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Long-term Debt (Details) (USD $) | 12 Months Ended | 1 Months Ended | 12 Months Ended | 0 Months Ended | 3 Months Ended | 0 Months Ended |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 31, 2014 Loans Mortgages | Oct. 31, 2009 | Dec. 31, 2013 | Apr. 29, 2009 | May 06, 2008 | Dec. 31, 2004 Agreements Mortgages | Feb. 28, 1997 | Jul. 01, 2009 Mortgages | Oct. 03, 2007 Mortgages | Dec. 31, 2006 | Feb. 28, 2005 | Sep. 30, 2004 | Jun. 30, 2014
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Letters of Credit Outstanding Amount | 440,000,000 us-gaap_LettersOfCreditOutstandingAmount |  |  |  |  |  |  |  |  |  |  |  |
Net book value of assets pledged as collateral for the Company's secured borrowings, primarily aircraft and engines | 2,000,000,000 us-gaap_PledgedAssetsSeparatelyReportedSecuritiesPledgedAsCollateralAtFairValue |  |  |  |  |  |  |  |  |  |  |  |
Maximum additional number of assets pledged as collateral in case obligations related to fuel derivatives exceed certain thresholds | 81 luv_MaximumAdditionalNumberOfAssetsPledgedAsCollateralInCaseObligationsRelatedToFuelDerivativesExceedCertainThresholds |  |  |  |  |  |  |  |  |  |  |  |
Net book value of additional assets pledged as collateral in case obligations related to fuel derivatives exceed certain thresholds | 2,000,000,000 luv_NetBookValueOfAdditionalAssetsPledgedAsCollateralInCaseObligationsRelatedToFuelDerivativesExceedCertainThresholds |  |  |  |  |  |  |  |  |  |  |  |
Long-term Debt, by Maturity [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
2015 | 182,000,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsRepaymentsOfPrincipalInNextTwelveMonths |  |  |  |  |  |  |  |  |  |  |  |
2016 | 610,000,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearTwo |  |  |  |  |  |  |  |  |  |  |  |
2017 | 520,000,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearThree |  |  |  |  |  |  |  |  |  |  |  |
2018 | 264,000,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearFour |  |  |  |  |  |  |  |  |  |  |  |
2019 | 514,000,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearFive |  |  |  |  |  |  |  |  |  |  |  |
Thereafter | 551,000,000 us-gaap_LongTermDebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalAfterYearFive |  |  |  |  |  |  |  |  |  |  |  |
AirTran Airways |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft | 22 luv_NumberOfMortgagesOnSecuredAircraft / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |  |  |
AirTran Airways | Interest rate derivatives |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount | 243,000,000 invest_DerivativeNotionalAmount / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateSwapMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |  |  |
AirTran Airways | Maximum | Interest rate derivatives |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) | 6.435%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateSwapMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |  |  |  |  |
Floating-rate 737 Aircraft Notes payable through 2020 | AirTran Airways |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft | 19 luv_NumberOfMortgagesOnSecuredAircraft / us-gaap_DebtInstrumentAxis = luv_NotesPayableAircraftFloatingRateThrough2020Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |  |  |
Number of loans prepaid during period | 8 luv_DebtInstrumentNumberofLoansPrepaidDuringPeriod / us-gaap_DebtInstrumentAxis = luv_NotesPayableAircraftFloatingRateThrough2020Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |  |  |
Weighted average interest rate | 1.66%us-gaap_DebtWeightedAverageInterestRate / us-gaap_DebtInstrumentAxis = luv_NotesPayableAircraftFloatingRateThrough2020Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |  |  |
Fixed-rate 737 Aircraft Notes payable through 2018 - 7.02% | AirTran Airways |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Weighted average interest rate | 7.02%us-gaap_DebtWeightedAverageInterestRate / us-gaap_DebtInstrumentAxis = luv_NotesPayableAircraftFixedRateThrough2018Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |  |  |
5.25% Convertible Senior Notes due 2016 |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Conversion ratio |  | 53.7747 luv_DebtInstrumentConvertibleSharesConversionRatio / us-gaap_DebtInstrumentAxis = luv_ConvertibleDebtDue2016Member |  |  |  |  |  |  |  |  |  |  |
Conversion price |  | $ 615.16 us-gaap_DebtInstrumentConvertibleConversionPrice1 / us-gaap_DebtInstrumentAxis = luv_ConvertibleDebtDue2016Member |  |  |  |  |  |  |  |  |  |  |
5.25% Convertible Senior Notes due 2016 | AirTran Airways |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  | 115,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_ConvertibleDebtDue2016Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  | 5.25%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = luv_ConvertibleDebtDue2016Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |  |
Conversion ratio |  | 167.5224 luv_DebtInstrumentConvertibleSharesConversionRatio / us-gaap_DebtInstrumentAxis = luv_ConvertibleDebtDue2016Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |  |
Extinguishment of debt amount | 5,000,000 us-gaap_ExtinguishmentOfDebtAmount / us-gaap_DebtInstrumentAxis = luv_ConvertibleDebtDue2016Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |  |  |
Repurchase price percentage | 100.00%luv_RepurchasePricePercentage / us-gaap_DebtInstrumentAxis = luv_ConvertibleDebtDue2016Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |  |  |
Conversion option, amount |  |  | 35,000,000 us-gaap_EmbeddedDerivativeNoLongerBifurcatedAmountReclassifiedToStockholdersEquity / us-gaap_DebtInstrumentAxis = luv_ConvertibleDebtDue2016Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |
