.28.8-3.90.05.07.7-3.00.0-0.01.5-6.50.09.97.80.20.010.18.6

Other Comprehensive Income Loss Net Of Tax

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value1213-130.0250-488.0-53.0-214.0303-14.010.0280131233-205.020-8.0-7.0-31.0-64.04354103-122.0165102-1467.0-201.09.0-28.011017645819-727.0180-219.0137
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.4-3.810.0-33.1-0.7-2.02.7-0.10.12.70.10.10.4-2.20.2-0.1-0.1-0.3-0.60.50.71.1-1.21.71.2-15.8-1.90.1-0.311.80.74.60.2-8.41.8-2.21.6

us-gaap:OtherComprehensiveIncomeLossNetOfTax dei:LegalEntity

ual:UnitedAirLinesInc


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value1213-130.0250-488.0-53.0-214.0303-14.010.0280131233-205.020-8.0-7.0-31.0-64.04354102-122.0166102-1467.0-201.08.0-27.011017645826-727.0181-220.0138
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.0100.0100.6100.0100.0100.088.996.4100.0100.0100.0136.8100.0100.6100.5100.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.4-3.810.0-33.1-0.7-2.02.7-0.10.12.70.10.10.4-2.20.2-0.1-0.1-0.3-0.60.50.71.1-1.21.71.2-15.8-1.90.1-0.311.80.74.60.3-8.41.8-2.21.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc0.20.40.010.0-33.1-0.70.02.7-0.10.10.00.10.10.40.00.2-0.1-0.10.0-0.60.50.70.0-1.21.71.20.0-1.90.1-0.30.00.74.60.30.03.2-4.02.9

us-gaap:OtherComprehensiveIncomeLossNetOfTax dei:LegalEntity, us-gaap:StatementEquityComponents

ual:UnitedAirLinesInc, us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value1213-130.0250-488.0-53.0-214.0303-14.010.02871312
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0102.5100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.4-3.810.0-33.1-0.7-2.02.7-0.10.12.70.10.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value1213-130.0250-488.0-53.0-214.0303-14.010.02801312-205.020-8.0-7.0-31.0-64.04354103-122.0165
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax0.20.4-3.810.0-33.1-0.7-2.02.7-0.10.12.70.10.1-2.20.2-0.1-0.1-0.3-0.60.50.71.1-1.21.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:OtherNonoperatingIncomeExpense


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-49.0-19.0-10.0-411.0-207.0-699.0-59.09.0149.043-1.0-166.0486.015-1.0-17.0-8.02.05.0-18.0-31.0-147.0-100.0-74.0-443.0-106.054-89.05152-123.023194.0-38.02714-64.0-29.0-1.0-2.0163.024
Percentage of OtherNonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.9-0.6-0.3-16.5-14.0-8.8-0.50.10.10.10.4-0.0-1.50.50.10.2-0.0-0.2-0.10.00.1-0.2-0.3-1.4-1.0-0.9-4.8-1.00.5-1.00.50.5-1.20.30.20.0-0.40.30.2-0.6-0.3-0.0-0.00.30.10.6

us-gaap:OtherNonoperatingIncomeExpense dei:LegalEntity

ual:UnitedAirLinesInc


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value-50.0-19.0-10.0-411.0-208.0-698.0-59.09.0149.0430.0-167.0486.015-2.0-16.0-8.02.05.0-18.0-29.0-147.0-101.0-74.0-478.0-91.036-66.07150-117.0856.0-1.0-25.01810.0-35.0-3.0-5.0-2.0154.0
Percentage of OtherNonoperatingIncomeExpense102.0100.0100.0100.0100.599.9100.0100.0100.0100.0100.0-0.0100.6100.0100.0100.0200.094.1100.0100.0100.0100.093.5100.0101.0100.0107.985.866.774.2139.296.295.1369.631.6-25.065.866.771.454.710.3500.0100.093.8133.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-0.9-0.6-0.3-16.5-14.1-8.7-0.50.10.10.10.40.0-1.50.50.10.2-0.0-0.2-0.10.00.1-0.2-0.3-1.4-1.0-0.9-5.1-0.90.3-0.80.80.5-1.21.00.1-0.0-0.30.20.1-0.3-0.0-0.1-0.00.30.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc-0.9-0.60.0-16.5-14.1-8.70.00.10.10.10.00.0-1.50.50.00.2-0.0-0.20.00.00.1-0.20.0-1.4-1.0-0.90.0-0.90.3-0.80.00.5-1.21.00.0-0.0-0.50.40.0-0.6-0.1-0.10.00.30.1

Revenue From Contract With Customer Excluding Assessed Tax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value54713221341224891475797910888113801140295891049111003107779032945198991000884269052991393968195903610306991486089313105631032986969329102281000187218702990999398602892810171980982028464541751614241
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax dei:LegalEntity

ual:UnitedAirLinesInc


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value547132213412248914757979108881138011402958910491110031077790329451989910000842090549913939681959036103069914860893131056310329869693311023010003872350555656547547755052585755704676491154195163
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.999.9100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.058.157.155.155.556.657.656.857.058.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.999.9100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.058.157.155.155.556.657.656.857.058.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax dei:LegalEntity, us-gaap:ProductOrService

ual:UnitedAirLinesInc, us-gaap:CargoAndFreight


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value606497560422402264316282295286334296314
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.115.416.417.027.33.32.92.52.63.03.22.72.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.115.416.417.027.33.32.92.52.63.03.22.72.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc us-gaap:CargoAndFreight100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:UnitedAirLinesInc, us-gaap:Passenger


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value436623162410164968170659933104811048687259556101209880
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax79.871.970.666.346.288.591.292.192.091.091.192.091.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax79.871.970.666.346.288.591.292.192.091.091.192.091.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc us-gaap:Passenger100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:UnitedAirLinesInc, us-gaap:ProductAndServiceOther


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value499408442418392650639617621578601587583
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.112.713.016.826.68.15.95.45.46.05.75.35.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.112.713.016.826.68.15.95.45.46.05.75.35.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc us-gaap:ProductAndServiceOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:AirlineDestinations

us-gaap:AtlanticDestination


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value585410427365219121517602103206614581676207319651389
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax10.712.712.514.714.815.216.218.518.115.216.018.818.215.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax10.712.712.514.714.815.216.218.518.115.216.018.818.215.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:AtlanticDestination100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DomesticDestination


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value3767211122361672925507869047094708758756625676266895476
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax68.965.565.567.262.763.663.462.362.261.363.161.562.160.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax68.965.565.567.262.763.663.462.362.261.363.161.562.160.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:DomesticDestination100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LatinAmericaDestination


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value72739238917073880959903943975857829838936
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax13.312.211.46.84.911.08.87.98.310.28.27.57.810.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax13.312.211.46.84.911.08.87.98.310.28.27.57.810.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:LatinAmericaDestination100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PacificDestination


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value39230836028225880612651280130612811333133912851231
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.29.610.611.317.510.111.611.211.513.412.712.211.913.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.29.610.611.317.510.111.611.211.513.412.712.211.913.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:PacificDestination100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService

ual:PassengerAncillaryFees


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value49930821915766476500645636571600572555
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.19.66.46.34.56.04.65.75.66.05.75.25.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.19.66.46.34.56.04.65.75.66.05.75.25.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:PassengerAncillaryFees100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CargoAndFreight


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value606497560422402264316282295286334296314
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.115.416.417.027.33.32.92.52.63.03.22.72.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.115.416.417.027.33.32.92.52.63.03.22.72.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:CargoAndFreight100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Passenger


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value436623162410164968170659933104811048687259556101209880
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax79.871.970.666.346.288.591.292.192.091.091.192.091.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax79.871.970.666.346.288.591.292.192.091.091.192.091.7
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:Passenger100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProductAndServiceOther


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value499408442418392650639617621578601587583
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.112.713.016.826.68.15.95.45.46.05.75.35.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.112.713.016.826.68.15.95.45.46.05.75.35.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductAndServiceOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService, us-gaap:TypeOfArrangement

us-gaap:ProductAndServiceOther, ual:ChaseAndOtherPartnerAgreements


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value449362500378339530500489499473
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax8.211.214.715.223.06.64.64.34.44.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax8.211.214.715.223.06.64.64.34.44.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductAndServiceOther ual:ChaseAndOtherPartnerAgreements100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Revenues

us-gaap:Revenues

us-gaap:Revenues


Revenues
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value54713221341224891475797910888113801140295891049111003107779032943898781000084209052991393968195903610306991486089313105631032986969329102281000187218702990999398602892810171980982028464541751614241
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.999.899.999.9100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Assets

us-gaap:Assets

us-gaap:Assets


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value7104961662595486118954901530555261152199521505063944792448374469144018423264256542307414454014040327404764037340861418693936739091373533801138447371853681237260374683684237628379053869438199379883905439694405523959818684
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets dei:LegalEntity

ual:UnitedAirLinesInc


Assetsdei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value710216163459520611895490153049526055219352144506334478644832446854401342320425584225841395400914032840477403734086141870394093913438108385523893137806372863785338077374782080221605225632177918245188381916019628
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.999.999.9100.0100.0100.0100.0100.0100.1100.1102.0101.4101.3101.7101.3101.6101.6101.755.357.058.357.048.048.248.349.6
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.999.999.9100.0100.0100.0100.0100.0100.1100.1102.0101.4101.3101.7101.3101.6101.6101.755.357.058.357.048.048.248.349.6
Percentage of Assets ual:UnitedAirLinesInc100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value7104961662595486118954901530555261152199521505063944792448374469144018423264256542307414454014040327404764037340861418693936739091373533801138447371853681237260374683684237628379053869438199379883905439694405523959818684
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilitiesAndStockholdersEquity dei:LegalEntity

ual:UnitedAirLinesInc


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value710216163459520611895490153049526055219352144506334478644832446854401342320425584225841395400914032840477403734086141870394093913438108385523893137806372863785338077374782080221605225632177918245188381916019628
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.999.999.9100.0100.0100.0100.0100.0100.1100.1102.0101.4101.3101.7101.3101.6101.6101.755.357.058.357.048.048.248.349.6
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.999.999.9100.0100.0100.0100.0100.0100.1100.1102.0101.4101.3101.7101.3101.6101.6101.755.357.058.357.048.048.248.349.6
Percentage of Assets ual:UnitedAirLinesInc100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value4904520659607003851794181153111301103209802999594698639833688068970885484498659843977847840896685554122300823963864334725792984172812179448118271635151018062312194219121727-2811.0-2321.02610
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.98.410.011.415.517.821.921.619.819.422.321.119.318.920.821.120.920.421.620.919.219.421.920.410.57.76.410.28.76.98.14.63.20.31.34.84.24.04.85.94.94.74.4-15.00.00.0

us-gaap:StockholdersEquity dei:LegalEntity

ual:UnitedAirLinesInc


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-312008-12-31
Value487251755928697284859380114921126310282976399579432860282988768891587998394860684357780783689638552416030462635419935772857322322461787840-3184.0-2470.0-2447.0-2248.0-1904.0-1719.0-1950.0-1977.0-2452.0-2336.0
Percentage of StockholdersEquity99.399.499.599.699.699.699.799.799.699.699.699.699.699.599.699.499.499.399.4100.099.999.9100.0100.0100.9101.3110.0108.7106.9110.8108.0130.0146.8893.6-662.0-135.2-149.7-148.9-105.4-74.4-100.4-114.587.2100.6
Percentage of Assets6.98.410.011.415.517.721.821.619.719.322.221.019.218.920.720.920.820.321.420.919.219.421.920.410.67.87.111.09.37.78.86.04.82.3-8.5-6.5-6.3-5.9-5.0-4.4-4.9-5.0-13.10.0
Percentage of Assets ual:UnitedAirLinesInc6.98.410.011.415.517.721.821.619.719.322.221.019.318.920.720.920.820.321.520.919.219.421.920.410.67.86.910.99.27.68.65.94.72.2-15.3-11.4-10.8-10.3-10.4-9.1-10.2-10.10.00.0

us-gaap:StockholdersEquity dei:LegalEntity, us-gaap:StatementEquityComponents

ual:UnitedAirLinesInc, us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value-1114.0-1126.0-1139.0-1009.0-1259.0-771.0-718.0-504.0-807.0-793.0-803.0-1089.0-1102.0-1114.0-1147.0-829.0-831.0-1079.0608-232.0-128.0913593
Percentage of StockholdersEquity-22.7-21.6-19.1-14.4-14.8-8.2-6.2-4.5-7.8-8.1-8.0-11.5-12.8-13.4-13.0-9.6-9.3-45.020.4-48.2-7.15.3-1.2-4.0
Percentage of Assets-1.6-1.8-1.9-1.6-2.3-1.5-1.4-1.0-1.5-1.6-1.8-2.4-2.5-2.5-2.7-2.1-2.0-2.91.7-0.6-0.30.20.20.0
Percentage of Assets ual:UnitedAirLinesInc us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ual:UnitedAirLinesInc, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value18511785683010.00.00.00.08459882284112331787357361387347759034443432342134012831
Percentage of StockholdersEquity3.82.21.41.00.40.10.00.00.00.96.08.79.714.820.341.368.5306.6254.4716.0190.0198.1-121.0-122.0
Percentage of Assets0.30.20.10.10.10.00.00.00.00.21.31.81.92.84.28.915.019.720.69.29.08.618.20.0
Percentage of Assets ual:UnitedAirLinesInc us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ual:UnitedAirLinesInc, us-gaap:ReceivablesFromStockholder


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value26532602204310781038-161.0-143.0-142.0-141.0-140.0-110.0-109.0-108.0-108.0-90.0-75.0-17.0-5.0-232.0
Percentage of StockholdersEquity54.150.034.315.412.2-1.7-1.2-1.3-1.4-1.4-1.1-1.2-1.3-1.3-1.0-0.9-0.2-0.2-7.8
Percentage of Assets3.74.23.41.81.9-0.3-0.3-0.3-0.3-0.3-0.2-0.2-0.2-0.2-0.2-0.2-0.0-0.0-0.6
Percentage of Assets ual:UnitedAirLinesInc us-gaap:ReceivablesFromStockholder0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ual:UnitedAirLinesInc, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value31483582493968358676103021235311909112301061210272985690228339821859373673-3628.0-4743.0-6396.0-5208.0-5489.0-5888.0-5260.0
Percentage of StockholdersEquity64.268.882.997.6101.9109.4107.1105.4108.8108.3102.8104.1104.4100.093.368.641.0-151.4-158.9-1329.7-288.4-317.8209.5226.6
Percentage of Assets4.45.88.311.215.819.423.522.821.521.022.922.020.218.919.414.89.0-9.7-12.9-17.0-13.7-13.9-31.50.0
Percentage of Assets ual:UnitedAirLinesInc us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value-1114.0-1126.0-1139.0-1009.0-1259.0-771.0-718.0-504.0-807.0-793.0-803.0-1089.0-1102.0-1114.0-1147.0-824.0-844.0-836.0-829.0-798.0-734.0-777.0-831.0-934.0-812.0-977.0-1079.0608-1046.0-417.03873593141
Percentage of StockholdersEquity-22.7-21.6-19.1-14.4-14.8-8.2-6.2-4.5-7.8-8.1-8.0-11.5-12.8-13.4-13.0-9.2-9.5-9.9-9.6-9.5-9.4-9.9-9.3-10.9-19.7-32.5-45.020.4-217.5-23.122.4-1.2-4.05.4
Percentage of Assets-1.6-1.8-1.9-1.6-2.3-1.5-1.4-1.0-1.5-1.6-1.8-2.4-2.5-2.5-2.7-1.9-2.0-2.0-2.1-2.0-1.8-1.9-2.0-2.2-2.1-2.5-2.91.7-2.8-1.11.00.20.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value9042892383667383730760966129611160966080612061056091607760986569794677217425714571147071313629192392
Percentage of StockholdersEquity184.4171.4140.4105.485.864.753.254.159.162.061.264.570.572.969.275.988.6322.2248.81485.4393.9409.4-111.6-125.891.6
Percentage of Assets12.714.514.012.113.311.511.611.711.712.013.713.613.613.814.416.419.420.720.219.018.717.916.80.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value4.04.04.03.03.03.03.03.03.03.03.03.03.03.03.03.04.04.04.03.03.03.02.01.01.0
Percentage of StockholdersEquity0.10.10.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.20.10.60.20.2-0.1-0.00.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value8041239262645246365799197169075805069996668625254194736462134273457-3883.0-5015.0-5586.0-4863.0-5703.0-5956.0-5308.091
Percentage of StockholdersEquity16.423.844.164.674.784.884.380.378.071.466.766.062.756.852.539.638.6-162.1-168.1-1161.3-269.3-330.2211.9228.73.5
Percentage of Assets1.12.04.47.411.615.118.517.415.413.814.913.912.110.810.98.58.5-10.4-13.6-14.8-12.8-14.4-31.90.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value-3832.0-3834.0-3897.0-3898.0-3899.0-3901.0-3599.0-3384.0-3022.0-2487.0-1993.0-1753.0-1720.0-1314.0-769.0-511.0-1610.0-367.0-38.0-35.0-31.0-31.0-28.0-26.0-15.0
Percentage of StockholdersEquity-78.1-73.6-65.4-55.7-45.8-41.4-31.2-29.9-29.3-25.4-19.9-18.5-19.9-15.8-8.7-5.9-18.0-15.3-1.3-7.3-1.7-1.81.01.1-0.6
Percentage of Assets-5.4-6.2-6.5-6.4-7.1-7.4-6.8-6.5-5.8-4.9-4.4-3.9-3.8-3.0-1.8-1.3-3.9-1.0-0.1-0.1-0.1-0.1-0.10.00.0
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Assets Current

us-gaap:AssetsCurrent

us-gaap:AssetsCurrent


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value24673160191480016476100417905819485338910760871948671888182877113787782487724730979707844722478281009787939509813892259619878887029389962191481004910774117081126110997119861239113148120455105
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets34.726.024.926.918.314.915.616.317.115.016.119.319.918.816.818.519.518.618.219.819.417.919.224.122.324.321.824.325.023.623.625.225.724.826.728.430.329.528.930.731.232.430.427.3

us-gaap:AssetsCurrent dei:LegalEntity

ual:UnitedAirLinesInc


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value246731601914800164761004178998188852789047602718886658875828271077870824377197303801378877267786910137883595518181926896548824869596089837937284929152980082705899654667106901
Percentage of AssetsCurrent100.0100.0100.0100.0100.099.999.999.999.999.999.999.999.999.999.999.999.999.999.9100.5100.5100.6100.5100.4100.5100.4100.5100.5100.4100.499.9102.3102.2102.484.584.983.773.453.654.654.257.3
Percentage of Assets34.726.024.926.918.314.915.616.317.115.016.019.319.918.816.818.519.518.618.219.919.518.019.324.222.424.421.924.425.123.723.625.826.325.422.624.125.321.615.516.816.917.4
Percentage of Assets ual:UnitedAirLinesInc34.726.024.926.918.314.915.616.317.115.016.019.319.918.816.818.519.518.618.219.919.518.019.324.222.424.421.524.024.823.323.325.425.825.040.842.443.438.032.334.735.035.2

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-312009-12-312008-12-312007-12-31
Value20838126661126913150650534422762295932211848169426212884240414821870237121642179263024831795300634272796335220023117342430093220393541433538477051296086560662466984751981658069493849063516304220391259
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets29.320.518.921.511.86.55.25.76.23.63.85.86.55.53.54.45.65.25.46.56.14.47.48.27.18.65.48.28.98.18.710.611.19.612.713.515.714.716.417.918.920.120.40.00.00.016.30.00.0

us-gaap:CashAndCashEquivalentsAtCarryingValue dei:LegalEntity

ual:UnitedAirLinesInc


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302009-12-312008-12-31
Value208381266611269131506505343627562953321518421688261528782398147618642365215821732624247717893000342127903346199631113418300332143928413735322766300540763338345840704107480646654932490030362033
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.099.899.899.899.899.799.699.899.899.899.699.799.799.799.799.899.899.799.899.899.899.899.799.899.899.899.899.899.999.858.058.667.059.555.458.354.658.957.899.999.999.899.7
Percentage of Assets29.320.518.921.511.86.55.25.76.23.63.85.86.45.43.54.45.65.25.46.56.14.47.38.27.18.65.38.28.98.18.710.511.09.67.47.910.58.79.110.410.311.911.80.00.016.20.0
Percentage of Assets ual:UnitedAirLinesInc29.320.618.921.511.86.55.25.76.23.63.85.86.45.43.54.45.65.25.46.56.14.47.38.27.18.65.28.18.87.98.610.410.99.413.313.918.115.319.021.621.40.023.80.00.00.00.0

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312015-12-31
Value21308131381174213398661235482868306333261951179927262991251015911979250123033212
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets30.021.319.721.912.06.75.55.96.43.94.06.16.75.73.84.65.95.77.9

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents dei:LegalEntity

ual:UnitedAirLinesInc


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312015-12-31
Value21308131381174213398661235422862305733201945179327202985250415851973249522973206
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.099.899.899.899.899.799.799.899.899.899.699.799.899.799.8
Percentage of Assets30.021.319.721.912.06.75.45.96.43.84.06.16.75.73.74.65.95.77.8
Percentage of Assets ual:UnitedAirLinesInc30.021.319.721.912.06.75.45.96.43.84.06.16.75.73.74.65.95.77.8

Short Term Investments

us-gaap:ShortTermInvestments

us-gaap:ShortTermInvestments


Short
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value230309414552958177921822167222322192256231421872071231624582278221522492226220221772190217221892256238223972372201519011801182118521773155116181667151613731060722611
Percentage of ShortTermInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.30.50.70.91.73.44.14.24.34.45.05.24.94.75.55.85.45.35.65.55.45.45.45.25.65.86.46.36.25.45.24.84.95.04.74.14.24.44.03.52.71.81.5

us-gaap:ShortTermInvestments dei:LegalEntity

ual:UnitedAirLinesInc


Short
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value23030941455295817792182216722232219225623142187207123162458227822152249222622022177219021722189225623822397237220151901180118211852326346342338275186155
Percentage of ShortTermInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.018.422.321.120.318.113.514.6
Percentage of Assets0.30.50.70.91.73.44.14.24.34.45.05.24.94.75.55.85.45.35.65.55.45.45.45.25.65.86.46.36.25.45.24.84.95.00.90.90.90.90.70.50.4
Percentage of Assets ual:UnitedAirLinesInc0.30.50.70.91.73.44.14.24.34.45.05.24.94.75.55.85.45.45.65.55.45.45.45.25.65.86.36.26.15.35.14.84.84.91.61.61.51.61.51.00.8

Receivables Net Current

us-gaap:ReceivablesNetCurrent

us-gaap:ReceivablesNetCurrent


Receivables
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value17931389129511718577921364161717621789134617521840176013401603149914291176148114501581112815131471147111461559166516091503169317321679133818621818190813581713186323571613743
Percentage of ReceivablesNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.52.32.21.91.61.52.63.13.43.53.03.94.14.03.23.83.53.42.93.73.63.92.83.63.73.83.14.14.34.34.14.54.64.63.64.94.75.03.64.44.75.84.14.0

us-gaap:ReceivablesNetCurrent dei:LegalEntity

ual:UnitedAirLinesInc


Receivables
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value17931389129511718577921364161717621789134617521840176013401603149914291176148114501581112815131471147111461559166516091503169317321679119416861568164176386511031004
Percentage of ReceivablesNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.089.290.586.286.056.250.559.262.2
Percentage of Assets2.52.32.21.91.61.52.63.13.43.53.03.94.14.03.23.83.53.42.93.73.63.92.83.63.73.83.14.14.34.34.14.54.64.63.24.44.14.32.02.22.82.5
Percentage of Assets ual:UnitedAirLinesInc2.52.32.21.91.61.52.63.13.43.53.03.94.14.03.23.83.53.52.93.73.63.92.83.63.73.83.04.04.34.34.04.54.54.55.77.86.97.54.24.65.85.1

Prepaid Expense And Other Assets Current

us-gaap:PrepaidExpenseAndOtherAssetsCurrent

us-gaap:PrepaidExpenseAndOtherAssetsCurrent


Prepaid
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value646483635566766822814725708780913973102811281051100912181016832791911912740819881826730838839845704700790845865837797783607595773658
Percentage of PrepaidExpenseAndOtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.90.81.10.91.41.51.51.41.41.52.02.22.32.62.52.42.92.52.12.02.32.31.82.02.22.12.02.22.22.31.91.92.12.32.32.22.12.01.61.51.91.7

us-gaap:PrepaidExpenseAndOtherAssetsCurrent dei:LegalEntity

ual:UnitedAirLinesInc


Prepaid
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value646483635566766822814725708780913973102811291051100812191017832840960961787867929874779887887893705685777841700633619524447413513366
Percentage of PrepaidExpenseAndOtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.1100.099.9100.1100.1100.0106.2105.4105.4106.4105.9105.4105.8106.7105.8105.7105.7100.197.998.499.580.975.677.766.973.669.466.455.6
Percentage of Assets0.90.81.10.91.41.51.51.41.41.52.02.22.32.62.52.42.92.52.12.12.42.41.92.12.42.22.12.32.32.41.91.82.12.31.91.71.61.41.21.11.30.9
Percentage of Assets ual:UnitedAirLinesInc0.90.81.10.91.41.51.51.41.41.52.02.22.32.62.52.42.92.52.12.12.42.41.92.12.42.22.02.32.32.41.91.82.02.23.42.92.72.42.42.22.71.9

Goodwill

us-gaap:Goodwill

us-gaap:Goodwill


Goodwill
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-31
Value4527452745274527452345234523452345234523452345234523452345234523452345234523452345234523452345234523452345234523452345234523452345234523452345234523452345234523452345234523
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.47.37.67.48.28.58.68.78.78.910.110.110.110.310.710.610.710.911.311.211.211.211.110.811.511.612.111.911.812.212.312.112.112.312.011.911.711.811.911.611.411.211.4

us-gaap:Goodwill dei:LegalEntity

ual:UnitedAirLinesInc


Goodwilldei:
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-31
Value45274527452745274523452345234523452345234523452345234523452345234523452345234523452345234523452345234523452345234523452345234523452345234523
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.47.37.67.48.28.58.68.78.78.910.110.110.110.310.710.610.710.911.311.211.211.211.110.811.511.612.111.911.812.212.312.112.112.312.0
Percentage of Assets ual:UnitedAirLinesInc6.47.37.67.48.28.58.68.78.78.910.110.110.110.310.710.610.710.911.311.211.211.211.110.811.511.611.911.711.612.012.111.911.912.121.7

Indefinite Lived Intangible Assets Excluding Goodwill

us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill

us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill


Indefinite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value2577269327833095309535093542356535843614
Percentage of IndefiniteLivedIntangibleAssetsExcludingGoodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.35.16.27.37.78.69.59.79.59.5

us-gaap:IndefiniteLivedIntangibleAssetsExcludingGoodwill us-gaap:IndefiniteLivedIntangibleAssetsByMajorClass

ual:AirportSlotsAndGatesIndefiniteLived


Indefinite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value560546546536536942956
Percentage of IndefiniteLivedIntangibleAssetsExcludingGoodwill21.720.319.617.317.326.827.0
Percentage of Assets0.91.01.21.31.32.32.6
Percentage of Assets ual:AirportSlotsAndGatesIndefiniteLived0.00.00.00.00.00.00.0

ual:RouteAuthorities


Indefinite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value1020115012401562156215701589160516061606
Percentage of IndefiniteLivedIntangibleAssetsExcludingGoodwill39.642.744.650.550.544.744.945.044.844.4
Percentage of Assets1.72.22.83.73.93.84.34.44.34.2
Percentage of Assets ual:RouteAuthorities0.00.00.00.00.00.00.00.00.00.0

us-gaap:UseRights


Indefinite
Period End2020-09-30
Value1100
Percentage of IndefiniteLivedIntangibleAssetsExcludingGoodwill0.0
Percentage of Assets1.8
Percentage of Assets us-gaap:UseRights0.0

Intangible Assets Net Excluding Goodwill

us-gaap:IntangibleAssetsNetExcludingGoodwill

us-gaap:IntangibleAssetsNetExcludingGoodwill


Intangible
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value28272840283828522852294530093114312931443159338233993521353935583592361236323654367741124136419342204257428443304372440244364487452345614597465046814712475047724815486649172455
Percentage of IntangibleAssetsNetExcludingGoodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.04.64.84.75.25.65.76.06.06.27.17.57.68.08.48.48.58.79.09.19.110.210.110.010.710.911.511.411.411.812.112.012.112.412.212.312.112.312.512.212.112.012.413.1

us-gaap:IntangibleAssetsNetExcludingGoodwill dei:LegalEntity

ual:UnitedAirLinesInc


Intangible
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value282728402838285228522945300931143129314431593382339935213539355835923612363236543677411241364193422042574284433043724402443644874523456122282241225522692283229823132343
Percentage of IntangibleAssetsNetExcludingGoodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.048.548.248.248.248.148.248.047.7
Percentage of Assets4.04.64.84.75.25.65.76.06.06.27.17.57.68.08.48.48.58.79.09.19.110.210.110.010.710.911.511.411.411.812.112.012.112.45.95.95.85.96.05.95.85.9
Percentage of Assets ual:UnitedAirLinesInc4.04.64.84.75.25.65.76.06.06.27.17.57.68.08.48.48.58.79.19.19.110.210.110.010.710.911.211.211.211.611.911.911.912.210.710.410.010.412.512.212.111.9

Deferred Tax Assets Liabilities Net

us-gaap:DeferredTaxAssetsLiabilitiesNet

us-gaap:DeferredTaxAssetsLiabilitiesNet


Deferred
Period End2020-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value1316552037-1000.0-987.0-1000.0-988.0-994.0
Percentage of DeferredTaxAssetsLiabilitiesNet100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.21.65.0-2.7-2.7-2.7-2.6-2.5

us-gaap:DeferredTaxAssetsLiabilitiesNet dei:LegalEntity

ual:UnitedAirLinesInc


Deferred
Period End2020-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value1036121995-1000.0-987.0-376.0-359.0
Percentage of DeferredTaxAssetsLiabilitiesNet78.693.497.9100.0100.037.636.3
Percentage of Assets0.21.54.9-2.7-2.7-1.0-0.9
Percentage of Assets ual:UnitedAirLinesInc0.21.54.9-2.6-2.6-1.8-2.0

Operating Lease Right Of Use Asset

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:OperatingLeaseRightOfUseAsset


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value44214516453745444738485347584937490850655262
Percentage of OperatingLeaseRightOfUseAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.27.37.67.48.69.19.09.59.410.011.7

us-gaap:OperatingLeaseRightOfUseAsset dei:LegalEntity

ual:UnitedAirLinesInc


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value44214516453745444738485347584937490850655262
Percentage of OperatingLeaseRightOfUseAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.27.37.67.48.69.19.09.59.410.011.7
Percentage of Assets ual:UnitedAirLinesInc6.27.37.67.48.69.19.09.59.410.011.7

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent

us-gaap:OtherAssetsNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value9624921287458519838784869489939794149380926988588864899290059059904294809513971210244111431145310596987397209748984399711001310063101051026310257102871032110409730770795816731715983
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets13.514.914.713.915.316.018.018.018.118.520.719.819.820.421.321.321.422.923.724.125.327.628.025.325.124.926.125.925.926.927.327.127.427.827.327.226.91.92.02.02.11.81.85.3

us-gaap:OtherAssetsNoncurrent dei:LegalEntity

ual:UnitedAirLinesInc


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value9596918487178519838784869489939794149380926988598864899290059059899894359470967010202111001141210557987397201046010341104201059810544104791065610669336435593903602600570602622
Percentage of OtherAssetsNoncurrent99.799.799.7100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.599.599.599.699.699.699.699.6100.0100.0107.3105.1104.5105.8104.8103.7103.8104.032.734.537.582.577.971.773.887.0
Percentage of Assets13.514.914.613.915.316.018.018.018.118.520.719.819.820.421.321.321.322.823.624.025.227.527.925.225.124.928.027.227.128.528.628.128.429.08.99.410.11.61.61.51.51.6
Percentage of Assets ual:UnitedAirLinesInc13.514.914.613.915.316.018.018.018.118.520.719.819.820.421.321.321.322.823.624.025.227.527.925.225.124.827.426.826.828.028.327.728.028.516.216.517.32.83.33.03.13.2

Equity Securities Fv Ni

us-gaap:EquitySecuritiesFvNi us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:EquitySecuritiesFvNi

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-03-312019-12-312019-09-302019-06-302018-12-31
Value26918220511892385322301249
Percentage of EquitySecuritiesFvNi100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.40.30.30.20.20.70.60.60.6
Percentage of Assets us-gaap:FairValueInputsLevel1 us-gaap:FairValueMeasurementsRecurring0.00.00.00.00.00.00.00.00.0

us-gaap:EquitySecuritiesFvNi us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-312019-09-302019-06-302018-12-31
Value269182205118101385322301249
Percentage of EquitySecuritiesFvNi100.0100.0100.0100.00.0100.0100.0100.0100.0
Percentage of Assets0.40.30.30.20.20.70.60.60.6
Percentage of Assets us-gaap:FairValueMeasurementsRecurring0.00.00.00.00.00.00.00.00.0

us-gaap:EquitySecuritiesFvNi us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

ual:Azul


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value23818220511810192385
Percentage of EquitySecuritiesFvNi88.5100.0100.0100.00.0100.0100.0
Percentage of Assets0.30.30.30.20.20.20.7
Percentage of Assets ual:Azul0.00.00.00.00.00.00.0

ual:ClearSecureInc


Equity
Period End2021-06-30
Value31
Percentage of EquitySecuritiesFvNi11.5
Percentage of Assets0.0
Percentage of Assets ual:ClearSecureInc0.0

Accounts Payable Current

us-gaap:AccountsPayableCurrent

us-gaap:AccountsPayableCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value2218183815951831172524362703284830332707236325812703239921962231222521352139213822402065186920822322207418822085244123322087212622982293231221882165222019981808199918971805803
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.13.02.73.03.14.65.15.55.85.35.35.86.05.55.25.25.35.25.35.35.55.14.65.05.95.35.05.56.36.35.75.76.16.26.15.85.65.85.34.65.04.74.64.3

us-gaap:AccountsPayableCurrent dei:LegalEntity

ual:UnitedAirLinesInc


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value22181838159518311725243627032848303327072363258127032399219622312230214121442143224520691874208623272079188620892446233620922131230222961518142614061385110910221161907
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.2100.3100.2100.2100.2100.2100.3100.2100.2100.2100.2100.2100.2100.2100.2100.2100.2100.165.765.264.962.455.556.558.150.2
Percentage of Assets3.13.02.73.03.14.65.15.55.85.35.35.86.05.55.25.25.35.25.35.35.55.14.65.05.95.35.05.56.46.35.75.76.16.24.03.83.63.62.92.62.92.3
Percentage of Assets ual:UnitedAirLinesInc3.13.02.73.03.14.65.15.55.85.35.35.86.05.55.25.25.35.25.35.35.55.14.65.05.95.34.95.46.36.25.65.66.06.17.36.66.26.46.15.46.14.6

Contract With Customer Liability Current

us-gaap:ContractWithCustomerLiabilityCurrent us-gaap:ProductOrService

us-gaap:ContractWithCustomerLiabilityCurrent

ual:AdvanceTicketSales


Contract
Period End2020-12-312020-09-302019-09-302019-06-302018-12-31
Value31003000551561264381
Percentage of ContractWithCustomerLiabilityCurrent100.0100.0100.0100.0100.0
Percentage of Assets5.24.910.611.79.8
Percentage of Assets ual:AdvanceTicketSales0.00.00.00.00.0

Liabilities Current

us-gaap:LiabilitiesCurrent

us-gaap:LiabilitiesCurrent


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value180641416712725157911639516087149381569116078153351321213684140921418312676130871359612662122861325313982133801241413488138101396912508128641333413091121071260412927128921281813057133121248611394118981276213874126456473
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets25.423.021.425.829.930.328.430.130.830.329.530.531.532.229.930.732.130.630.632.934.533.130.432.235.135.733.533.834.735.232.933.834.535.034.134.434.432.730.030.532.234.231.934.6

us-gaap:LiabilitiesCurrent dei:LegalEntity

ual:UnitedAirLinesInc


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1806814170127291579516399160911494315696160821534013217136891409614189126811309113602126671229013257139871338412417134921381413974125131286913430131881222512712130441304210626108361109698206927701175067892
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.7100.7101.0100.9100.9101.282.983.083.478.660.858.958.862.4
Percentage of Assets25.423.021.425.829.930.328.430.130.830.329.530.531.532.230.030.832.230.630.632.934.633.230.432.235.135.733.533.934.935.533.234.134.835.428.228.628.725.718.218.018.919.9
Percentage of Assets ual:UnitedAirLinesInc25.423.021.425.829.930.328.430.130.830.329.530.531.532.230.030.832.230.630.732.934.633.230.432.235.135.732.833.434.534.932.833.634.334.851.150.249.245.138.037.239.240.2

Long Term Debt Current

us-gaap:LongTermDebtCurrent

us-gaap:LongTermDebtCurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value188117831911458444544055140712431255120112309108871655156515161436716849969127212951224131210471700131313401168117813689579091079181217041349101311861201138923192411545
Percentage of LongTermDebtCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.62.93.27.58.17.62.72.42.42.42.72.02.03.83.73.63.41.72.12.43.13.23.03.12.74.33.53.53.03.23.72.62.42.94.84.53.52.73.13.13.55.76.12.9

us-gaap:LongTermDebtCurrent dei:LegalEntity

ual:UnitedAirLinesInc


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value18811783191145844454405514071243125512011230910887165515651516143671684996912721295122413121047170013131340116811781368957909107910909786436156154766351546
Percentage of LongTermDebtCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.060.257.447.760.751.939.645.764.1
Percentage of Assets2.62.93.27.58.17.62.72.42.42.42.72.02.03.83.73.63.41.72.12.43.13.23.03.12.74.33.53.53.03.23.72.62.42.92.92.61.71.61.61.21.63.9
Percentage of Assets ual:UnitedAirLinesInc2.62.93.27.58.17.62.72.42.42.42.72.02.03.83.73.63.41.72.12.43.13.23.03.12.74.33.43.53.03.13.72.52.42.95.24.52.82.83.42.53.37.9

Operating Lease Liability Current

us-gaap:OperatingLeaseLiabilityCurrent

us-gaap:OperatingLeaseLiabilityCurrent


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value583623612623598688686778637639719
Percentage of OperatingLeaseLiabilityCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.81.01.01.01.11.31.31.51.21.31.6

us-gaap:OperatingLeaseLiabilityCurrent dei:LegalEntity

ual:UnitedAirLinesInc


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value583623612623598688686778637639719
Percentage of OperatingLeaseLiabilityCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.81.01.01.01.11.31.31.51.21.31.6
Percentage of Assets ual:UnitedAirLinesInc0.81.01.01.01.11.31.31.51.21.31.6

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent

us-gaap:OtherLiabilitiesCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302018-12-31
Value819724724944558538566574604553
Percentage of OtherLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.21.21.21.51.01.01.11.11.21.2

us-gaap:OtherLiabilitiesCurrent dei:LegalEntity

ual:UnitedAirLinesInc


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302018-12-31
Value823727728948562542571579608558
Percentage of OtherLiabilitiesCurrent100.5100.4100.6100.4100.7100.7100.9100.9100.7100.9
Percentage of Assets1.21.21.21.51.01.01.11.11.21.2
Percentage of Assets ual:UnitedAirLinesInc1.21.21.21.51.01.01.11.11.21.2