Unamortized premium |  |  | 10,000,000 us-gaap_DebtInstrumentUnamortizedPremium / us-gaap_DebtInstrumentAxis = luv_ConvertibleDebtDue2016Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  |  |  |  |  |  |  |  |  |
5.25% Convertible Senior Notes due 2016 | Southwest Airlines |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Cash set aside for conversion | 68,000,000 luv_CashSetAsideForConversion / us-gaap_DebtInstrumentAxis = luv_ConvertibleDebtDue2016Member / dei_LegalEntityAxis = us-gaap_ParentCompanyMember |  |  |  |  |  |  |  |  |  |  |  |
2.75% Unsecured Senior Notes Due 2019 |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt | 300,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_UnsecuredSeniorNotesDue2019MemberMember |  |  |  |  |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) | 2.75%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = luv_UnsecuredSeniorNotesDue2019MemberMember |  |  |  |  |  |  |  |  |  |  |  |
Term Loan Agreement due 2019 - 6.84% |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft |  |  |  |  |  |  |  | 5 luv_NumberOfMortgagesOnSecuredAircraft / us-gaap_DebtInstrumentAxis = luv_TermLoanAgreementDue07012019Member |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  | 6.84%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = luv_TermLoanAgreementDue07012019Member |  |  |  |  |
Term Loan Agreement due 2019 - 6.84% | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  | 124,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_TermLoanAgreementDue07012019Member / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |
Term Loan Agreement due 2019 - 6.315% |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft |  |  |  | 14 luv_NumberOfMortgagesOnSecuredAircraft / us-gaap_DebtInstrumentAxis = luv_TermLoanAgreementDue05062019Member |  |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  | 6.315%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = luv_TermLoanAgreementDue05062019Member |  |  |  |  |  |  |  |  |
Term Loan Agreement due 2019 - 6.315% | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Spread on variable rate |  |  |  | 3.30%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = luv_TermLoanAgreementDue05062019Member / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |  |  |  |  |
Term Loan Agreement due 2019 - 6.315% | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  | 332,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_TermLoanAgreementDue05062019Member / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |  |
Term Loan Agreement due 2020 - 5.223% |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft |  |  |  |  | 21 luv_NumberOfMortgagesOnSecuredAircraft / us-gaap_DebtInstrumentAxis = luv_TermLoanAgreementDue2020Member |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  | 600,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_TermLoanAgreementDue2020Member |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  | 5.223%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = luv_TermLoanAgreementDue2020Member |  |  |  |  |  |  |  |
Term Loan Agreement due 2020 - 5.223% | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Spread on variable rate |  |  |  |  | 0.95%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = luv_TermLoanAgreementDue2020Member / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |  |  |  |
Pass Through Certificates due 2022 - 6.24% |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft |  |  |  |  |  |  |  |  | 16 luv_NumberOfMortgagesOnSecuredAircraft / us-gaap_DebtInstrumentAxis = luv_TotalPassThroughCertificatesMember |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  | 500,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_TotalPassThroughCertificatesMember |  |  |  |
Pass Through Certificates due 2022 - 6.24% | Interest rate derivatives | Cash Flow Hedging |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount |  |  |  |  |  |  |  |  | 20,000,000 invest_DerivativeNotionalAmount / us-gaap_DebtInstrumentAxis = luv_TotalPassThroughCertificatesMember / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_InterestRateSwapMember / us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis = us-gaap_CashFlowHedgingMember |  |  |  |
Pass Through Certificates Series A |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  | 412,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_PassThroughCertificatesSeriesAlphaMember |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  | 6.15%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = luv_PassThroughCertificatesSeriesAlphaMember |  |  |  |
Pass Through Certificates Series B |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  | 88,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_PassThroughCertificatesSeriesBMember |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  | 6.65%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = luv_PassThroughCertificatesSeriesBMember |  |  |  |
5.75% Notes due 2016 |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  | 300,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_UnsecuredSeniorNotesDue2016Member |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  |  | 5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = luv_UnsecuredSeniorNotesDue2016Member |  |  |
5.125% Notes due 2017 |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  |  | 300,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_UnsecuredSeniorNotesDue2017Member |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  |  |  | 5.125%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = luv_UnsecuredSeniorNotesDue2017Member |  |
French Credit Agreements due 2018 - 1.06% |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft |  |  |  |  |  | 4 luv_NumberOfMortgagesOnSecuredAircraft / us-gaap_DebtInstrumentAxis = luv_CreditAgreementsDue2018Member |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  | 112,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_CreditAgreementsDue2018Member |  |  |  |  |  |  |