Long Term Debt

us-gaap:LongTermDebt dei:LegalEntity

us-gaap:LongTermDebt

ual:UalAndUnited


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value3478428165273012740118958174561473314324143791412413636132881351313985134311301612266120311089111042
Percentage of LongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets49.045.745.844.834.532.928.027.427.627.930.429.630.231.831.730.629.029.027.127.0
Percentage of Assets ual:UalAndUnited0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:LongTermDebt us-gaap:DebtInstrument

ual:FloatingRateDebt


Long
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value13400104001230076006000340034003400
Percentage of LongTermDebt38.536.944.940.134.423.723.624.1
Percentage of Assets18.916.920.113.811.36.56.56.7
Percentage of Assets ual:FloatingRateDebt0.00.00.00.00.00.00.00.0

ual:PassThroughCertificates


Long
Period End2020-12-312019-12-31
Value121009600
Percentage of LongTermDebt44.365.2
Percentage of Assets20.318.2
Percentage of Assets ual:PassThroughCertificates0.00.0

us-gaap:LongTermDebt us-gaap:FairValueByMeasurementBasis

us-gaap:CarryingReportedAmountFairValueDisclosure


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302012-12-31
Value34184276322674726881187721725314552141431419313935134451312813347138211326812850121041189410767105811054710767108971122210985116141143411328115221127611539111611112312252
Percentage of LongTermDebt98.398.198.098.199.098.898.898.798.798.798.698.898.898.898.898.798.798.998.90.00.00.098.70.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets48.144.844.943.934.232.527.727.127.227.530.029.329.931.431.330.228.628.726.826.226.126.726.726.827.929.730.629.830.030.331.330.029.732.6
Percentage of Assets us-gaap:CarryingReportedAmountFairValueDisclosure0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Long Term Debt Noncurrent

us-gaap:LongTermDebtNoncurrent

us-gaap:LongTermDebtNoncurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value32303258492483622297143181319813145129001293812734122151221812460121661170311334106681117899189612927594729673991099389914101219988103541009810171102041021410182104409592101281040810496108731110111115114346378
Percentage of LongTermDebtNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets45.541.941.736.426.124.925.024.724.825.127.327.227.927.627.626.625.227.024.723.822.923.523.723.725.225.427.126.326.927.227.627.427.327.627.725.326.227.227.627.828.027.428.934.1

us-gaap:LongTermDebtNoncurrent dei:LegalEntity

ual:UnitedAirLinesInc


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value32303258492483622297143181319813145129001293812734122151221812460121661170311334106681117899189612927594729673991099389914101209892102559996100201005110007978342854191488849875130535054685480
Percentage of LongTermDebtNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.099.099.098.598.598.096.141.043.748.347.948.949.249.347.9
Percentage of Assets45.541.941.736.426.124.925.024.724.825.127.327.227.927.627.626.625.227.024.723.822.923.523.723.725.225.427.126.026.726.927.227.026.726.611.411.112.613.113.513.713.813.8
Percentage of Assets ual:UnitedAirLinesInc45.541.941.736.426.124.925.024.724.825.127.327.327.927.627.726.625.227.024.723.822.923.523.723.725.225.326.625.726.326.426.926.626.326.120.619.421.722.928.128.428.527.9

Deferred Income Tax Liabilities Net

us-gaap:DeferredIncomeTaxLiabilitiesNet

us-gaap:DeferredIncomeTaxLiabilitiesNet


Deferred
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value3898041322173615941192898814639419204
Percentage of DeferredIncomeTaxLiabilitiesNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.61.52.53.33.12.31.81.81.40.90.5

us-gaap:DeferredIncomeTaxLiabilitiesNet dei:LegalEntity

ual:UnitedAirLinesInc


Deferred
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value4168321350176316221220925842666446231
Percentage of DeferredIncomeTaxLiabilitiesNet106.9103.5102.1101.6101.8102.3103.0103.4104.2106.4113.2
Percentage of Assets0.71.52.53.43.12.31.81.91.51.00.5
Percentage of Assets ual:UnitedAirLinesInc0.71.52.53.43.12.31.81.91.51.00.5

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent us-gaap:RetirementPlanType

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Pension
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value994789129516021581
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.0100.0100.0
Percentage of Assets1.71.52.93.83.9
Percentage of Assets us-gaap:OtherPostretirementBenefitPlansDefinedBenefit0.00.00.00.00.0

us-gaap:PensionPlansDefinedBenefit


Pension
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value24601446157619211892
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent247.5183.3121.7119.9119.7
Percentage of Assets4.12.73.54.54.7
Percentage of Assets us-gaap:PensionPlansDefinedBenefit0.00.00.00.00.0

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:OtherLiabilitiesNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value135012981156117414301179102498198073878236835084618314814582068245832084558271869589569081915410934116401175713711371128112831298139213281366135613641351139513221314261527041001
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.92.11.91.92.62.21.91.91.914.618.418.618.918.919.219.319.520.121.120.521.522.222.221.927.829.831.53.63.63.43.53.53.73.63.63.63.53.53.73.43.36.46.85.4

us-gaap:OtherLiabilitiesNoncurrent dei:LegalEntity

ual:UnitedAirLinesInc


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value1350129811561174143011791025980980741582638377848883418172825082458320845582728695895690819154109341164012269166716341634155214831591153710351044959980983952956972
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.199.9100.0100.4100.3100.3100.3100.3100.3100.5100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0104.4121.6119.2127.6121.0114.3114.3115.775.877.070.372.570.572.072.835.9
Percentage of Assets1.92.11.91.92.62.21.91.91.914.618.418.719.018.919.319.419.520.121.120.521.522.222.221.927.829.832.84.44.34.44.24.04.24.22.82.82.52.62.62.42.42.5
Percentage of Assets ual:UnitedAirLinesInc1.92.11.91.92.62.21.91.91.914.618.418.719.019.019.319.419.520.121.120.521.522.222.221.927.729.732.24.34.24.34.23.94.24.15.04.84.34.55.45.15.05.0

Operating Lease Liability Noncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value49204985498649435113506049464941503451455276
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.98.18.48.19.39.59.49.59.710.211.8

us-gaap:OperatingLeaseLiabilityNoncurrent dei:LegalEntity

ual:UnitedAirLinesInc


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value49204985498649435113506049464941503451455276
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.98.18.48.19.39.59.49.59.710.211.8
Percentage of Assets ual:UnitedAirLinesInc6.98.18.48.19.39.59.49.59.710.211.8

Lessee Operating Lease Liability Payments Due Year Two

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo


Lessee
Period End2020-12-31
Value693
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo100.0
Percentage of Assets1.2

Lessee Operating Lease Liability Payments Due Year Three

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree


Lessee
Period End2020-12-31
Value723
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree100.0
Percentage of Assets1.2

Lessee Operating Lease Liability Payments Due Year Four

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour


Lessee
Period End2020-12-31
Value704
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour100.0
Percentage of Assets1.2

Lessee Operating Lease Liability Payments Due Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive


Lessee
Period End2020-12-31
Value585
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive100.0
Percentage of Assets1.0

Lessee Operating Lease Liability Payments Due After Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive


Lessee
Period End2020-12-31
Value3979
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive100.0
Percentage of Assets6.7

Operating Lease Liability

us-gaap:OperatingLeaseLiability

us-gaap:OperatingLeaseLiability


Operating
Period End2020-12-31
Value5598
Percentage of OperatingLeaseLiability100.0
Percentage of Assets9.4

Lessee Operating Lease Liability Payments Due

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue


Lessee
Period End2020-12-31
Value7531
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue100.0
Percentage of Assets12.6

Lessee Operating Lease Liability Undiscounted Excess Amount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount


Lessee
Period End2020-12-31
Value1933
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount100.0
Percentage of Assets3.2

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-312007-12-31
Value4904520659607003851794181153111301103209802999594698639833688068970885484498659843977847840896685554122300823963864334725792984172812179448118271635151018062312194219121727-2811.0-2321.02610
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.98.410.011.415.517.821.921.619.819.422.321.119.318.920.821.120.920.421.620.919.219.421.920.410.57.76.410.28.76.98.14.63.20.31.34.84.24.04.85.94.94.74.4-15.00.00.0

us-gaap:StockholdersEquity dei:LegalEntity

ual:UnitedAirLinesInc


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-312008-12-31
Value487251755928697284859380114921126310282976399579432860282988768891587998394860684357780783689638552416030462635419935772857322322461787840-3184.0-2470.0-2447.0-2248.0-1904.0-1719.0-1950.0-1977.0-2452.0-2336.0
Percentage of StockholdersEquity99.399.499.599.699.699.699.799.799.699.699.699.699.699.599.699.499.499.399.4100.099.999.9100.0100.0100.9101.3110.0108.7106.9110.8108.0130.0146.8893.6-662.0-135.2-149.7-148.9-105.4-74.4-100.4-114.587.2100.6
Percentage of Assets6.98.410.011.415.517.721.821.619.719.322.221.019.218.920.720.920.820.321.420.919.219.421.920.410.67.87.111.09.37.78.86.04.82.3-8.5-6.5-6.3-5.9-5.0-4.4-4.9-5.0-13.10.0
Percentage of Assets ual:UnitedAirLinesInc6.98.410.011.415.517.721.821.619.719.322.221.019.318.920.720.920.820.321.520.919.219.421.920.410.67.86.910.99.27.68.65.94.72.2-15.3-11.4-10.8-10.3-10.4-9.1-10.2-10.10.00.0

us-gaap:StockholdersEquity dei:LegalEntity, us-gaap:StatementEquityComponents

ual:UnitedAirLinesInc, us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value-1114.0-1126.0-1139.0-1009.0-1259.0-771.0-718.0-504.0-807.0-793.0-803.0-1089.0-1102.0-1114.0-1147.0-829.0-831.0-1079.0608-232.0-128.0913593
Percentage of StockholdersEquity-22.7-21.6-19.1-14.4-14.8-8.2-6.2-4.5-7.8-8.1-8.0-11.5-12.8-13.4-13.0-9.6-9.3-45.020.4-48.2-7.15.3-1.2-4.0
Percentage of Assets-1.6-1.8-1.9-1.6-2.3-1.5-1.4-1.0-1.5-1.6-1.8-2.4-2.5-2.5-2.7-2.1-2.0-2.91.7-0.6-0.30.20.20.0
Percentage of Assets ual:UnitedAirLinesInc us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ual:UnitedAirLinesInc, us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value18511785683010.00.00.00.08459882284112331787357361387347759034443432342134012831
Percentage of StockholdersEquity3.82.21.41.00.40.10.00.00.00.96.08.79.714.820.341.368.5306.6254.4716.0190.0198.1-121.0-122.0
Percentage of Assets0.30.20.10.10.10.00.00.00.00.21.31.81.92.84.28.915.019.720.69.29.08.618.20.0
Percentage of Assets ual:UnitedAirLinesInc us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ual:UnitedAirLinesInc, us-gaap:ReceivablesFromStockholder


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value26532602204310781038-161.0-143.0-142.0-141.0-140.0-110.0-109.0-108.0-108.0-90.0-75.0-17.0-5.0-232.0
Percentage of StockholdersEquity54.150.034.315.412.2-1.7-1.2-1.3-1.4-1.4-1.1-1.2-1.3-1.3-1.0-0.9-0.2-0.2-7.8
Percentage of Assets3.74.23.41.81.9-0.3-0.3-0.3-0.3-0.3-0.2-0.2-0.2-0.2-0.2-0.2-0.0-0.0-0.6
Percentage of Assets ual:UnitedAirLinesInc us-gaap:ReceivablesFromStockholder0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

ual:UnitedAirLinesInc, us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value31483582493968358676103021235311909112301061210272985690228339821859373673-3628.0-4743.0-6396.0-5208.0-5489.0-5888.0-5260.0
Percentage of StockholdersEquity64.268.882.997.6101.9109.4107.1105.4108.8108.3102.8104.1104.4100.093.368.641.0-151.4-158.9-1329.7-288.4-317.8209.5226.6
Percentage of Assets4.45.88.311.215.819.423.522.821.521.022.922.020.218.919.414.89.0-9.7-12.9-17.0-13.7-13.9-31.50.0
Percentage of Assets ual:UnitedAirLinesInc us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value-1114.0-1126.0-1139.0-1009.0-1259.0-771.0-718.0-504.0-807.0-793.0-803.0-1089.0-1102.0-1114.0-1147.0-824.0-844.0-836.0-829.0-798.0-734.0-777.0-831.0-934.0-812.0-977.0-1079.0608-1046.0-417.03873593141
Percentage of StockholdersEquity-22.7-21.6-19.1-14.4-14.8-8.2-6.2-4.5-7.8-8.1-8.0-11.5-12.8-13.4-13.0-9.2-9.5-9.9-9.6-9.5-9.4-9.9-9.3-10.9-19.7-32.5-45.020.4-217.5-23.122.4-1.2-4.05.4
Percentage of Assets-1.6-1.8-1.9-1.6-2.3-1.5-1.4-1.0-1.5-1.6-1.8-2.4-2.5-2.5-2.7-1.9-2.0-2.0-2.1-2.0-1.8-1.9-2.0-2.2-2.1-2.5-2.91.7-2.8-1.11.00.20.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value9042892383667383730760966129611160966080612061056091607760986569794677217425714571147071313629192392
Percentage of StockholdersEquity184.4171.4140.4105.485.864.753.254.159.162.061.264.570.572.969.275.988.6322.2248.81485.4393.9409.4-111.6-125.891.6
Percentage of Assets12.714.514.012.113.311.511.611.711.712.013.713.613.613.814.416.419.420.720.219.018.717.916.80.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value4.04.04.03.03.03.03.03.03.03.03.03.03.03.03.03.04.04.04.03.03.03.02.01.01.0
Percentage of StockholdersEquity0.10.10.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.20.10.60.20.2-0.1-0.00.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value8041239262645246365799197169075805069996668625254194736462134273457-3883.0-5015.0-5586.0-4863.0-5703.0-5956.0-5308.091
Percentage of StockholdersEquity16.423.844.164.674.784.884.380.378.071.466.766.062.756.852.539.638.6-162.1-168.1-1161.3-269.3-330.2211.9228.73.5
Percentage of Assets1.12.04.47.411.615.118.517.415.413.814.913.912.110.810.98.58.5-10.4-13.6-14.8-12.8-14.4-31.90.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-312007-12-31
Value-3832.0-3834.0-3897.0-3898.0-3899.0-3901.0-3599.0-3384.0-3022.0-2487.0-1993.0-1753.0-1720.0-1314.0-769.0-511.0-1610.0-367.0-38.0-35.0-31.0-31.0-28.0-26.0-15.0
Percentage of StockholdersEquity-78.1-73.6-65.4-55.7-45.8-41.4-31.2-29.9-29.3-25.4-19.9-18.5-19.9-15.8-8.7-5.9-18.0-15.3-1.3-7.3-1.7-1.81.01.1-0.6
Percentage of Assets-5.4-6.2-6.5-6.4-7.1-7.4-6.8-6.5-5.8-4.9-4.4-3.9-3.8-3.0-1.8-1.3-3.9-1.0-0.1-0.1-0.1-0.1-0.10.00.0
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value4000000.04000000.04000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.04000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.03000000.02000000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Additional Paid In Capital Common Stock

us-gaap:AdditionalPaidInCapitalCommonStock

us-gaap:AdditionalPaidInCapitalCommonStock


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value90428923836673837307609661296111609660806120610560916077609865916577656265697974796579567946794179387932772176207636766674257410735471597145714071357130711471107106710070713136
Percentage of AdditionalPaidInCapitalCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets12.714.514.012.113.311.511.611.711.712.013.713.613.613.814.415.515.515.816.419.819.719.719.419.020.220.320.720.019.920.620.219.919.619.419.018.818.418.718.718.217.917.517.916.8

us-gaap:AdditionalPaidInCapitalCommonStock dei:LegalEntity

ual:UnitedAirLinesInc


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value18511785683010.00.00.00.08459882284112331787232528663271357337183964464861386652691271567347743375407598759076367631762534443442343934353432343034283421
Percentage of AdditionalPaidInCapitalCommonStock2.01.31.00.90.40.20.00.00.01.49.813.513.820.329.335.343.649.854.446.649.858.477.283.887.190.295.297.598.799.1102.2103.0103.8106.548.248.248.248.248.248.248.248.4
Percentage of Assets0.30.20.10.10.10.00.00.00.00.21.31.81.92.84.25.56.87.98.99.29.811.515.015.917.618.319.719.619.620.420.620.520.420.79.29.18.99.09.08.88.68.6
Percentage of Assets ual:UnitedAirLinesInc0.30.20.10.10.10.00.00.00.00.21.31.81.92.84.25.56.87.98.99.29.811.515.015.917.518.319.319.319.420.120.420.220.020.316.615.915.215.818.818.217.917.4

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:RetainedEarningsAccumulatedDeficit


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value80412392626452463657991971690758050699966686203536746844621499143543536342753234358377034572634-2182.0-3375.0-3883.0-3911.0-4835.0-5624.0-5015.0-5155.0-5534.0-6003.0-5586.0-4965.0-4972.0-5311.0-4863.0-4725.0-5378.0-5916.0-5703.0-5956.0
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.12.04.47.411.615.118.517.415.413.814.913.812.010.610.911.710.38.58.513.210.89.38.56.3-5.5-8.6-10.4-10.3-12.6-15.1-13.6-13.8-14.8-16.3-14.8-13.1-12.8-13.9-12.8-12.1-13.5-14.6-14.4-31.9

us-gaap:RetainedEarningsAccumulatedDeficit dei:LegalEntity

ual:UnitedAirLinesInc


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value314835824939683586761030212353119091123010612102729807897182878218750468666048593755404575398736732850-1926.0-3119.0-3628.0-3619.0-4552.0-5322.0-4743.0-4897.0-5275.0-5758.0-6396.0-5829.0-5702.0-5631.0-5208.0-4953.0-5368.0-5489.0
Percentage of RetainedEarningsAccumulatedDeficit391.5289.1188.1151.1136.3128.9127.1131.2139.5151.6154.0158.1167.2176.9177.8150.4157.7171.0173.2104.1105.0105.8106.2108.288.392.493.492.594.194.694.695.095.395.9114.5117.4114.7106.0107.1104.899.896.2
Percentage of Assets4.45.88.311.215.819.423.522.821.521.022.921.920.118.819.417.616.214.614.813.711.39.99.06.8-4.9-8.0-9.7-9.5-11.8-14.3-12.9-13.1-14.1-15.6-17.0-15.4-14.7-14.7-13.7-12.7-13.5-13.9
Percentage of Assets ual:UnitedAirLinesInc4.45.88.311.215.819.423.522.821.521.022.921.920.118.819.417.616.214.614.813.711.39.99.06.8-4.9-8.0-9.5-9.4-11.7-14.1-12.7-12.9-13.9-15.4-30.7-27.0-25.3-25.9-28.5-26.3-28.0-28.0

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312013-03-272012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-312008-12-31
Value-1114.0-1126.0-1139.0-1009.0-1259.0-771.0-718.0-504.0-807.0-793.0-803.0-1089.0-1102.0-1114.0-1147.0-824.0-844.0-836.0-829.0-798.0-734.0-777.0-831.0-934.0-812.0-977.0-1079.0388589580608-493.0-569.0-1027.0-1027.0-1046.0-319.0-499.0-280.0-417.0-45.02427563873593
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-1.6-1.8-1.9-1.6-2.3-1.5-1.4-1.0-1.5-1.6-1.8-2.4-2.5-2.5-2.7-1.9-2.0-2.0-2.1-2.0-1.8-1.9-2.0-2.2-2.1-2.5-2.91.01.51.61.7-1.3-1.5-2.80.0-2.8-0.8-1.3-0.7-1.1-0.10.61.91.00.20.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax dei:LegalEntity

ual:UnitedAirLinesInc


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-312009-12-31
Value-1114.0-1126.0-1139.0-1009.0-1259.0-771.0-718.0-504.0-807.0-793.0-803.0-1089.0-1102.0-1114.0-1147.0-824.0-844.0-89.0-829.0-798.0-734.0-777.0-831.0-933.0-811.0-977.0-1079.0388589581608-493.0-569.0-1027.0-232.0-83.0-184.0-52.0-128.0-196.0-10.09135
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.010.6100.0100.0100.0100.0100.099.999.9100.0100.0100.0100.0100.2100.0100.0100.0100.022.226.036.918.630.7435.6-4.123.5100.0
Percentage of Assets-1.6-1.8-1.9-1.6-2.3-1.5-1.4-1.0-1.5-1.6-1.8-2.4-2.5-2.5-2.7-1.9-2.0-0.2-2.1-2.0-1.8-1.9-2.0-2.2-2.1-2.5-2.91.01.51.61.7-1.3-1.5-2.8-0.6-0.2-0.5-0.1-0.3-0.5-0.00.20.2
Percentage of Assets ual:UnitedAirLinesInc-1.6-1.8-1.9-1.6-2.3-1.5-1.4-1.0-1.5-1.6-1.8-2.4-2.5-2.5-2.7-1.9-2.0-0.2-2.1-2.0-1.8-1.9-2.0-2.2-2.1-2.5-2.81.01.51.51.6-1.3-1.5-2.7-1.1-0.4-0.8-0.2-0.7-1.0-0.10.50.0

Treasury Stock Value

us-gaap:TreasuryStockValue

us-gaap:TreasuryStockValue


Treasury
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value38323834389738983899390135993384302224871993175317201314769179112368165114064380931131610109082657636723747473838383835323232313131313128
Percentage of TreasuryStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets5.46.26.56.47.17.46.86.55.84.94.43.93.83.01.84.22.92.01.310.19.47.73.92.62.11.51.00.60.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.1

Stock Issued During Period Value New Issues

us-gaap:StockIssuedDuringPeriodValueNewIssues

us-gaap:StockIssuedDuringPeriodValueNewIssues


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-30
Value0.05329680.01135
Percentage of StockIssuedDuringPeriodValueNewIssues0.0100.0100.00.0100.0
Percentage of Assets0.00.00.00.00.0

us-gaap:StockIssuedDuringPeriodValueNewIssues dei:LegalEntity

ual:UnitedAirLinesInc


Stock
Period End2021-06-302021-03-312020-06-30
Value0.05321135
Percentage of StockIssuedDuringPeriodValueNewIssues0.0100.0100.0
Percentage of Assets0.00.00.0
Percentage of Assets ual:UnitedAirLinesInc0.00.00.0

us-gaap:StockIssuedDuringPeriodValueNewIssues dei:LegalEntity, us-gaap:StatementEquityComponents

ual:UnitedAirLinesInc, us-gaap:ReceivablesFromStockholder


Stock
Period End2021-06-302021-03-312020-06-30
Value0.05321135
Percentage of StockIssuedDuringPeriodValueNewIssues0.0100.0100.0
Percentage of Assets0.00.00.0
Percentage of Assets ual:UnitedAirLinesInc us-gaap:ReceivablesFromStockholder0.00.00.0

us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-30
Value0.05329670.01135
Percentage of StockIssuedDuringPeriodValueNewIssues0.0100.099.90.0100.0
Percentage of Assets0.00.00.00.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.0

Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue


Adjustments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value6832173820221718171415161415
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue dei:LegalEntity

ual:UnitedAirLinesInc


Adjustments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value6832173820221718171415161415
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets ual:UnitedAirLinesInc0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue dei:LegalEntity, us-gaap:StatementEquityComponents

ual:UnitedAirLinesInc, us-gaap:AdditionalPaidInCapital


Adjustments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value6832173820221718171415161415
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets ual:UnitedAirLinesInc us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


Adjustments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value6832173820221718171415161415
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2675447-2177.0-1889.0-130.06311811103271019151084905246617097895771464694-334.0237114839390-238.09591242653857531005106445874482
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax48.913.9-63.8-75.9-8.80.810.89.723.820.010.38.222.918.98.35.814.28.0-3.62.311.54.51.0-2.49.61.43.03.87.712.31.38.216.911.4

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity

ual:UnitedAirLinesInc


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value2675426-2177.0-1890.0-123.04511811102271018861083905246616927895761463686-333.02361149389139-489.01044168-20.03962567860.0445
Percentage of NetCashProvidedByUsedInOperatingActivities100.095.3100.0100.194.671.4100.099.9100.098.599.9100.0100.099.0100.099.899.998.899.799.6100.199.0154.4205.5108.9135.5-7.5102.934.078.20.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax48.913.2-63.8-75.9-8.30.610.89.723.819.710.38.222.918.78.35.814.27.9-3.62.311.54.51.6-4.910.52.0-0.23.92.69.60.08.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc48.913.2-63.8-75.9-8.30.610.89.723.819.710.38.222.918.78.35.814.27.9-3.62.311.54.52.7-8.619.13.5-0.46.84.616.80.08.2

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-781.0-329.040770812-1572.0-1329.0-795.0-856.0-1580.0-1852.0-886.0-1022.0-695.0-849.0-1276.0-905.0-427.0-723.0-466.0-402.0-431.0-1152.0-230.0-213.0-362.0-517.0-453.0-509.0-320.03472-57.0-19.0-76.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-14.3-10.21.230.955.1-19.7-12.2-7.0-7.5-16.5-17.7-8.1-9.5-7.7-9.0-12.9-8.8-4.9-7.8-4.6-4.0-4.9-13.2-2.3-2.1-4.2-5.8-4.5-5.2-3.941.0-1.1-0.4-1.8

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity

ual:UnitedAirLinesInc


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-781.0-329.040770812-1572.0-1329.0-795.0-856.0-1580.0-1852.0-886.0-1022.0-695.0-849.0-1276.0-905.0-427.0-723.0-466.0-403.0-431.0-235.0-191.0-134.0-121.0-401.0-134.0-262.0-135.0-75.0-57.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.2100.020.483.062.933.477.629.651.542.2-2.2100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-14.3-10.21.230.955.1-19.7-12.2-7.0-7.5-16.5-17.7-8.1-9.5-7.7-9.0-12.9-8.8-4.9-7.8-4.6-4.0-4.9-2.7-1.9-1.3-1.4-4.5-1.3-2.7-1.6-0.9-1.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc-14.3-10.21.230.955.1-19.7-12.2-7.0-7.5-16.5-17.7-8.1-9.5-7.7-9.0-12.9-8.8-4.9-7.7-4.6-4.0-4.9-4.6-3.4-2.4-2.5-7.9-2.3-4.7-2.9-1.5-1.1

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value62761278481790523822189-47.0-571.0-479.0-183.0-159.0-284.0-963.0-95.0-328.0177-144.0-478.034221-141.0-1194.0703-489.0-266.0-402.0-486.0-467.0-890.0-589.0-447.0-356.053568
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax114.739.714.1317.6161.527.4-0.4-5.0-4.2-1.9-1.5-2.6-8.9-1.1-3.51.8-1.4-5.53.70.2-1.4-13.78.1-4.9-2.7-4.7-5.4-4.6-9.1-7.2-5.3-6.610.41.6

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity

ual:UnitedAirLinesInc


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value62761299481790623812207-47.0-570.0-479.0-154.0-158.0-284.0-963.0-78.0-328.0178-143.0-470.034221-141.0-1191.0-143.0-391.0-172.0-167.0-191.0-299.0-693.0-510.0-192.0-356.0
Percentage of NetCashProvidedByUsedInFinancingActivities100.0101.6100.0100.0100.0100.8100.099.8100.084.299.4100.0100.082.1100.0100.699.398.3100.0100.0100.099.7-20.380.064.741.539.364.077.986.643.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax114.740.314.1317.6161.427.7-0.4-5.0-4.2-1.6-1.5-2.6-8.9-0.9-3.51.8-1.4-5.43.70.2-1.4-13.7-1.6-3.9-1.7-1.9-2.1-2.9-7.1-6.2-2.3-6.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc114.740.314.1317.6161.427.7-0.4-5.0-4.2-1.6-1.5-2.6-8.9-0.9-3.51.8-1.4-5.43.70.2-1.4-13.7-2.8-6.9-3.1-3.5-3.8-5.1-12.4-10.9-3.9-6.6

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value81701396-1656.067863064680-195.0-263.01375152-927.0-265.0481919-388.0-522.0
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax149.343.3-48.5272.6207.78.5-1.8-2.312.11.6-8.8-2.44.510.2-4.1-5.3

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect dei:LegalEntity

ual:UnitedAirLinesInc


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value81701396-1656.067863070680-195.0-263.01375152-927.0-265.0481919-388.0-522.0
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect100.0100.0100.0100.0100.2100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax149.343.3-48.5272.6208.18.5-1.8-2.312.11.6-8.8-2.44.510.2-4.1-5.3
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc149.343.3-48.5272.6208.18.5-1.8-2.312.11.6-8.8-2.44.510.2-4.1-5.3

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization

us-gaap:DepreciationDepletionAndAmortization


Depreciation
Period End2021-06-302021-03-312020-06-302020-03-31
Value620623618615
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0

us-gaap:DepreciationDepletionAndAmortization dei:LegalEntity

ual:UnitedAirLinesInc


Depreciation
Period End2021-06-302021-03-312020-06-302020-03-31
Value620623618615
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value2675447-2177.0-1889.0-130.06311811103271019151084905246617097895771464694-334.0237114839390-238.09591242653857531005106445874482
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax48.913.9-63.8-75.9-8.80.810.89.723.820.010.38.222.918.98.35.814.28.0-3.62.311.54.51.0-2.49.61.43.03.87.712.31.38.216.911.4

us-gaap:NetCashProvidedByUsedInOperatingActivities dei:LegalEntity

ual:UnitedAirLinesInc


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value2675426-2177.0-1890.0-123.04511811102271018861083905246616927895761463686-333.02361149389139-489.01044168-20.03962567860.0445
Percentage of NetCashProvidedByUsedInOperatingActivities100.095.3100.0100.194.671.4100.099.9100.098.599.9100.0100.099.0100.099.899.998.899.799.6100.199.0154.4205.5108.9135.5-7.5102.934.078.20.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax48.913.2-63.8-75.9-8.30.610.89.723.819.710.38.222.918.78.35.814.27.9-3.62.311.54.51.6-4.910.52.0-0.23.92.69.60.08.2
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc48.913.2-63.8-75.9-8.30.610.89.723.819.710.38.222.918.78.35.814.27.9-3.62.311.54.52.7-8.619.13.5-0.46.84.616.80.08.2

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-434.0-1357.0-1897.0-1841.0-1627.0-1704.064110241052292462836684147580637818963979655883138234816119350828924789-609.0140379469-417.0-620.06.0339-448.0-138.0653538-213.0-325.0387273-82.0
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-7.9-42.1-55.6-74.0-110.3-21.45.99.09.23.04.47.66.31.66.16.48.21.14.49.76.33.89.146.712.05.90.38.77.6-7.01.53.74.7-4.8-7.10.13.4-5.2-1.56.45.5-2.6-3.87.15.3-1.9

us-gaap:NetIncomeLoss dei:LegalEntity

ual:UnitedAirLinesInc


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value-434.0-1357.0-1896.0-1841.0-1626.0-1704.0642102410522934638376841475976378189739796558831482347761193509-8.0933769-580.0154378484-362.0-567.0-127.0-71.0-423.0-255.0415281-160.0-207.0399281
Percentage of NetIncomeLoss100.0100.099.9100.099.9100.0100.2100.0100.0100.3100.2100.1100.0100.0102.9100.0100.0101.0100.0100.0100.0100.3100.099.2100.0100.2-28.6101.097.595.2110.099.7103.286.891.5-2116.7-20.994.4184.863.652.275.163.7103.1102.9
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-7.9-42.1-55.6-74.0-110.2-21.45.99.09.23.14.47.66.31.66.36.48.21.24.49.76.33.89.146.312.05.9-0.18.87.4-6.71.73.74.8-4.2-6.5-1.3-0.7-4.9-2.94.12.9-2.0-2.47.45.4
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc-7.9-42.1-55.6-74.0-110.2-21.45.99.09.23.14.47.66.31.66.36.48.21.24.49.76.33.89.146.312.05.9-0.18.87.4-6.71.73.74.8-4.1-11.2-2.2-1.3-8.9-5.07.15.0-3.4-4.27.45.4

us-gaap:NetIncomeLoss dei:LegalEntity, us-gaap:StatementEquityComponents

ual:UnitedAirLinesInc, us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-434.0-1357.0-1896.0-1841.0-1626.0-1704.064210241052293469834683145
Percentage of NetIncomeLoss100.0100.099.9100.099.9100.0100.2100.0100.0100.3101.599.899.998.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-7.9-42.1-55.6-74.0-110.2-21.45.99.09.23.14.57.66.31.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-434.0-1357.0-1897.0-1841.0-1627.0-1704.064110241052292468833683145
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0101.399.699.998.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-7.9-42.1-55.6-74.0-110.3-21.45.99.09.23.04.57.66.31.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value-781.0-329.040770812-1572.0-1329.0-795.0-856.0-1580.0-1852.0-886.0-1022.0-695.0-849.0-1276.0-905.0-427.0-723.0-466.0-402.0-431.0-1152.0-230.0-213.0-362.0-517.0-453.0-509.0-320.03472-57.0-19.0-76.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-14.3-10.21.230.955.1-19.7-12.2-7.0-7.5-16.5-17.7-8.1-9.5-7.7-9.0-12.9-8.8-4.9-7.8-4.6-4.0-4.9-13.2-2.3-2.1-4.2-5.8-4.5-5.2-3.941.0-1.1-0.4-1.8

us-gaap:NetCashProvidedByUsedInInvestingActivities dei:LegalEntity

ual:UnitedAirLinesInc


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-781.0-329.040770812-1572.0-1329.0-795.0-856.0-1580.0-1852.0-886.0-1022.0-695.0-849.0-1276.0-905.0-427.0-723.0-466.0-403.0-431.0-235.0-191.0-134.0-121.0-401.0-134.0-262.0-135.0-75.0-57.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.2100.020.483.062.933.477.629.651.542.2-2.2100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax-14.3-10.21.230.955.1-19.7-12.2-7.0-7.5-16.5-17.7-8.1-9.5-7.7-9.0-12.9-8.8-4.9-7.8-4.6-4.0-4.9-2.7-1.9-1.3-1.4-4.5-1.3-2.7-1.6-0.9-1.1
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc-14.3-10.21.230.955.1-19.7-12.2-7.0-7.5-16.5-17.7-8.1-9.5-7.7-9.0-12.9-8.8-4.9-7.7-4.6-4.0-4.9-4.6-3.4-2.4-2.5-7.9-2.3-4.7-2.9-1.5-1.1

Payments To Acquire Productive Assets

us-gaap:PaymentsToAcquireProductiveAssets

us-gaap:PaymentsToAcquireProductiveAssets


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value86144497-368.039195911928698581609158585875597910981120108969188068983881676367311012106603925893647655784463751242222286266190160145205159887351
Percentage of PaymentsToAcquireProductiveAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireProductiveAssets dei:LegalEntity

ual:UnitedAirLinesInc


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value86144497-368.039195911928698581609158585875597910981120108969188068983881676367311012106603925893647655784463754001461321131321109712510688
Percentage of PaymentsToAcquireProductiveAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.032.265.846.242.569.568.866.961.066.7100.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value62761278481790523822189-47.0-571.0-479.0-183.0-159.0-284.0-963.0-95.0-328.0177-144.0-478.034221-141.0-1194.0703-489.0-266.0-402.0-486.0-467.0-890.0-589.0-447.0-356.053568
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax114.739.714.1317.6161.527.4-0.4-5.0-4.2-1.9-1.5-2.6-8.9-1.1-3.51.8-1.4-5.53.70.2-1.4-13.78.1-4.9-2.7-4.7-5.4-4.6-9.1-7.2-5.3-6.610.41.6

us-gaap:NetCashProvidedByUsedInFinancingActivities dei:LegalEntity

ual:UnitedAirLinesInc


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value62761299481790623812207-47.0-570.0-479.0-154.0-158.0-284.0-963.0-78.0-328.0178-143.0-470.034221-141.0-1191.0-143.0-391.0-172.0-167.0-191.0-299.0-693.0-510.0-192.0-356.0
Percentage of NetCashProvidedByUsedInFinancingActivities100.0101.6100.0100.0100.0100.8100.099.8100.084.299.4100.0100.082.1100.0100.699.398.3100.0100.0100.099.7-20.380.064.741.539.364.077.986.643.0100.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax114.740.314.1317.6161.427.7-0.4-5.0-4.2-1.6-1.5-2.6-8.9-0.9-3.51.8-1.4-5.43.70.2-1.4-13.7-1.6-3.9-1.7-1.9-2.1-2.9-7.1-6.2-2.3-6.6
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax ual:UnitedAirLinesInc114.740.314.1317.6161.427.7-0.4-5.0-4.2-1.6-1.5-2.6-8.9-0.9-3.51.8-1.4-5.43.70.2-1.4-13.7-2.8-6.9-3.1-3.5-3.8-5.1-12.4-10.9-3.9-6.6

Proceeds From Issuance Of Long Term Debt

us-gaap:ProceedsFromIssuanceOfLongTermDebt

us-gaap:ProceedsFromIssuanceOfLongTermDebt


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value97801336302011355132134873811335064640824612696646980384755298435334246038512810025578224814760429941110910350.00.08610.00.011032910.06861309
Percentage of ProceedsFromIssuanceOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.00.0100.0100.0100.00.0100.0100.0

us-gaap:ProceedsFromIssuanceOfLongTermDebt dei:LegalEntity

ual:UnitedAirLinesInc


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312010-12-312010-09-30
Value97801336302011355132134873811335064640824612696646980384755298435334246038512810025578224814760429941110910350.00.0860.00.0
Percentage of ProceedsFromIssuanceOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.00.00.0

us-gaap:ProceedsFromIssuanceOfLongTermDebt dei:LegalEntity, us-gaap:DebtInstrument, us-gaap:LongtermDebtType

ual:UnitedAirLinesInc, ual:ClassAAPassThroughCertificatesIssuedSeptember2019, ual:PassThroughCertificates


Proceeds
Period End2020-09-302020-06-302020-03-31
Value0.00.0189
Percentage of ProceedsFromIssuanceOfLongTermDebt0.00.054.3

ual:UnitedAirLinesInc, ual:ClassAPassThroughCertificatesIssuedFebruary2021, ual:PassThroughCertificates


Proceeds
Period End2021-06-302021-03-31
Value0.0600
Percentage of ProceedsFromIssuanceOfLongTermDebt0.044.9

ual:UnitedAirLinesInc, ual:ClassAPassThroughCertificatesIssuedSeptember2019, ual:PassThroughCertificates


Proceeds
Period End2020-09-302020-06-302020-03-31
Value0.00.077
Percentage of ProceedsFromIssuanceOfLongTermDebt0.00.022.1

ual:UnitedAirLinesInc, ual:ClassBPassThroughCertificatesIssuedSeptember2019, ual:PassThroughCertificates


Proceeds
Period End2020-09-302020-06-302020-03-31
Value0.00.062
Percentage of ProceedsFromIssuanceOfLongTermDebt0.00.017.8

us-gaap:ProceedsFromIssuanceOfLongTermDebt dei:LegalEntity, us-gaap:LongtermDebtType

ual:UnitedAirLinesInc, ual:PassThroughCertificates


Proceeds
Period End2020-09-302020-06-302020-03-312018-09-30
Value0.00.03280.0
Percentage of ProceedsFromIssuanceOfLongTermDebt0.00.094.30.0

us-gaap:ProceedsFromIssuanceOfLongTermDebt us-gaap:DebtInstrument, us-gaap:LongtermDebtType

ual:CARESActCreditAgreement, us-gaap:LineOfCredit


Proceeds
Period End2020-09-28
Value520
Percentage of ProceedsFromIssuanceOfLongTermDebt0.0

ual:MileagePlusMPTermLoanFacility, us-gaap:LineOfCredit


Proceeds
Period End2020-07-02
Value3000
Percentage of ProceedsFromIssuanceOfLongTermDebt0.0

ual:USDepartmentOfTreasuryTermLoan, us-gaap:LineOfCredit


Proceeds
Period End2020-09-28
Value520
Percentage of ProceedsFromIssuanceOfLongTermDebt0.0

us-gaap:ProceedsFromIssuanceOfLongTermDebt us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType

ual:TermLoanFacility, us-gaap:LineOfCredit, us-gaap:SubsequentEvent


Proceeds
Period End2020-07-02
Value3000
Percentage of ProceedsFromIssuanceOfLongTermDebt0.0

us-gaap:ProceedsFromIssuanceOfLongTermDebt us-gaap:LongtermDebtType

ual:NotesPayableSecuredTermLoansAndAircraftFinancing


Proceeds
Period End2021-03-31
Value1400
Percentage of ProceedsFromIssuanceOfLongTermDebt104.8