Number of identical floating rate financing agreements entered into concurrently with French banking partnerships |  |  |  |  |  | 4 luv_NumberOfIdenticalFloatingRateFinancingAgreementsEnteredIntoConcurrentlyWithFrenchBankingPartnerships / us-gaap_DebtInstrumentAxis = luv_CreditAgreementsDue2018Member |  |  |  |  |  |  |
Term |  |  |  |  |  | 13 years 0 months 0 days |  |  |  |  |  |  |
French Credit Agreements due 2018 - 1.06% | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Spread on variable rate |  |  |  |  |  | (45.00%)us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = luv_CreditAgreementsDue2018Member / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |  |  |  |  |  |
5.25% Notes due 2014 |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  |  |  | 350,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_UnsecuredSeniorNotesDue2014Member |
7.375% Debentures due 2027 |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  | 100,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = luv_UnsecuredSeniorNotesDue2027Member |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  | 7.375%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = luv_UnsecuredSeniorNotesDue2027Member |  |  |  |  |  |
7.375% Debentures due 2027 | Treasury Rate |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Spread on variable rate |  |  |  |  |  |  | 20.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = luv_UnsecuredSeniorNotesDue2027Member / us-gaap_VariableRateAxis = luv_TreasuryRateMember |  |  |  |  |  |
Enhanced Equipment Trust Certificate | Fixed-rate 717 Aircraft Notes payable through 2017 - 10.37% | AirTran Airways |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term Debt, Prepayment | 7,000,000 luv_LongtermDebtPrepayment / us-gaap_DebtInstrumentAxis = luv_NotesPayableAircraftFixedRateThrough2017Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_EnhancedEquipmentTrustCertificateMember |  |  |  |  |  |  |  |  |  |  |  | 35,000,000 luv_LongtermDebtPrepayment / us-gaap_DebtInstrumentAxis = luv_NotesPayableAircraftFixedRateThrough2017Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_EnhancedEquipmentTrustCertificateMember
Make Whole Penalty on Debt Extinguishment | 6,000,000 luv_MakeWholePenaltyonDebtExtinguishment / us-gaap_DebtInstrumentAxis = luv_NotesPayableAircraftFixedRateThrough2017Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_EnhancedEquipmentTrustCertificateMember |  |  |  |  |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) | 10.37%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = luv_NotesPayableAircraftFixedRateThrough2017Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_EnhancedEquipmentTrustCertificateMember |  |  |  |  |  |  |  |  |  |  |  |
Unamortized premium |  |  |  |  |  |  |  |  |  |  |  |  | $ 5,000,000 us-gaap_DebtInstrumentUnamortizedPremium / us-gaap_DebtInstrumentAxis = luv_NotesPayableAircraftFixedRateThrough2017Member / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_EnhancedEquipmentTrustCertificateMember
Enhanced Equipment Trust Certificate | Pass Through Certificates due 2022 - 6.24% |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) | 6.24%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = luv_TotalPassThroughCertificatesMember / us-gaap_LongtermDebtTypeAxis = us-gaap_EnhancedEquipmentTrustCertificateMember |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
Name: | invest_DerivativeNotionalAmount
Namespace Prefix: | invest_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Cash set aside for convertible senior notes conversion. + References No definition available. + Details
Name: | luv_CashSetAsideForConversion
Namespace Prefix: | luv_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Debt Instrument, Convertible, Shares Conversion Ratio + References No definition available. + Details
Name: | luv_DebtInstrumentConvertibleSharesConversionRatio
Namespace Prefix: | luv_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Number of Loans Prepaid During Period + References No definition available. + Details
Name: | luv_DebtInstrumentNumberofLoansPrepaidDuringPeriod
Namespace Prefix: | luv_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of long-term debt principal prepayment. + References No definition available. + Details
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- Definition The maximum additional number of assets pledged as collateral in case the Company has obligations related to its fuel derivative instruments with counterparties that exceed certain thresholds + References No definition available. + Details
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- Definition Number of identical floating rate financing agreements entered into concurrently with French banking partnerships. + References No definition available. + Details
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- Definition Number of mortgages on secured aircraft. + References No definition available. + Details
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- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition The amount of debt premium that was originally recognized at the issuance of the instrument that has yet to be amortized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400 + Details
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- Definition The amount of the liability for the conversion option reclassified to stockholders' equity when the embedded option no longer required separation from the host instrument. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 15 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35708913&loc=d3e50896-113970 + Details
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