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt

us-gaap:RepaymentsOfLongTermDebt


Repayments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value350356934194412882355142532232502082251105189179197210315304458226227650209102329650210892996132202284961241234462217479442448949528494255701204
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RepaymentsOfLongTermDebt dei:LegalEntity

ual:UnitedAirLinesInc


Repayments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value350356934194412882355142532232502082251105189179197210315304458226227650209102329650210892996132202284961241104365122147140279640397139255
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.044.479.056.230.731.762.367.475.228.1100.0

Payments For Repurchase Of Common Stock

us-gaap:PaymentsForRepurchaseOfCommonStock

us-gaap:PaymentsForRepurchaseOfCommonStock


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value0.00.00.035321436954951322541440529553579454258172260790139252326525019592
Percentage of PaymentsForRepurchaseOfCommonStock0.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Effective Income Tax Rate Continuing Operations

us-gaap:EffectiveIncomeTaxRateContinuingOperations

us-gaap:EffectiveIncomeTaxRateContinuingOperations


Effective
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-31
Value23.022.521.10.1880.1940.2410.2230.2040.2120.2020.2030.350.3580.3380.360.3690.366
Percentage of EffectiveIncomeTaxRateContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

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

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber


Share
Period End2020-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value0.73.04.6076.946116.406
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber100.0100.0100.0100.0100.0100.0

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

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice


Share
Period End2020-12-312013-12-312012-12-312011-12-312010-12-312009-12-31
Value82.1231.6325.623.821.722.42
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice100.0100.0100.0100.0100.0100.0

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

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod

ual:PerformanceBasedRestrictedStockUnitsRSUs


Share
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value01600000.0000300000.000
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod0.0100.00.00.00.0100.00.00.0

ual:TimeVestedRestrictedStockUnitsRSUs


Share
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value100000.01200000.0100000.001700000.0400000.0100000.00
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod0.075.00.00.00.0133.30.00.0

us-gaap:RestrictedStockUnitsRSU


Share
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302017-12-312017-09-302016-12-312016-09-302016-06-302016-03-312015-12-312015-03-312014-02-282013-02-282012-02-29
Value100000.02800000.0100000.001700000.0700000.0100000.00100000.0001100000.00800000.0700000.0300000.0500000.0500000.0600000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod0.0175.00.00.00.0233.30.00.00.00.00.00.00.00.00.00.00.00.00.0

Deferred Tax Assets Net

us-gaap:DeferredTaxAssetsNet

us-gaap:DeferredTaxAssetsNet


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-31
Value66104060286430095942746938413943479249525229
Percentage of DeferredTaxAssetsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsNet dei:LegalEntity

ual:UnitedAirLinesInc


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value6582403328362982589974273805391028072995
Percentage of DeferredTaxAssetsNet99.699.399.099.199.399.499.199.258.660.5

Unrecognized Tax Benefits

us-gaap:UnrecognizedTaxBenefits

us-gaap:UnrecognizedTaxBenefits


Unrecognized
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-312010-12-312009-12-312008-12-31
Value5753392174249.0141924321620
Percentage of UnrecognizedTaxBenefits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Deferred Tax Assets Valuation Allowance

us-gaap:DeferredTaxAssetsValuationAllowance

us-gaap:DeferredTaxAssetsValuationAllowance


Deferred
Period End2021-03-312020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312015-09-302014-12-312013-12-312012-12-312011-12-312010-12-31
Value2422475859636848320047513806460341374171
Percentage of DeferredTaxAssetsValuationAllowance100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsValuationAllowance dei:LegalEntity

ual:UnitedAirLinesInc


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value24758596368484721377630682614
Percentage of DeferredTaxAssetsValuationAllowance100.0100.0100.0100.0100.0100.099.499.266.763.2

ual:CapitalContributionsToParent dei:LegalEntity

ual:CapitalContributionsToParent

ual:UnitedAirLinesInc


Capital
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.00.00.034221536353652823934407569
Percentage of CapitalContributionsToParent0.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:CapitalContributionsToParent dei:LegalEntity, us-gaap:StatementEquityComponents

ual:UnitedAirLinesInc, us-gaap:AdditionalPaidInCapital


Capital
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.00.00.012171810252823934407569
Percentage of CapitalContributionsToParent0.00.00.03.57.95.019.0100.0100.0100.0100.0100.0

ual:UnitedAirLinesInc, us-gaap:RetainedEarnings


Capital
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value0.00.00.0330198345434
Percentage of CapitalContributionsToParent0.00.00.096.592.195.081.0

ual:DebtInstrumentVariableRateFloor dei:LegalEntity, us-gaap:CreditFacility, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType, us-gaap:VariableRate

ual:DebtInstrumentVariableRateFloor

ual:UnitedAirLinesInc, us-gaap:RevolvingCreditFacility, us-gaap:SecuredDebt, us-gaap:SubsequentEvent, us-gaap:LondonInterbankOfferedRateLIBOR


Debt
Period End2020-07-02
Value0
Percentage of DebtInstrumentVariableRateFloor0.0

ual:DebtInstrumentVariableRateFloor us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType, us-gaap:VariableRate

ual:TermLoanFacility, us-gaap:LineOfCredit, us-gaap:SubsequentEvent, us-gaap:LondonInterbankOfferedRateLIBOR


Debt
Period End2020-07-02
Value0.01
Percentage of DebtInstrumentVariableRateFloor0.0

ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSettlementExcludingRestructuring us-gaap:RetirementPlanType

ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSettlementExcludingRestructuring

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-09-302020-06-302019-09-302019-06-30
Value-5000000.0-11000000.0-2000000.0-3000000.0
Percentage of DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSettlementExcludingRestructuring100.0100.0100.0100.0

ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSettlementRestructuring us-gaap:RetirementPlanType

ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSettlementRestructuring

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312020-09-302020-06-302019-06-30
Value-40000000.0-319000000.0-71000000.00
Percentage of DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSettlementRestructuring100.0100.0100.00.0

ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSettlementRestructuringAndSpecialAndContractualTerminationBenefits

ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSettlementRestructuringAndSpecialAndContractualTerminationBenefits


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-06-30
Value0-46000000.0-41000000.0-415000000.0-231000000.00
Percentage of DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSettlementRestructuringAndSpecialAndContractualTerminationBenefits0.0100.0100.0100.0100.00.0

ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSpecialAndContractualTerminationBenefits us-gaap:RestructuringCostAndReserve, us-gaap:RestructuringPlan

ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSpecialAndContractualTerminationBenefits

us-gaap:EmployeeSeverance, ual:VoluntarySeparationLeaveVSLPrograms


Defined
Period End2021-06-302021-03-31
Value0.046
Percentage of DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSpecialAndContractualTerminationBenefits0.0100.0

ual:DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSpecialAndContractualTerminationBenefits us-gaap:RetirementPlanType

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-06-30
Value0.0-46.00.0-76.0-125.00.0
Percentage of DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSpecialAndContractualTerminationBenefits0.0-100.00.00.00.00.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312020-09-302020-06-302019-06-30
Value0.0-19.0-35.00.0
Percentage of DefinedBenefitPlanNetPeriodicBenefitCostCreditGainLossDueToSpecialAndContractualTerminationBenefits0.00.00.00.0

ual:FrequentFlyerMileageMilesAwardedInPeriod us-gaap:ProductOrService

ual:FrequentFlyerMileageMilesAwardedInPeriod

ual:FrequentFlyerProgram


Frequent
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value360272280268228559670662682607625616607
Percentage of FrequentFlyerMileageMilesAwardedInPeriod100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:GainLossOnContractTerminationAndNaturalDisaster

ual:GainLossOnContractTerminationAndNaturalDisaster


Gain
Period End2021-03-31
Value-16000000.0
Percentage of GainLossOnContractTerminationAndNaturalDisaster100.0

ual:GainLossOnDebtExtinguishmentAndModificationNonoperating

ual:GainLossOnDebtExtinguishmentAndModificationNonoperating


Gain
Period End2021-06-30
Value-62000000.0
Percentage of GainLossOnDebtExtinguishmentAndModificationNonoperating100.0

ual:GainLossOnFinancialInstrumentsNonOperating

ual:GainLossOnFinancialInstrumentsNonOperating


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value147-22.0101159.0-319.0812134175629-135.045
Percentage of GainLossOnFinancialInstrumentsNonOperating100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:GainLossOnFinancialInstrumentsNonOperating us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

ual:AVHDerivativeAssets


Gain
Period End2020-09-30
Value0.0
Percentage of GainLossOnFinancialInstrumentsNonOperating0.0

ual:Azul


Gain
Period End2021-06-30
Value57
Percentage of GainLossOnFinancialInstrumentsNonOperating38.8

ual:ClearSecureInc


Gain
Period End2021-06-30
Value90
Percentage of GainLossOnFinancialInstrumentsNonOperating61.2

ual:InvestmentsExcludingAVHDerivativeAssets


Gain
Period End2020-12-312020-09-30
Value10115
Percentage of GainLossOnFinancialInstrumentsNonOperating100.0100.0

ual:GainLossOnNetCharges

ual:GainLossOnNetCharges


Gain
Period End2021-06-30
Value61
Percentage of GainLossOnNetCharges100.0

ual:GainLossOnSaleOfOtherAssetsAndOtherMiscellaneousCharges

ual:GainLossOnSaleOfOtherAssetsAndOtherMiscellaneousCharges


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-61000000.0-16000000.0-5000000.0-25000000.03000000.0-13000000.0-26000000.0-25000000.0-4000000.0-4000000.02000000.03000000.0-7000000.0-3000000.0-6000000.0-12000000.0-3000000.0-14000000.0-19000000.0-18000000.0-6000000.0-8000000.0
Percentage of GainLossOnSaleOfOtherAssetsAndOtherMiscellaneousCharges100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:IncomeTaxExpenseBenefitSpecialCharges

ual:IncomeTaxExpenseBenefitSpecialCharges


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value20329129148241-14.0-11.0-2.0-8.00.0-55.03.0-29.0-9.0-11.0-18.0-16.0-18.012-16.0-153.0-72.0
Percentage of IncomeTaxExpenseBenefitSpecialCharges100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:LeaseConversionsFromOperatingLeaseRecordedPropertyPlantAndEquipment

ual:LeaseConversionsFromOperatingLeaseRecordedPropertyPlantAndEquipment


Lease
Period End2021-06-302021-03-312020-06-302020-03-31
Value372231439
Percentage of LeaseConversionsFromOperatingLeaseRecordedPropertyPlantAndEquipment100.0100.0100.0100.0

ual:LeaseConversionsFromOperatingLeaseRecordedPropertyPlantAndEquipment dei:LegalEntity

ual:UnitedAirLinesInc


Lease
Period End2021-06-302021-03-312020-06-302020-03-31
Value372231439
Percentage of LeaseConversionsFromOperatingLeaseRecordedPropertyPlantAndEquipment100.0100.0100.0100.0

ual:NonTravelMilesRedemptionFrequentFlyerDeferredRevenue us-gaap:ProductOrService

ual:NonTravelMilesRedemptionFrequentFlyerDeferredRevenue

ual:FrequentFlyerProgram


Non
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value17151616122534343336473836
Percentage of NonTravelMilesRedemptionFrequentFlyerDeferredRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:NumberOfEmployeesNotifiedOfPlansForWorkforceReduction

ual:NumberOfEmployeesNotifiedOfPlansForWorkforceReduction


Number
Period End2020-07-31
Value36000.0
Percentage of NumberOfEmployeesNotifiedOfPlansForWorkforceReduction100.0

ual:OtherComprehensiveIncomeInvestmentsAndOtherNetOfTax

ual:OtherComprehensiveIncomeInvestmentsAndOtherNetOfTax


Other
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302013-12-312013-09-30
Value0.0-1.013-12.00.0-1.03.03.0-8.01.00.03.0-11.017-12.01.00.0-1.0-2.0-6.0-10.014-2.01.0-5.05.0-5.0
Percentage of OtherComprehensiveIncomeInvestmentsAndOtherNetOfTax0.0100.0100.0100.00.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:OtherComprehensiveIncomeInvestmentsAndOtherNetOfTax dei:LegalEntity

ual:UnitedAirLinesInc


Other
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value0.0-1.013-12.00.0-1.03.03.0-8.01.00.03.0-11.017-12.01.00.0-1.0-3.0-6.0-9.014-2.01.0-6.01.05.0-5.0
Percentage of OtherComprehensiveIncomeInvestmentsAndOtherNetOfTax0.0100.0100.0100.00.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.00.0100.0150.0100.090.0100.0100.0100.0120.00.0100.0100.0

ual:PaymentsOfDividendsToParentCompany dei:LegalEntity

ual:PaymentsOfDividendsToParentCompany

ual:UnitedAirLinesInc


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value0.00.00.035321436954951322541440529553579454258172260790139252426425019592
Percentage of PaymentsOfDividendsToParentCompany0.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:PercentageOfEmployeesRepresentedByLaborOrganizations dei:LegalEntity

ual:PercentageOfEmployeesRepresentedByLaborOrganizations

ual:UnitedAirLinesInc


Percentage
Period End2021-06-302021-03-312020-12-31
Value085.0-1.0
Percentage of PercentageOfEmployeesRepresentedByLaborOrganizations0.0100.0100.0

ual:ProceedsFromGovernmentAssistance

ual:ProceedsFromGovernmentAssistance


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-30
Value320026000.051004500
Percentage of ProceedsFromGovernmentAssistance100.0100.00.0100.0100.0

ual:ProceedsFromGovernmentAssistance us-gaap:SubsequentEventType

us-gaap:SubsequentEvent


Proceeds
Period End2021-02-25
Value1300
Percentage of ProceedsFromGovernmentAssistance0.0

ual:ProceedsFromGovernmentAssistanceGrants

ual:ProceedsFromGovernmentAssistanceGrants


Proceeds
Period End2021-03-312020-12-312020-09-302020-06-30
Value18000.036003200
Percentage of ProceedsFromGovernmentAssistanceGrants100.00.0100.0100.0

ual:RestructuringAndRelatedCostNumberOfEmployeesVoluntarilySeparated us-gaap:RestructuringCostAndReserve, us-gaap:RestructuringPlan

ual:RestructuringAndRelatedCostNumberOfEmployeesVoluntarilySeparated

us-gaap:EmployeeSeverance, ual:VoluntarySeparationLeaveVSLPrograms


Restructuring
Period End2021-06-302021-03-31
Value04500.0
Percentage of RestructuringAndRelatedCostNumberOfEmployeesVoluntarilySeparated0.0100.0

ual:RestructuringProgramsOneTimeContributionPerEmployee ual:EmployeeClassification, us-gaap:RestructuringCostAndReserve, us-gaap:RestructuringPlan

ual:RestructuringProgramsOneTimeContributionPerEmployee

ual:FullTimeEmployees, us-gaap:EmployeeSeverance, ual:VoluntarySeparationLeaveVSLPrograms


Restructuring
Period End2021-03-31
Value125000.0
Percentage of RestructuringProgramsOneTimeContributionPerEmployee100.0

ual:PartTimeEmployees, us-gaap:EmployeeSeverance, ual:VoluntarySeparationLeaveVSLPrograms


Restructuring
Period End2021-03-31
Value75000.0
Percentage of RestructuringProgramsOneTimeContributionPerEmployee60.0

ual:SpecialChargesAndLossesOnFinancialInstrumentsNonOperatingBeforeTax

ual:SpecialChargesAndLossesOnFinancialInstrumentsNonOperatingBeforeTax


Special
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-85.068-60.04002221079496.0371.0245-12.0264-5.0
Percentage of SpecialChargesAndLossesOnFinancialInstrumentsNonOperatingBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:SpecialChargesAndLossesOnFinancialInstrumentsOperatingAndNonoperatingBeforeTax

ual:SpecialChargesAndLossesOnFinancialInstrumentsOperatingAndNonoperatingBeforeTax


Special
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value-1033.0-1309.0-209.0-681.0-1227.01079496.037
Percentage of SpecialChargesAndLossesOnFinancialInstrumentsOperatingAndNonoperatingBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:SpecialItemsNetOfIncomeTaxBenefits

ual:SpecialItemsNetOfIncomeTaxBenefits


Special
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-830.0-1018.0-180.0-533.0-986.01065384.0291.0185-9.010031-172.032283316129272126-3003.013718370
Percentage of SpecialItemsNetOfIncomeTaxBenefits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:TravelMilesRedemptionFrequentFlyerDeferredRevenue us-gaap:ProductOrService

ual:TravelMilesRedemptionFrequentFlyerDeferredRevenue

ual:FrequentFlyerProgram


Travel
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value2671231248734322579607589438560580519
Percentage of TravelMilesRedemptionFrequentFlyerDeferredRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:UnusualOrInfrequentEventPayrollTaxesDeferredUnderCARESAct

ual:UnusualOrInfrequentEventPayrollTaxesDeferredUnderCARESAct


Unusual
Period End2020-12-31
Value59
Percentage of UnusualOrInfrequentEventPayrollTaxesDeferredUnderCARESAct100.0

ual:UnusualOrInfrequentItemsPercentOfCapacityCut

ual:UnusualOrInfrequentItemsPercentOfCapacityCut


Unusual
Period End2021-06-302021-03-312020-09-302020-06-30
Value46.0-54.070.00.88
Percentage of UnusualOrInfrequentItemsPercentOfCapacityCut100.0100.0100.0100.0

ual:UnusualOrInfrequentItemsPercentOfCapacityCut us-gaap:StatementScenario

srt:ScenarioForecast


Unusual
Period End2021-09-302021-06-302021-03-312020-12-312020-09-302020-05-31
Value26.045.051.055.00.650.9
Percentage of UnusualOrInfrequentItemsPercentOfCapacityCut0.097.8-94.40.00.90.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalWarrantIssued

us-gaap:AdjustmentsToAdditionalPaidInCapitalWarrantIssued


Adjustments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-30
Value52470.04057
Percentage of AdjustmentsToAdditionalPaidInCapitalWarrantIssued100.0100.00.0100.0100.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalWarrantIssued us-gaap:ClassOfWarrantOrRight

ual:PayrollSupportProgram2PSP2Warrants


Adjustments
Period End2021-03-31
Value47
Percentage of AdjustmentsToAdditionalPaidInCapitalWarrantIssued100.0

ual:PayrollSupportProgram3PSP3Warrants


Adjustments
Period End2021-06-30
Value43
Percentage of AdjustmentsToAdditionalPaidInCapitalWarrantIssued82.7

us-gaap:AdjustmentsToAdditionalPaidInCapitalWarrantIssued us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


Adjustments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-30
Value52470.04057
Percentage of AdjustmentsToAdditionalPaidInCapitalWarrantIssued100.0100.00.0100.0100.0

us-gaap:AircraftMaintenanceMaterialsAndRepairs

us-gaap:AircraftMaintenanceMaterialsAndRepairs


Aircraft
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value302269199115110434475490421408434455438440479451472454448451448402399424431397415435471458431472480438452469432407414447444439386262245
Percentage of AircraftMaintenanceMaterialsAndRepairs100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AircraftMaintenanceMaterialsAndRepairs dei:LegalEntity

ual:UnitedAirLinesInc


Aircraft
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value302269199115110434475490421408434455438440479451472454448451448402399424431397415435471458431472480438301313282267279299290292251262245
Percentage of AircraftMaintenanceMaterialsAndRepairs100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.066.666.765.365.667.466.965.366.565.0100.0100.0

us-gaap:AircraftRental

us-gaap:AircraftRental


Aircraft
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value52555150475067677381781091191271451451521791591681751781741851942012152222222242302312352402462452512512492552522532568281
Percentage of AircraftRental100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AircraftRental dei:LegalEntity

ual:UnitedAirLinesInc


Aircraft
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value52555150475067677381781091191271451451521791591681751781741851942012152222222242302312352407978787880828081828281
Percentage of AircraftRental100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.032.131.831.131.132.132.231.732.032.0100.0100.0

us-gaap:AirlineCapacityPurchaseArrangements

us-gaap:AirlineCapacityPurchaseArrangements


Airline
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value547479489425388737725721715688638663681619580567549536552572551522565572583570597597591559582621628588583628643616596619615573602417405
Percentage of AirlineCapacityPurchaseArrangements100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AirlineCapacityPurchaseArrangements dei:LegalEntity

ual:UnitedAirLinesInc


Airline
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value547479489425388737725721715688638663681619580567549536552572551522565572583570597597591559582621628588355387386379384407401382400417405
Percentage of AirlineCapacityPurchaseArrangements100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.060.961.660.061.564.465.865.266.766.4100.0100.0

us-gaap:AssetImpairmentCharges

us-gaap:AssetImpairmentCharges


Asset
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-312015-09-302015-06-302015-03-312014-12-312014-06-302014-03-312013-12-312012-12-312012-03-312010-12-312010-09-302010-06-302010-03-31
Value591373880501020.0618.0232111112310.0150.00.00.00.04124818112.016321.033246.053227317
Percentage of AssetImpairmentCharges100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ContractWithCustomerLiabilityRevenueRecognized us-gaap:ProductOrService

us-gaap:ContractWithCustomerLiabilityRevenueRecognized

ual:AdvanceTicketSales


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value150070010050050026000.041003900270010041003500
Percentage of ContractWithCustomerLiabilityRevenueRecognized100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtInstrumentBasisSpreadOnVariableRate1 dei:LegalEntity, us-gaap:CreditFacility, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType, us-gaap:VariableRate

us-gaap:DebtInstrumentBasisSpreadOnVariableRate1

ual:UnitedAirLinesInc, us-gaap:RevolvingCreditFacility, us-gaap:SecuredDebt, us-gaap:SubsequentEvent, ual:AlternativeRate


Debt
Period End2020-07-02
Value0.0125
Percentage of DebtInstrumentBasisSpreadOnVariableRate1100.0

ual:UnitedAirLinesInc, us-gaap:RevolvingCreditFacility, us-gaap:SecuredDebt, us-gaap:SubsequentEvent, us-gaap:LondonInterbankOfferedRateLIBOR


Debt
Period End2020-07-02
Value0.0225
Percentage of DebtInstrumentBasisSpreadOnVariableRate1180.0

us-gaap:DebtInstrumentBasisSpreadOnVariableRate1 us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType, us-gaap:VariableRate

ual:TermLoanFacility, us-gaap:LineOfCredit, us-gaap:SubsequentEvent, us-gaap:LondonInterbankOfferedRateLIBOR


Debt
Period End2020-07-02
Value0.0525
Percentage of DebtInstrumentBasisSpreadOnVariableRate1420.0

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value7.07.09.09.0111110.01215158.08.08.08.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-42.0-43.0-42.0-48.0-37.0-35.0-31.0-29.0-29.0-29.0-33.0-32.0-32.0-33.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses-600.0-614.3-466.7-533.3-336.4-318.2-310.0-241.7-193.3-193.3-412.5-400.0-400.0-412.5

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-31.0-31.0-31.0-31.0-31.0-31.0-31.0-23.0-9.0-10.0-9.0-9.0-10.0-9.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanBenefitObligationPeriodIncreaseDecrease us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanBenefitObligationPeriodIncreaseDecrease

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-09-30
Value-275.0
Percentage of DefinedBenefitPlanBenefitObligationPeriodIncreaseDecrease100.0

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312016-09-302016-06-30
Value1.00.00.01.00.00.00.01.00.01.01.00.00.01.00.01.01.00.01.0
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets100.00.00.0100.00.00.00.0100.00.0100.0100.00.00.0100.00.0100.0100.00.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value717169779191737373727373737361616160545454
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets7100.00.00.00.09100.00.00.00.07300.00.07300.07300.00.00.06100.00.06100.00.05400.00.05400.0

us-gaap:DefinedBenefitPlanInterestCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanInterestCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value7.06.07.07.07.07.08.010.014151516151516161717202222
Percentage of DefinedBenefitPlanInterestCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value464645525656565657575554545455555555495050
Percentage of DefinedBenefitPlanInterestCost657.1766.7642.9742.9800.0800.0700.0560.0407.1380.0366.7337.5360.0360.0343.8343.8323.5323.5245.0227.3227.3

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value-29.016-31.04692-33.0-30.0-23.0-8.0-8.00.01.00.01.02.02.02.01.0-46.0-34.013
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value787811242517257606062607370707176777676434644
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost-269.0487.5-361.3923.9187.0-172.7-200.0-260.9-775.0-750.00.07000.00.07100.03800.03850.03800.07600.0-93.5-135.3338.5

us-gaap:DefinedBenefitPlanOtherCosts us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanOtherCosts

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302020-06-302020-03-31
Value1.0113.0
Percentage of DefinedBenefitPlanOtherCosts100.0100.0100.0

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312020-09-30
Value0.0-1.0
Percentage of DefinedBenefitPlanRecognizedNetGainLossDueToCurtailments0.0100.0

us-gaap:DefinedBenefitPlanServiceCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanServiceCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value3.02.02.03.03.02.03.02.03.02.03.03.03.03.03.04.04.02.05.04.06.0
Percentage of DefinedBenefitPlanServiceCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value606051585354464646465757575749484949282927
Percentage of DefinedBenefitPlanServiceCost2000.03000.02550.01933.31766.72700.01533.32300.01533.32300.01900.01900.01900.01900.01633.31200.01225.02450.0560.0725.0450.0

us-gaap:DepreciationAndAmortization

us-gaap:DepreciationAndAmortization


Depreciation
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value626618615606575560547578564557541539556536518504503491479476469445429431422417409421435425408385379378380390384385388403232223221
Percentage of DepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationAndAmortization dei:LegalEntity

ual:UnitedAirLinesInc


Depreciation
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value626618615606575560547578564557541539556536518504503491479476469445429431422417409421435425408235232232231237228229227227232223
Percentage of DepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.061.061.261.460.860.859.459.558.556.3100.0100.0

us-gaap:EquitySecuritiesFvNiUnrealizedGainLoss us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:EquitySecuritiesFvNiUnrealizedGainLoss

ual:Azul


Equity
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-23.0-447.0179.0-293.0136213814
Percentage of EquitySecuritiesFvNiUnrealizedGainLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinanceLeasePrincipalPayments

us-gaap:FinanceLeasePrincipalPayments


Finance
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value131223184642432022221718
Percentage of FinanceLeasePrincipalPayments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinanceLeasePrincipalPayments dei:LegalEntity

ual:UnitedAirLinesInc


Finance
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value131223184642432022221718
Percentage of FinanceLeasePrincipalPayments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FuelCosts

us-gaap:FuelCosts


Fuel
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value123285167950824017262249229623852023238025722390196518751809166915601555160314371218161819342106186425303127310129172965326230683050309534063408322931053371322726722460153414861207
Percentage of FuelCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FuelCosts dei:LegalEntity

ual:UnitedAirLinesInc


Fuel
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value12328516795082401726224922962385202323802572239019651875180916691560155516031437121816181934210618642530312731012917296532623068305017451914192918421786194918331512147315341486
Percentage of FuelCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.056.456.256.657.057.557.856.856.659.9100.0100.0

us-gaap:ImpairmentOfIntangibleAssetsExcludingGoodwill us-gaap:IndefiniteLivedIntangibleAssetsByMajorClass

us-gaap:ImpairmentOfIntangibleAssetsExcludingGoodwill

us-gaap:UseRights


Impairment
Period End2021-03-312020-12-312020-09-302020-06-30
Value500.00.080
Percentage of ImpairmentOfIntangibleAssetsExcludingGoodwill100.00.00.0100.0

us-gaap:IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance

us-gaap:IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance


Income
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312015-12-312015-09-30
Value7440276466-1466.0-3218.0
Percentage of IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestCostsCapitalizedAdjustment

us-gaap:InterestCostsCapitalizedAdjustment


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value22171716172120222122191814192020212324201414111313121213131414121211119.09.08.08.010.08.0
Percentage of InterestCostsCapitalizedAdjustment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestCostsCapitalizedAdjustment dei:LegalEntity

ual:UnitedAirLinesInc


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-30
Value221717161721202221221918141920202123242014141113131212131314141212115.04.03.08.03.06.03.0
Percentage of InterestCostsCapitalizedAdjustment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.045.544.433.3100.037.560.037.5

us-gaap:InterestCostsIncurred

us-gaap:InterestCostsIncurred


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value426353351345196171161191191188
Percentage of InterestCostsIncurred100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestCostsIncurred dei:LegalEntity

ual:UnitedAirLinesInc


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value426353351345196171161191191188
Percentage of InterestCostsIncurred100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InvestmentIncomeInterest

us-gaap:InvestmentIncomeInterest


Investment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value127.05.08.0112630363829312825171617131111149.08.09.05.06.05.05.08.04.05.05.05.06.05.07.04.07.05.05.06.05.04.07.05.02.01.0
Percentage of InvestmentIncomeInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InvestmentIncomeInterest dei:LegalEntity

ual:UnitedAirLinesInc


Investment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value127.05.08.0112630363829312825171617131111149.08.09.05.06.05.05.08.04.05.05.05.06.05.03.04.02.03.03.02.03.02.03.05.02.0
Percentage of InvestmentIncomeInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.042.9100.028.660.060.033.360.050.042.9100.0100.0

us-gaap:LaborAndRelatedExpense

us-gaap:LaborAndRelatedExpense


Labor
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value227622242168222921702955307830633057287329242930287827262704281228682661256826252592249024242534245423012251234421872153211422092175212719862038202418971910202019161806182211291061990
Percentage of LaborAndRelatedExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LaborAndRelatedExpense dei:LegalEntity

ual:UnitedAirLinesInc


Labor
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value22762224216822292170295530783063305728732924293028782726270428122868266125682625259224902424253424542301225123442187215321142209217521271068104610931027105510921038987103211291061
Percentage of LaborAndRelatedExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.053.851.354.054.155.254.154.254.756.6100.0100.0

us-gaap:LandingFeesAndOtherRentals

us-gaap:LandingFeesAndOtherRentals


Landing
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value564519575500429623650645660588602596603558570585541544553546541525556551553543568567567572546540507497453504503469477476502473511268271
Percentage of LandingFeesAndOtherRentals100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LandingFeesAndOtherRentals dei:LegalEntity

ual:UnitedAirLinesInc


Landing
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value564519575500429623650645660588602596603558570585541544553546541525556551553543568567567572546540507497223271281255255246275252281268271
Percentage of LandingFeesAndOtherRentals100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.049.253.855.954.453.551.754.853.355.0100.0100.0

us-gaap:NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1

us-gaap:NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1


Noncash
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-31
Value2525095171091878612892350.065741711196711271560.0596921177599349107283375-10.01479146181852051360.0333364
Percentage of NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0

us-gaap:NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1 dei:LegalEntity

ual:UnitedAirLinesInc


Noncash
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value2525095171091878612892350.065741711196711271560.0596921177599349107283375-10.0147914618185205136
Percentage of NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OciBeforeReclassificationsBeforeTaxAttributableToParent us-gaap:StatementEquityComponents

us-gaap:OciBeforeReclassificationsBeforeTaxAttributableToParent

us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Oci
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1113-212.0-11.0-721.0-49.0-265.0394-29.05.0
Percentage of OciBeforeReclassificationsBeforeTaxAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Oci
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.0-1.00.017-16.00.00.02.05.0
Percentage of OciBeforeReclassificationsBeforeTaxAttributableToParent0.0-7.7-0.0-2.432.7-0.00.0-6.9100.0

us-gaap:OciBeforeReclassificationsNetOfTaxAttributableToParent

us-gaap:OciBeforeReclassificationsNetOfTaxAttributableToParent


Oci
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value9.09.0-165.0-9.0-548.0-50.0-206.0307-20.07.0
Percentage of OciBeforeReclassificationsNetOfTaxAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLeaseImpairmentLoss us-gaap:PropertyPlantAndEquipmentByType

us-gaap:OperatingLeaseImpairmentLoss

ual:EmbeddedAircraftLease


Operating
Period End2020-09-30
Value38
Percentage of OperatingLeaseImpairmentLoss100.0

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsTax

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2.03.0-48.0-2.0-156.0-15.0-59.087-7.03.0890.00.0-6.062-6.08.010.0
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value-12.0-14.0129-250.050141214-304.017-7.0-288.0-12.0-12.0-30.0194-3.0-4.08.022475-10.024-52.012-28.0-2.01050821821-1095.0-51.0
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax dei:LegalEntity

ual:UnitedAirLinesInc


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value-12.0-14.0129-250.050141214-304.017-7.0-288.0-12.0-12.0-30.0194-3.0-4.08.022475-10.024-52.012-28.0-2.01050821821-1095.0-51.0
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherCostAndExpenseOperating

us-gaap:OtherCostAndExpenseOperating


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value95787482667952814531630159115461508150814671428139814581459140813321423143113281239129612961300118611681240135213831302136213141217121411701174112311601167113911371190685644609
Percentage of OtherCostAndExpenseOperating100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherCostAndExpenseOperating dei:LegalEntity

ual:UnitedAirLinesInc


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value95687482567952714531630159015461507150714671428139714571459140713321421143113281238129612951299118611671245135213751301136213131217990912762726748709698674755679644
Percentage of OtherCostAndExpenseOperating99.9100.099.9100.099.8100.0100.099.9100.099.999.9100.0100.099.999.9100.099.9100.099.9100.0100.099.9100.099.999.9100.099.9100.4100.099.499.9100.099.9100.081.577.964.964.664.560.861.359.363.499.1100.0

us-gaap:OtherSignificantNoncashTransactionValueOfConsiderationReceived1

us-gaap:OtherSignificantNoncashTransactionValueOfConsiderationReceived1


Other
Period End2021-06-302021-03-31
Value5881
Percentage of OtherSignificantNoncashTransactionValueOfConsiderationReceived1100.0100.0

us-gaap:OtherSignificantNoncashTransactionValueOfConsiderationReceived1 dei:LegalEntity

ual:UnitedAirLinesInc


Other
Period End2021-06-302021-03-31
Value5881
Percentage of OtherSignificantNoncashTransactionValueOfConsiderationReceived1100.0100.0

us-gaap:PaymentsForProceedsFromOtherInvestingActivities

us-gaap:PaymentsForProceedsFromOtherInvestingActivities


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312011-03-312010-12-312010-09-302010-06-302010-03-31
Value-1.0-10.00.04.0-13.0-1.0-89.027-5.0-12.0-61.0-87.0-5.0-2.022-19.0-115.0-8.0-18.0-1.07.0-1.04514-18.0-19.0-3.0-26.0-1.0-7.0-36.0-2.00.0-3.00.0-3.0
Percentage of PaymentsForProceedsFromOtherInvestingActivities100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.0100.0

us-gaap:PaymentsForProceedsFromOtherInvestingActivities dei:LegalEntity

ual:UnitedAirLinesInc


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312010-12-312010-09-30
Value-1.0-10.00.04.0-13.0-1.0-89.027-5.0-12.0-61.0-87.0-5.0-2.022-19.0-115.0-8.0-18.0-1.07.0-1.04514-18.0-19.0-3.0-26.0-1.0-7.0-37.0-1.0-3.0
Percentage of PaymentsForProceedsFromOtherInvestingActivities100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0102.80.0100.0

us-gaap:PaymentsOfDebtIssuanceCosts

us-gaap:PaymentsOfDebtIssuanceCosts


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value74246133510.02113176.06.09.016
Percentage of PaymentsOfDebtIssuanceCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsOfDebtIssuanceCosts dei:LegalEntity

ual:UnitedAirLinesInc


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value74246133510.02113176.06.09.016
Percentage of PaymentsOfDebtIssuanceCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireShortTermInvestments

us-gaap:PaymentsToAcquireShortTermInvestments


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.02.09.0541729725719724
Percentage of PaymentsToAcquireShortTermInvestments0.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireShortTermInvestments dei:LegalEntity

ual:UnitedAirLinesInc


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value0.02.09.0541729725719724577649730596657997813774779716635638
Percentage of PaymentsToAcquireShortTermInvestments0.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:PostemploymentBenefitsPeriodExpense

us-gaap:PostemploymentBenefitsPeriodExpense


Postemployment
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-31
Value11417162350630.02.02.06.06.07.09.011141523413710.0136.08.04.02825501416.03814910.00.0140.00.07649
Percentage of PostemploymentBenefitsPeriodExpense100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.00.00.0100.0100.0

us-gaap:ProceedsFromIssuanceOfCommonStock

us-gaap:ProceedsFromIssuanceOfCommonStock


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-04-21
Value0.050010000.01100
Percentage of ProceedsFromIssuanceOfCommonStock0.0100.0100.00.0100.0

us-gaap:ProceedsFromIssuanceOfCommonStock us-gaap:SubsidiarySaleOfStock

ual:A2020ATMOffering


Proceeds
Period End2021-03-31
Value282
Percentage of ProceedsFromIssuanceOfCommonStock56.4

ual:A2021ATMOffering


Proceeds
Period End2021-06-302021-03-31
Value0.0250
Percentage of ProceedsFromIssuanceOfCommonStock0.050.0

ual:EquityDistributionAgreement


Proceeds
Period End2020-12-312020-06-30
Value96722
Percentage of ProceedsFromIssuanceOfCommonStock96.70.0

us-gaap:ProceedsFromIssuanceOfUnsecuredDebt

us-gaap:ProceedsFromIssuanceOfUnsecuredDebt


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-30
Value9477530.015001300
Percentage of ProceedsFromIssuanceOfUnsecuredDebt100.0100.00.0100.0100.0

us-gaap:ProceedsFromIssuanceOfWarrants

us-gaap:ProceedsFromIssuanceOfWarrants


Proceeds
Period End2021-03-312020-12-312020-09-302020-06-30
Value470.09.057
Percentage of ProceedsFromIssuanceOfWarrants100.00.0100.0100.0

us-gaap:ProceedsFromIssuanceOrSaleOfEquity

us-gaap:ProceedsFromIssuanceOrSaleOfEquity


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302009-10-31
Value0.05329680.0132
Percentage of ProceedsFromIssuanceOrSaleOfEquity0.0100.0100.00.0100.0

us-gaap:ProceedsFromIssuanceOrSaleOfEquity dei:LegalEntity

ual:UnitedAirLinesInc


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-30
Value0.05329680.0
Percentage of ProceedsFromIssuanceOrSaleOfEquity0.0100.0100.00.0

us-gaap:ProceedsFromLinesOfCredit dei:LegalEntity, us-gaap:CreditFacility, us-gaap:LongtermDebtType

us-gaap:ProceedsFromLinesOfCredit

ual:UnitedAirLinesInc, us-gaap:RevolvingCreditFacility, us-gaap:SecuredDebt


Proceeds
Period End2020-07-02
Value1000
Percentage of ProceedsFromLinesOfCredit100.0

us-gaap:ProceedsFromLinesOfCredit dei:LegalEntity, us-gaap:CreditFacility, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType, us-gaap:VariableRate

ual:UnitedAirLinesInc, us-gaap:RevolvingCreditFacility, us-gaap:SecuredDebt, us-gaap:SubsequentEvent, us-gaap:LondonInterbankOfferedRateLIBOR


Proceeds
Period End2020-07-02
Value1000
Percentage of ProceedsFromLinesOfCredit100.0

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-09-302010-06-302010-03-31
Value-1.0-21.0-1.0-1.00.0-18.0-1.01.0-1.0-29.030-6.0-9.0-32.064-2.0-10.0-65.042-16.0-22.0-2.015-7.0-6.0-15.038-33.0-59.01271-25.0-12.0-33.0-8.0-2.0-8.014-21.04.00.0327.0-15.0-10.0
Percentage of ProceedsFromPaymentsForOtherFinancingActivities100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities dei:LegalEntity

ual:UnitedAirLinesInc


Proceeds
Period End2020-12-312020-09-302019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-30
Value-1.00.0-1.02.0-1.00.031-6.0-8.0-16.064-1.0-9.0-53.043-16.0-20.02.016-6.0-6.0-6.038-33.0-58.02068-25.0-12.0-30.03.0-2.0-9.03.03.03.0-3.012167.0
Percentage of ProceedsFromPaymentsForOtherFinancingActivities100.0-0.0100.0200.0100.0-0.0103.3100.088.950.0100.050.090.081.5102.4100.090.9-100.0106.785.7100.040.0100.0100.098.3166.795.8100.0100.090.9-37.5100.0112.521.4-14.375.00.037.50.0100.0

us-gaap:ProceedsFromSaleMaturityAndCollectionsOfInvestments

us-gaap:ProceedsFromSaleMaturityAndCollectionsOfInvestments


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value79105137408847927714798716768637524
Percentage of ProceedsFromSaleMaturityAndCollectionsOfInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromSaleMaturityAndCollectionsOfInvestments dei:LegalEntity

ual:UnitedAirLinesInc


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value79105137408847927714798716768637524
Percentage of ProceedsFromSaleMaturityAndCollectionsOfInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProvisionForLoanLossesExpensed

us-gaap:ProvisionForLoanLossesExpensed


Provision
Period End2020-12-312020-09-302020-06-302020-03-312019-06-302019-03-31
Value0.00.00.06970.00.0
Percentage of ProvisionForLoanLossesExpensed0.00.00.0100.00.00.0

us-gaap:ProvisionForLoanLossesExpensed us-gaap:CounterpartyName, us-gaap:FinancingReceivableRecordedInvestmentByClassOfFinancingReceivable

ual:BRWAviationHoldingLLCAndBRWAviationLLCBRW, ual:TermLoanReceivable


Provision
Period End2020-09-302020-06-302020-03-31
Value0.00.0697
Percentage of ProvisionForLoanLossesExpensed0.00.0100.0

us-gaap:ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent us-gaap:StatementEquityComponents

us-gaap:ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent

us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Reclassification
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-5000000.0-5000000.0-45000000.0-333000000.0-77000000.04000000.010000000.04000000.0-8000000.0-4000000.0
Percentage of ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent

us-gaap:ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent


Reclassification
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value-3000000.0-4000000.0-35000000.0-259000000.0-60000000.03000000.08000000.04000000.0-6000000.0-3000000.0
Percentage of ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ReclassificationFromAociCurrentPeriodTax

us-gaap:ReclassificationFromAociCurrentPeriodTax


Reclassification
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-2.0-1.0-190.07417-1.0-2.0-1.02.0-1.0-23.03.04.03.04.05.06.06.0
Percentage of ReclassificationFromAociCurrentPeriodTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RestructuringSettlementAndImpairmentProvisions

us-gaap:RestructuringSettlementAndImpairmentProvisions


Restructuring
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-948.0-1377.0-149.0-1081.0-1449.063130277118301171294031504451-31.0454341901317655641794316952
Percentage of RestructuringSettlementAndImpairmentProvisions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RestructuringSettlementAndImpairmentProvisions dei:LegalEntity

ual:UnitedAirLinesInc


Restructuring
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-948.0-1377.0-149.0-1081.0-1449.063130277118301171294031504451-31.0454341901317655641794316952
Percentage of RestructuringSettlementAndImpairmentProvisions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability

us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability


Right
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value3418013416183015424548511264340.0103
Percentage of RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0

us-gaap:RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability dei:LegalEntity

ual:UnitedAirLinesInc


Right
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value3418013416183015424548511264340.0103
Percentage of RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0

us-gaap:SellingExpense

us-gaap:SellingExpense


Selling
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-302010-03-31
Value13985805331295417432442360396427393342328352362307316345339303316366348312334375346318338377347328314356345337333377375350338204198172
Percentage of SellingExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:SellingExpense dei:LegalEntity

ual:UnitedAirLinesInc


Selling
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312010-09-302010-06-30
Value13985805331295417432442360396427393342328352362307316345339303316366348312334375346318338377347328158172172182168194199187182204198
Percentage of SellingExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.050.348.349.954.050.551.553.153.453.8100.0100.0

us-gaap:StockIssuedDuringPeriodSharesNewIssues us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodSharesNewIssues

us-gaap:CommonStock


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-30
Value0.011200.043
Percentage of StockIssuedDuringPeriodSharesNewIssues0.0100.0100.00.0100.0

us-gaap:StockIssuedDuringPeriodSharesNewIssues us-gaap:SubsidiarySaleOfStock

ual:A2020ATMOffering


Stock
Period End2021-03-31
Value7.0
Percentage of StockIssuedDuringPeriodSharesNewIssues63.6

ual:A2021ATMOffering


Stock
Period End2021-06-302021-03-31
Value0.04.0
Percentage of StockIssuedDuringPeriodSharesNewIssues0.036.4

us-gaap:StockIssuedDuringPeriodSharesShareBasedCompensation us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodSharesShareBasedCompensation

us-gaap:CommonStock


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0800000.0-100000.000500000.0000500000.0200000.000200000.0
Percentage of StockIssuedDuringPeriodSharesShareBasedCompensation0.0100.0100.00.00.0100.00.00.00.0100.0100.00.00.0100.0

us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation

us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302010-12-31
Value0.0-21.0-1.0-1.02.0-19.01.0-1.0-1.0-29.01.0-1.04.0
Percentage of StockIssuedDuringPeriodValueShareBasedCompensation0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueShareBasedCompensation us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value-1.0-54.0-1.0-2.0-1.0-55.01.0-3.0-1.0-54.00.0-2.0
Percentage of StockIssuedDuringPeriodValueShareBasedCompensation0.0257.1100.0200.0-50.0289.5100.0300.0100.0186.20.0200.0

us-gaap:RetainedEarnings


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value-1.0-30.0-1.00.01.0-4.00.01.0-1.0-8.01.0
Percentage of StockIssuedDuringPeriodValueShareBasedCompensation0.0142.9100.0-0.050.021.10.0-100.0100.027.6100.0

us-gaap:TreasuryStock


Stock
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value2.0631.01.02.0400.01.01.0330.01.0
Percentage of StockIssuedDuringPeriodValueShareBasedCompensation0.0-300.0-100.0-100.0100.0-210.50.0-100.0-100.0-113.80.0-100.0

us-gaap:StockholdersEquityOther dei:LegalEntity

us-gaap:StockholdersEquityOther

ual:UnitedAirLinesInc


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-51.0-27.0-965.0-40.0-1199.0181.01.00.0300.02.0-1.018
Percentage of StockholdersEquityOther100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.0100.0100.0100.0

us-gaap:StockholdersEquityOther dei:LegalEntity, us-gaap:StatementEquityComponents

ual:UnitedAirLinesInc, us-gaap:ReceivablesFromStockholder


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-51.0-27.0-965.0-40.0-1199.0181.01.01.0301.01.00.018
Percentage of StockholdersEquityOther100.0100.0100.0100.0100.0100.0100.0100.00.0100.00.050.0-0.0100.0

us-gaap:TangibleAssetImpairmentCharges us-gaap:AircraftType

us-gaap:TangibleAssetImpairmentCharges

srt:B757200


Tangible
Period End2020-12-31
Value94
Percentage of TangibleAssetImpairmentCharges100.0

us-gaap:TreasuryStockSharesAcquired us-gaap:StatementEquityComponents

us-gaap:TreasuryStockSharesAcquired

us-gaap:CommonStock


Treasury
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.00.00.04.42.44.16.66.12.80.56.47.8
Percentage of TreasuryStockSharesAcquired0.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:TreasuryStockValueAcquiredCostMethod

us-gaap:TreasuryStockValueAcquiredCostMethod


Treasury
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.00.00.034221536353652719034407569
Percentage of TreasuryStockValueAcquiredCostMethod0.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:TreasuryStockValueAcquiredCostMethod us-gaap:StatementEquityComponents

us-gaap:TreasuryStock


Treasury
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value0.00.00.034221536353652724034407569
Percentage of TreasuryStockValueAcquiredCostMethod0.00.00.0100.0100.0100.0100.0100.0126.3100.0100.0100.0

us-gaap:UnrealizedGainLossOnDerivatives

us-gaap:UnrealizedGainLossOnDerivatives


Unrealized
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value0.00.00.0-24.018-4.0-4.03.0
Percentage of UnrealizedGainLossOnDerivatives0.00.00.0100.0100.0100.0100.0100.0

us-gaap:UnrealizedGainLossOnInvestments

us-gaap:UnrealizedGainLossOnInvestments


Unrealized
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312017-09-30
Value147-22.0101159.0-319.08121341756290.00.0
Percentage of UnrealizedGainLossOnInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0

us-gaap:UnrealizedGainLossOnInvestments dei:LegalEntity

ual:UnitedAirLinesInc


Unrealized
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value147-22.0101159.0-319.081213417
Percentage of UnrealizedGainLossOnInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:UnusualOrInfrequentItemGainGross

us-gaap:UnusualOrInfrequentItemGainGross


Unusual
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-06-30
Value10791810453149415890.0
Percentage of UnusualOrInfrequentItemGainGross100.0100.0100.0100.0100.00.0

dei:EntityCommonStockSharesOutstanding

dei:EntityCommonStockSharesOutstanding


Entity
Period End2020-07-172020-04-302020-02-182019-10-112019-07-122019-04-122019-02-222018-10-122018-07-132018-04-122018-02-142017-10-122017-07-122017-04-122017-02-132016-10-112016-07-122016-04-112016-02-092015-10-132015-07-142015-04-132015-02-102014-10-152014-07-142014-04-142014-02-142013-10-152013-07-152013-04-152013-02-072012-10-152012-07-15
Value290290247253256263266272272277284296304309314317322336359372377382384369373373371361355333332332332
Percentage of EntityCommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

dei:EntityCommonStockSharesOutstanding dei:LegalEntity

ual:UnitedAirLinesInc


Entity
Period End2020-07-172020-04-302020-02-182019-10-112019-07-122019-04-122019-02-222018-10-122018-07-132018-04-122018-02-142017-10-122017-07-122017-04-122017-02-132016-10-112016-07-122016-04-112016-02-092015-10-132015-07-142015-04-132015-02-102014-10-152014-07-142014-04-142014-02-142013-10-152013-07-152013-04-152013-02-072012-10-152012-07-152012-04-152012-02-162011-10-212011-07-15
Value0.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0010.0002050.0002050.0002050.0002050.0002050.0002050.000205
Percentage of EntityCommonStockSharesOutstanding0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

dei:EntityNumberOfEmployees dei:LegalEntity

dei:EntityNumberOfEmployees

ual:UnitedAirLinesInc


Entity
Period End2021-06-302021-03-312020-12-312020-09-302012-12-31
Value84400.084100.074400.087887.047000.0
Percentage of EntityNumberOfEmployees100.0100.0100.0100.0100.0

ual:CapitalLossCarryforwardsValuationAllowance

ual:CapitalLossCarryforwardsValuationAllowance


Capital
Period End2020-12-31
Value185
Percentage of CapitalLossCarryforwardsValuationAllowance100.0

ual:ClassofWarrantorRightNumberOfSecuritiesCalledbyWarrantsOrRightsIssuableUnderAgreement us-gaap:ClassOfWarrantOrRight

ual:ClassofWarrantorRightNumberOfSecuritiesCalledbyWarrantsOrRightsIssuableUnderAgreement

ual:CreditAgreementWarrantAgreement


Classof
Period End2020-09-28
Value16
Percentage of ClassofWarrantorRightNumberOfSecuritiesCalledbyWarrantsOrRightsIssuableUnderAgreement100.0

ual:PayrollSupportProgram2PSP2Warrants


Classof
Period End2021-03-31
Value1.7
Percentage of ClassofWarrantorRightNumberOfSecuritiesCalledbyWarrantsOrRightsIssuableUnderAgreement0.0

ual:ClassofWarrantorRightNumberOfSecuritiesCalledbyWarrantsOrRightsIssuableUnderAgreement us-gaap:ClassOfWarrantOrRight, us-gaap:SubsequentEventType

ual:PayrollSupportProgram2PSP2Warrants, us-gaap:SubsequentEvent


Classof
Period End2021-01-15
Value1.7
Percentage of ClassofWarrantorRightNumberOfSecuritiesCalledbyWarrantsOrRightsIssuableUnderAgreement0.0

ual:ContractWithCustomerLiabilityAdvanceTicketSales us-gaap:ProductOrService

ual:ContractWithCustomerLiabilityAdvanceTicketSales

ual:ElectronicTravelCertificatesETCsAndFutureFlightCreditsFFCs


Contract
Period End2021-06-302021-03-31
Value26002800
Percentage of ContractWithCustomerLiabilityAdvanceTicketSales100.0100.0

ual:ContractWithCustomerLiabilityCurrentAdvanceTicketSales

ual:ContractWithCustomerLiabilityCurrentAdvanceTicketSales


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value69605502483349074950530948194381
Percentage of ContractWithCustomerLiabilityCurrentAdvanceTicketSales100.0100.0100.0100.0100.0100.0100.0100.0

ual:ContractWithCustomerLiabilityCurrentAdvanceTicketSales dei:LegalEntity

ual:UnitedAirLinesInc


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value69605502483349074950530948194381
Percentage of ContractWithCustomerLiabilityCurrentAdvanceTicketSales100.0100.0100.0100.0100.0100.0100.0100.0

ual:ContractWithCustomerLiabilityCurrentFrequentFlyer

ual:ContractWithCustomerLiabilityCurrentFrequentFlyer


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value20991251908772840135524402286
Percentage of ContractWithCustomerLiabilityCurrentFrequentFlyer100.0100.0100.0100.0100.0100.0100.0100.0

ual:ContractWithCustomerLiabilityCurrentFrequentFlyer dei:LegalEntity

ual:UnitedAirLinesInc


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value20991251908772840135524402286
Percentage of ContractWithCustomerLiabilityCurrentFrequentFlyer100.0100.0100.0100.0100.0100.0100.0100.0

ual:ContractWithCustomerLiabilityNoncurrentFrequentFlyer

ual:ContractWithCustomerLiabilityNoncurrentFrequentFlyer


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value40864858506750634830413328362719
Percentage of ContractWithCustomerLiabilityNoncurrentFrequentFlyer100.0100.0100.0100.0100.0100.0100.0100.0

ual:ContractWithCustomerLiabilityNoncurrentFrequentFlyer dei:LegalEntity

ual:UnitedAirLinesInc


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-31
Value40864858506750634830413328362719
Percentage of ContractWithCustomerLiabilityNoncurrentFrequentFlyer100.0100.0100.0100.0100.0100.0100.0100.0

ual:DebtCovenantRequiredLiquidity us-gaap:DebtInstrument, us-gaap:LongtermDebtType

ual:DebtCovenantRequiredLiquidity

ual:CARESActCreditAgreement, us-gaap:LineOfCredit


Debt
Period End2020-12-31
Value2000
Percentage of DebtCovenantRequiredLiquidity100.0

ual:CreditAgreement, us-gaap:LineOfCredit


Debt
Period End2020-12-31
Value2000
Percentage of DebtCovenantRequiredLiquidity100.0

ual:DebtInstrumentIncreaseInPrincipalAmountAsAPercentOfTreasuryDisbursements us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType

ual:DebtInstrumentIncreaseInPrincipalAmountAsAPercentOfTreasuryDisbursements

ual:PayrollSupportProgram2PSP2Note, us-gaap:UnsecuredDebt, us-gaap:SubsequentEvent


Debt
Period End2021-02-15
Value30.0
Percentage of DebtInstrumentIncreaseInPrincipalAmountAsAPercentOfTreasuryDisbursements100.0

ual:DeferredGrantIncome us-gaap:DebtInstrument

ual:DeferredGrantIncome

ual:PayrollSupportProgram3PSP3Note


Deferred
Period End2021-06-30
Value1100
Percentage of DeferredGrantIncome100.0

ual:DeferredTaxAssetLeasingArrangements

ual:DeferredTaxAssetLeasingArrangements


Deferred
Period End2020-12-312019-12-312018-12-31
Value124712561338
Percentage of DeferredTaxAssetLeasingArrangements100.0100.0100.0

ual:DeferredTaxAssetLeasingArrangements dei:LegalEntity

ual:UnitedAirLinesInc


Deferred
Period End2020-12-312019-12-312018-12-31
Value124712561338
Percentage of DeferredTaxAssetLeasingArrangements100.0100.0100.0

ual:DeferredTaxAssetsSaleLeasebackLiability

ual:DeferredTaxAssetsSaleLeasebackLiability


Deferred
Period End2020-12-31
Value260
Percentage of DeferredTaxAssetsSaleLeasebackLiability100.0

ual:DeferredTaxAssetsSaleLeasebackLiability dei:LegalEntity

ual:UnitedAirLinesInc


Deferred
Period End2020-12-31
Value260
Percentage of DeferredTaxAssetsSaleLeasebackLiability100.0

ual:DefinedBenefitPlanEffectOf50BasisPointDecreaseInDiscountRateOnAccumulatedPostretirementBenefitObligation us-gaap:RetirementPlanType

ual:DefinedBenefitPlanEffectOf50BasisPointDecreaseInDiscountRateOnAccumulatedPostretirementBenefitObligation

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-31
Value4842
Percentage of DefinedBenefitPlanEffectOf50BasisPointDecreaseInDiscountRateOnAccumulatedPostretirementBenefitObligation100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-31
Value800700
Percentage of DefinedBenefitPlanEffectOf50BasisPointDecreaseInDiscountRateOnAccumulatedPostretirementBenefitObligation1666.71666.7

ual:ElectronicTravelCertificatesAndFutureFlightCreditsPercentOfCreditsWithExpirationDatesBeyond12Months

ual:ElectronicTravelCertificatesAndFutureFlightCreditsPercentOfCreditsWithExpirationDatesBeyond12Months


Electronic
Period End2020-12-312020-09-30
Value74.090.0
Percentage of ElectronicTravelCertificatesAndFutureFlightCreditsPercentOfCreditsWithExpirationDatesBeyond12Months100.0100.0

ual:EquitySecuritiesOwnershipPercentage us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

ual:EquitySecuritiesOwnershipPercentage

ual:Azul


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-06-302018-12-312018-04-30
Value2.02.02.02.00.020.020.020.020.020.02
Percentage of EquitySecuritiesOwnershipPercentage100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:EquitySecuritiesOwnershipPercentage us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:FinancialInstrument

ual:Azul, us-gaap:PreferredStock


Equity
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-06-30
Value8.08.08.08.00.080.080.080.08
Percentage of EquitySecuritiesOwnershipPercentage400.0400.0400.0400.0400.0400.0400.0400.0

ual:EquitySecuritiesWithoutReadilyDeterminableFairValueOwnershipInterest us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

ual:EquitySecuritiesWithoutReadilyDeterminableFairValueOwnershipInterest

ual:CLEAR


Equity
Period End2020-12-31
Value1.0
Percentage of EquitySecuritiesWithoutReadilyDeterminableFairValueOwnershipInterest100.0

ual:FulcrumBioEnergyInc


Equity
Period End2021-06-30
Value6.0
Percentage of EquitySecuritiesWithoutReadilyDeterminableFairValueOwnershipInterest0.0

ual:FulcrumBioEnergyInc.


Equity
Period End2020-12-312019-12-31
Value6.00.07
Percentage of EquitySecuritiesWithoutReadilyDeterminableFairValueOwnershipInterest600.00.0

ual:EquitySecuritiesWithoutReadilyDeterminableFairValueOwnershipInterest us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:FinancialInstrument

ual:FulcrumBioEnergyInc, us-gaap:PreferredStock


Equity
Period End2021-06-30
Value7.0
Percentage of EquitySecuritiesWithoutReadilyDeterminableFairValueOwnershipInterest0.0

ual:FulcrumBioEnergyInc., us-gaap:PreferredStock


Equity
Period End2020-12-312019-12-31
Value7.00.08
Percentage of EquitySecuritiesWithoutReadilyDeterminableFairValueOwnershipInterest700.00.0

ual:ExciseTaxRefundsReceivable

ual:ExciseTaxRefundsReceivable


Excise
Period End2020-12-31
Value150
Percentage of ExciseTaxRefundsReceivable100.0

ual:FinancialLiabilitiesSaleLeasebackTransactionsNoncurrent

ual:FinancialLiabilitiesSaleLeasebackTransactionsNoncurrent


Financial
Period End2021-06-302021-03-312020-12-312020-09-30
Value168315681140957
Percentage of FinancialLiabilitiesSaleLeasebackTransactionsNoncurrent100.0100.0100.0100.0

ual:FinancialLiabilitiesSaleLeasebackTransactionsNoncurrent dei:LegalEntity

ual:UnitedAirLinesInc


Financial
Period End2021-06-302021-03-312020-12-312020-09-30
Value168315681140957
Percentage of FinancialLiabilitiesSaleLeasebackTransactionsNoncurrent100.0100.0100.0100.0

ual:GovernmentAssistanceDeferredCreditCurrent

ual:GovernmentAssistanceDeferredCreditCurrent


Government
Period End2021-06-302020-09-302020-06-302019-12-31
Value113245315080.0
Percentage of GovernmentAssistanceDeferredCreditCurrent100.0100.0100.00.0

ual:GovernmentAssistanceDeferredCreditCurrent dei:LegalEntity

ual:UnitedAirLinesInc


Government
Period End2021-06-302020-06-302019-12-31
Value113215080.0
Percentage of GovernmentAssistanceDeferredCreditCurrent100.0100.00.0

ual:LesseeOperatingAndFinanceLeaseNotYetCommencedAmount

ual:LesseeOperatingAndFinanceLeaseNotYetCommencedAmount


Lessee
Period End2020-12-31
Value740
Percentage of LesseeOperatingAndFinanceLeaseNotYetCommencedAmount100.0

ual:LongTermDebtMaturityAfterYearFour dei:LegalEntity

ual:LongTermDebtMaturityAfterYearFour

ual:UalAndUnited


Long
Period End2021-06-302021-03-312020-09-30
Value206831089612150
Percentage of LongTermDebtMaturityAfterYearFour100.0100.0100.0

ual:NumberOfAircraftInSaleLeasebackTransactionIncludedInFlightEquipment

ual:NumberOfAircraftInSaleLeasebackTransactionIncludedInFlightEquipment


Number
Period End2020-12-31
Value11.0
Percentage of NumberOfAircraftInSaleLeasebackTransactionIncludedInFlightEquipment100.0

ual:OperatingLossCarryforwardsAndTaxCreditCarryforwardsValuationAllowance us-gaap:IncomeTaxAuthority

ual:OperatingLossCarryforwardsAndTaxCreditCarryforwardsValuationAllowance

us-gaap:StateAndLocalJurisdiction


Operating
Period End2020-12-31
Value62
Percentage of OperatingLossCarryforwardsAndTaxCreditCarryforwardsValuationAllowance100.0

ual:OperatingLossCarryforwardsTaxEffectedAmount dei:LegalEntity, us-gaap:IncomeTaxAuthority

ual:OperatingLossCarryforwardsTaxEffectedAmount

ual:UnitedAirLinesInc, us-gaap:DomesticCountry


Operating
Period End2020-12-31
Value2300
Percentage of OperatingLossCarryforwardsTaxEffectedAmount100.0

ual:UnitedAirLinesInc, us-gaap:StateAndLocalJurisdiction


Operating
Period End2020-12-31
Value200
Percentage of OperatingLossCarryforwardsTaxEffectedAmount8.7

ual:OtherLiabilitiesAndDeferredCreditsNoncurrent

ual:OtherLiabilitiesAndDeferredCreditsNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302018-12-31
Value106081121510817108771024289237831718075787428
Percentage of OtherLiabilitiesAndDeferredCreditsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

ual:OtherLiabilitiesAndDeferredCreditsNoncurrent dei:LegalEntity

ual:UnitedAirLinesInc


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302018-12-31
Value106081121510817109041027089517859720776067455
Percentage of OtherLiabilitiesAndDeferredCreditsNoncurrent100.0100.0100.0100.2100.3100.3100.4100.4100.4100.4

ual:PayrollSupportProgramFundingProvided

ual:PayrollSupportProgramFundingProvided


Payroll
Period End2020-09-302020-06-302020-04-20
Value510050005000
Percentage of PayrollSupportProgramFundingProvided100.0100.0100.0

ual:PayrollSupportProgramFundingProvided ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms

ual:AmericanRescuePlanActOf2021PSP3


Payroll
Period End2021-04-29
Value2800
Percentage of PayrollSupportProgramFundingProvided0.0

ual:PayrollSupportProgramExtensionAgreementPSP2


Payroll
Period End2021-01-15
Value2600
Percentage of PayrollSupportProgramFundingProvided0.0

ual:PayrollSupportProgramFundingProvided us-gaap:SubsequentEventType

us-gaap:SubsequentEvent


Payroll
Period End2021-01-152020-04-20
Value26005000
Percentage of PayrollSupportProgramFundingProvided0.0100.0

ual:PayrollSupportProgramFundingProvidedAmountsExpectedToBeReceived us-gaap:StatementScenario, ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms

ual:PayrollSupportProgramFundingProvidedAmountsExpectedToBeReceived

srt:ScenarioForecast, ual:AmericanRescuePlanActOf2021PSP3


Payroll
Period End2021-04-22
Value2800
Percentage of PayrollSupportProgramFundingProvidedAmountsExpectedToBeReceived100.0

srt:ScenarioForecast, ual:PayrollSupportProgramExtensionAgreementPSP2


Payroll
Period End2021-04-22
Value391
Percentage of PayrollSupportProgramFundingProvidedAmountsExpectedToBeReceived14.0

ual:PayrollSupportProgramFundingProvidedAmountsExpectedToBeReceivedThroughLoans us-gaap:StatementScenario, ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms, us-gaap:DebtInstrument

ual:PayrollSupportProgramFundingProvidedAmountsExpectedToBeReceivedThroughLoans

srt:ScenarioForecast, ual:AmericanRescuePlanActOf2021PSP3, ual:PayrollSupportProgram3PSP3Note


Payroll
Period End2021-04-22
Value800
Percentage of PayrollSupportProgramFundingProvidedAmountsExpectedToBeReceivedThroughLoans100.0

ual:PayrollSupportProgramFundingProvidedAmountsExpectedToBeReceivedThroughLoans us-gaap:StatementScenario, ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms, us-gaap:DebtInstrument, us-gaap:LongtermDebtType

srt:ScenarioForecast, ual:PayrollSupportProgramExtensionAgreementPSP2, ual:PayrollSupportProgram2PSP2Note, us-gaap:UnsecuredDebt


Payroll
Period End2021-04-22
Value117
Percentage of PayrollSupportProgramFundingProvidedAmountsExpectedToBeReceivedThroughLoans14.6

ual:PayrollSupportProgramFundingProvidedAmountsReceivedThroughDirectGrants ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms

ual:PayrollSupportProgramFundingProvidedAmountsReceivedThroughDirectGrants

ual:AmericanRescuePlanActOf2021PSP3


Payroll
Period End2021-04-29
Value2000
Percentage of PayrollSupportProgramFundingProvidedAmountsReceivedThroughDirectGrants100.0

ual:PayrollSupportProgramExtensionAgreementPSP2


Payroll
Period End2021-01-15
Value1900
Percentage of PayrollSupportProgramFundingProvidedAmountsReceivedThroughDirectGrants0.0

ual:PayrollSupportProgramFundingProvidedAmountsReceivedThroughDirectGrants us-gaap:SubsequentEventType

us-gaap:SubsequentEvent


Payroll
Period End2021-01-15
Value1900
Percentage of PayrollSupportProgramFundingProvidedAmountsReceivedThroughDirectGrants0.0

ual:PayrollSupportProgramFundingProvidedAmountsReceivedThroughLoans ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms, us-gaap:DebtInstrument, us-gaap:LongtermDebtType

ual:PayrollSupportProgramFundingProvidedAmountsReceivedThroughLoans

ual:AmericanRescuePlanActOf2021PSP3, ual:PayrollSupportProgram3PSP3Note, us-gaap:UnsecuredDebt


Payroll
Period End2021-04-29
Value810
Percentage of PayrollSupportProgramFundingProvidedAmountsReceivedThroughLoans100.0

ual:PayrollSupportProgramExtensionAgreementPSP2, ual:PayrollSupportProgram2PSP2Note, us-gaap:UnsecuredDebt


Payroll
Period End2021-01-15
Value753
Percentage of PayrollSupportProgramFundingProvidedAmountsReceivedThroughLoans0.0

ual:PayrollSupportProgramFundingProvidedAmountsReceivedThroughLoans us-gaap:DebtInstrument, us-gaap:LongtermDebtType, us-gaap:SubsequentEventType

ual:PayrollSupportProgram2PSP2Note, us-gaap:UnsecuredDebt, us-gaap:SubsequentEvent


Payroll
Period End2021-02-15
Value753
Percentage of PayrollSupportProgramFundingProvidedAmountsReceivedThroughLoans0.0

ual:RestrictedCashAmountsToBeUsedForBorrowingFeesPrincipalAndInterest

ual:RestrictedCashAmountsToBeUsedForBorrowingFeesPrincipalAndInterest


Restricted
Period End2020-12-31
Value6800
Percentage of RestrictedCashAmountsToBeUsedForBorrowingFeesPrincipalAndInterest100.0

ual:RestrictedCashCurrentFairValueDisclosure us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

ual:RestrictedCashCurrentFairValueDisclosure

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring


Restricted
Period End2021-06-302021-03-312020-12-312020-09-30
Value25425425576
Percentage of RestrictedCashCurrentFairValueDisclosure100.0100.0100.0100.0

ual:RestrictedCashCurrentFairValueDisclosure us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring


Restricted
Period End2021-06-302021-03-312020-12-312020-09-30
Value25425425576
Percentage of RestrictedCashCurrentFairValueDisclosure100.0100.0100.0100.0

ual:RestrictedCashNoncurrentFairValueDisclosure us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

ual:RestrictedCashNoncurrentFairValueDisclosure

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring


Restricted
Period End2021-06-302021-03-312020-12-312020-09-302019-12-31
Value216218218172106
Percentage of RestrictedCashNoncurrentFairValueDisclosure100.0100.0100.0100.0100.0

ual:RestrictedCashNoncurrentFairValueDisclosure us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring


Restricted
Period End2021-06-302021-03-312020-12-312020-09-302019-12-31
Value216218218172106
Percentage of RestrictedCashNoncurrentFairValueDisclosure100.0100.0100.0100.0100.0

ual:UnrecordedUnconditionalPurchaseObligationToBePaidAfterYearFour us-gaap:UnrecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

ual:UnrecordedUnconditionalPurchaseObligationToBePaidAfterYearFour

us-gaap:AirlineCapacityPurchaseArrangements


Unrecorded
Period End2021-06-302021-03-312020-09-302020-06-30
Value3700370033004500
Percentage of UnrecordedUnconditionalPurchaseObligationToBePaidAfterYearFour100.0100.0100.0100.0

us-gaap:CapitalAdditions


Unrecorded
Period End2021-06-302021-03-312020-09-302020-06-30
Value12400102001390013900
Percentage of UnrecordedUnconditionalPurchaseObligationToBePaidAfterYearFour335.1275.7421.2308.9

us-gaap:AccountsPayableRelatedPartiesCurrent dei:LegalEntity, us-gaap:ProductOrService, us-gaap:RecordedUnconditionalPurchaseObligationByCategoryOfItemPurchased

us-gaap:AccountsPayableRelatedPartiesCurrent

ual:UnitedAirLinesInc, us-gaap:RegionalCarrier, ual:CapacityPurchaseAgreements


Accounts
Period End2020-12-312019-12-312018-12-31
Value686953
Percentage of AccountsPayableRelatedPartiesCurrent100.0100.0100.0

us-gaap:AirlineRelatedInventoryNet

us-gaap:AirlineRelatedInventoryNet


Airline
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value9129189329619551070107210659969729851011942924924937882900873842798759738704656631666700685641667646555690695675611645615628508466
Percentage of AirlineRelatedInventoryNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AirlineRelatedInventoryNet dei:LegalEntity

ual:UnitedAirLinesInc


Airline
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value9129189329619551070107210659969729851011942924924937882900873842798759738704656631666700685641667646555690402379327335340347243321
Percentage of AirlineRelatedInventoryNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.057.856.153.551.955.355.347.868.9

us-gaap:AirlineRelatedInventoryValuationReserves

us-gaap:AirlineRelatedInventoryValuationReserves


Airline
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value5185024784834644464254033874214123963803653543423293142952632612492352261871781691611811701621571451361251111039689817464
Percentage of AirlineRelatedInventoryValuationReserves100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AirlineRelatedInventoryValuationReserves dei:LegalEntity

ual:UnitedAirLinesInc


Airline
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value5185024254834644464254033874214123963803653543423293142952632612492352261871781691611811701621571451368681787573696761
Percentage of AirlineRelatedInventoryValuationReserves100.0100.088.9100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.068.873.075.778.182.085.290.595.3

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent


Allowance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302011-03-312010-12-312009-12-31
Value7174789.011309.0119.08.08.06.07.07.07.0111110.010.01212111818222322241517131621201312128.07.07.06.06.06.014
Percentage of AllowanceForDoubtfulAccountsReceivableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent dei:LegalEntity

ual:UnitedAirLinesInc


Allowance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312012-09-302012-06-302012-03-312011-12-312011-09-302011-06-302010-12-31
Value71749.09.011309.0119.08.08.06.07.07.07.0111110.010.01212111818222322241517131621201110.010.05.05.06.05.05.0
Percentage of AllowanceForDoubtfulAccountsReceivableCurrent100.0100.011.5100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.084.683.383.362.571.485.783.383.3

us-gaap:AociBeforeTaxAttributableToParent us-gaap:StatementEquityComponents

us-gaap:AociBeforeTaxAttributableToParent

us-gaap:AccumulatedDefinedBenefitPlansAdjustment


Aoci
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value-1068000000.0-1084000000.0-1102000000.0-935000000.0-1257000000.0-613000000.0-560000000.0-285000000.0-675000000.0-654000000.0-663000000.0-1033000000.0-1048000000.0-1063000000.0-1102000000.0-855000000.0-860000000.0-867000000.0-854000000.0-503000000.0-385000000.0-401000000.0-363000000.0-472000000.0
Percentage of AociBeforeTaxAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


Aoci
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value1000000.01000000.02000000.03000000.03000000.0-14000000.02000000.02000000.03000000.01000000.0-4000000.0-1000000.0-2000000.0-3000000.0-6000000.01000000.03000000.0
Percentage of AociBeforeTaxAttributableToParent-0.1-0.1-0.2-0.3-0.22.3-0.4-0.7-0.4-0.20.60.10.20.30.5-0.1-0.8

us-gaap:AociTaxAttributableToParent

us-gaap:AociTaxAttributableToParent


Aoci
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-312014-12-31
Value474339775.0144160221135140136-55.0-52.0-48.0-39.021323026-256.0-116.0
Percentage of AociTaxAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CapitalizedComputerSoftwareGross

us-gaap:CapitalizedComputerSoftwareGross


Capitalized
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value548422359345356279281290302
Percentage of CapitalizedComputerSoftwareGross100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashAndCashEquivalentsFairValueDisclosure us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:CashAndCashEquivalentsFairValueDisclosure

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value20838126661126913150650534422762295932211848169426212884240414821870237121642179263024831795300634272796335220023117342430093220
Percentage of CashAndCashEquivalentsFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashAndCashEquivalentsFairValueDisclosure us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value20838126661126913150650534422762295932211848169426212884240414821870237121642179263024831795300634272796335220023117342430093220
Percentage of CashAndCashEquivalentsFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashCollateralForBorrowedSecurities

us-gaap:CashCollateralForBorrowedSecurities


Cash
Period End2020-12-31
Value217
Percentage of CashCollateralForBorrowedSecurities100.0

us-gaap:ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 us-gaap:ClassOfWarrantOrRight

us-gaap:ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1

ual:CreditAgreementWarrantAgreement


Class
Period End2020-09-28
Value31.5
Percentage of ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1100.0

ual:PayrollSupportProgram3PSP3Warrants


Class
Period End2021-06-30
Value53.92
Percentage of ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights10.0

us-gaap:ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 us-gaap:ClassOfWarrantOrRight, us-gaap:SubsequentEventType

ual:PayrollSupportProgram2PSP2Warrants, us-gaap:SubsequentEvent


Class
Period End2021-01-15
Value43.26
Percentage of ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights10.0

us-gaap:ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 us-gaap:StatementScenario, ual:UnusualOrInfrequentEventsGovernmentAssistancePrograms

srt:ScenarioForecast, ual:AmericanRescuePlanActOf2021PSP3


Class
Period End2021-04-22
Value53.92
Percentage of ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights10.0

us-gaap:ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights us-gaap:ClassOfWarrantOrRight

us-gaap:ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights

ual:ArcherWarrants


Class
Period End2021-06-30
Value4700000.0
Percentage of ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights100.0

ual:BoomWarrants


Class
Period End2021-06-30
Value568860.0
Percentage of ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights12.1

ual:ClassAClearWarrants


Class
Period End2021-06-30
Value2400000.0
Percentage of ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights51.1

ual:CreditAgreementWarrantAgreement


Class
Period End2020-09-28
Value1700000.0
Percentage of ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights0.0

ual:PayrollSupportProgramPSPWarrants


Class
Period End2020-12-312020-09-302020-04-20
Value4800000.04800000.02300000.0
Percentage of ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights0.00.00.0

us-gaap:ClassOfWarrantOrRightOutstanding

us-gaap:ClassOfWarrantOrRightOutstanding


Class
Period End2021-06-302021-03-31
Value10000000.08200000.0
Percentage of ClassOfWarrantOrRightOutstanding100.0100.0

us-gaap:ClassOfWarrantOrRightOutstanding us-gaap:ClassOfWarrantOrRight

ual:PayrollSupportProgram2PSP2Warrants


Class
Period End2021-06-302021-03-31
Value2000000.01700000.0
Percentage of ClassOfWarrantOrRightOutstanding20.020.7

ual:PayrollSupportProgram3PSP3Warrants


Class
Period End2021-06-30
Value1500000.0
Percentage of ClassOfWarrantOrRightOutstanding15.0

us-gaap:CommonStockCapitalSharesReservedForFutureIssuance

us-gaap:CommonStockCapitalSharesReservedForFutureIssuance


Common
Period End2020-12-31
Value6000000.0
Percentage of CommonStockCapitalSharesReservedForFutureIssuance100.0

us-gaap:ContractWithCustomerLiability us-gaap:ProductOrService

us-gaap:ContractWithCustomerLiability

ual:FrequentFlyerProgram


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value618561095975583556705488527652195198513850054987498949374783
Percentage of ContractWithCustomerLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ContractualObligation

us-gaap:ContractualObligation


Contractual
Period End2020-12-312019-12-312019-09-302019-06-302018-12-312017-12-312017-09-302017-06-302017-03-31
Value111001570012300125001130011500120001090010700
Percentage of ContractualObligation100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ContractualObligation us-gaap:DebtInstrument

ual:LoansAndLeasesFromNonUSEntities


Contractual
Period End2021-06-302021-03-312020-12-312020-09-302019-12-312019-09-302019-06-302018-12-312017-12-312017-09-302017-06-302017-03-31
Value10200819983001080032003100320032003300320031003000
Percentage of ContractualObligation0.00.074.80.020.425.225.628.328.726.728.428.0

us-gaap:ContractualObligationDueAfterFifthYear

us-gaap:ContractualObligationDueAfterFifthYear


Contractual
Period End2020-12-31
Value3100
Percentage of ContractualObligationDueAfterFifthYear100.0

us-gaap:ContractualObligationDueInFifthYear

us-gaap:ContractualObligationDueInFifthYear


Contractual
Period End2020-12-31
Value1200
Percentage of ContractualObligationDueInFifthYear100.0

us-gaap:ContractualObligationDueInFourthYear

us-gaap:ContractualObligationDueInFourthYear


Contractual
Period End2020-12-31
Value1500
Percentage of ContractualObligationDueInFourthYear100.0

us-gaap:ContractualObligationDueInNextTwelveMonths

us-gaap:ContractualObligationDueInNextTwelveMonths


Contractual
Period End2020-12-31
Value1800
Percentage of ContractualObligationDueInNextTwelveMonths100.0

us-gaap:ContractualObligationDueInSecondYear

us-gaap:ContractualObligationDueInSecondYear


Contractual
Period End2020-12-31
Value1800
Percentage of ContractualObligationDueInSecondYear100.0

us-gaap:ContractualObligationDueInThirdYear

us-gaap:ContractualObligationDueInThirdYear


Contractual
Period End2020-12-31
Value1700
Percentage of ContractualObligationDueInThirdYear100.0

us-gaap:DebtInstrumentCarryingAmount

us-gaap:DebtInstrumentCarryingAmount


Debt
Period End2020-12-312019-12-312018-12-312014-12-31
Value273011473313636248