XML 77 R64.htm IDEA: XBRL DOCUMENT v2.4.1.9
Fair Value Instruments - Carrying and Estimated Fair Value of Debt (Details) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2006
Dec. 31, 2012
Feb. 28, 2005
Apr. 29, 2009
Jul. 01, 2009
May 06, 2008
Feb. 28, 1997
Oct. 31, 2009
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations $ 2,713us-gaap_DebtAndCapitalLeaseObligations $ 2,842us-gaap_DebtAndCapitalLeaseObligations                
5.75% Notes due 2016                    
Debt Instrument [Line Items]                    
Interest rate stated in the debt agreement (in hundredths)     5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2016Member
             
5.75% Notes due 2016 | Unsecured Debt                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations 313us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2016Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
320us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2016Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
               
Interest rate stated in the debt agreement (in hundredths) 5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2016Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
                 
5.25% Convertible Senior Notes due 2016 | Convertible Debt                    
Debt Instrument [Line Items]                    
Interest rate stated in the debt agreement (in hundredths) 5.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_ConvertibleDebtDue2016Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_ConvertibleDebtMember
5.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_ConvertibleDebtDue2016Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_ConvertibleDebtMember
  5.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_ConvertibleDebtDue2016Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_ConvertibleDebtMember
           
5.125% Notes due 2017                    
Debt Instrument [Line Items]                    
Interest rate stated in the debt agreement (in hundredths)         5.125%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2017Member
         
5.125% Notes due 2017 | Unsecured Debt                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations 316us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2017Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
322us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2017Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
               
Interest rate stated in the debt agreement (in hundredths) 5.125%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2017Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
                 
French Credit Agreements due 2018 - 1.06% | Notes Payable to Banks                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations 36us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_CreditAgreementsDue2018Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
46us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_CreditAgreementsDue2018Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
               
Interest rate stated in the debt agreement (in hundredths) 1.06%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_CreditAgreementsDue2018Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
                 
2.75% Unsecured Senior Notes Due 2019                    
Debt Instrument [Line Items]                    
Interest rate stated in the debt agreement (in hundredths) 2.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2019MemberMember
                 
2.75% Unsecured Senior Notes Due 2019 | Unsecured Debt                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations 300us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2019MemberMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
0us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2019MemberMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
               
Interest rate stated in the debt agreement (in hundredths) 2.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2019MemberMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
                 
Term Loan Agreement due 2019 - 6.315%                    
Debt Instrument [Line Items]                    
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% | Notes Payable to Banks                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations 178us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_TermLoanAgreementDue05062019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
210us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_TermLoanAgreementDue05062019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
               
Interest rate stated in the debt agreement (in hundredths) 6.315%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_TermLoanAgreementDue05062019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
                 
Term Loan Agreement due 2019 - 6.84%                    
Debt Instrument [Line Items]                    
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% | Notes Payable to Banks                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations 73us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_TermLoanAgreementDue07012019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
85us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_TermLoanAgreementDue07012019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
               
Interest rate stated in the debt agreement (in hundredths) 6.84%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_TermLoanAgreementDue07012019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
                 
Term Loan Agreement due 2020 - 5.223%                    
Debt Instrument [Line Items]                    
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% | Notes Payable to Banks                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations 372us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_TermLoanAgreementDue2020Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
413us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_TermLoanAgreementDue2020Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
               
Interest rate stated in the debt agreement (in hundredths) 5.223%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_TermLoanAgreementDue2020Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
                 
Pass Through Certificates due 2022 - 6.24% | Enhanced Equipment Trust Certificate                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations 355us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_TotalPassThroughCertificatesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_EnhancedEquipmentTrustCertificateMember
371us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_TotalPassThroughCertificatesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_EnhancedEquipmentTrustCertificateMember
               
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
                 
7.375% Debentures due 2027                    
Debt Instrument [Line Items]                    
Interest rate stated in the debt agreement (in hundredths)                 7.375%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2027Member
 
7.375% Debentures due 2027 | Unsecured Debt                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations 134us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2027Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
136us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2027Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
               
Interest rate stated in the debt agreement (in hundredths) 7.375%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2027Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
7.375%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2027Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
               
Level 2 | 5.75% Notes due 2016 | Unsecured Debt                    
Debt Instrument [Line Items]                    
Notes Payable, Fair Value 335us-gaap_NotesPayableFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2016Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
                 
Level 2 | 5.25% Convertible Senior Notes due 2016 | Convertible Debt                    
Debt Instrument [Line Items]                    
Notes Payable, Fair Value 318us-gaap_NotesPayableFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= luv_ConvertibleDebtDue2016Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_ConvertibleDebtMember
                 
Level 2 | 5.125% Notes due 2017 | Unsecured Debt                    
Debt Instrument [Line Items]                    
Notes Payable, Fair Value 338us-gaap_NotesPayableFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2017Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
                 
Level 2 | 2.75% Unsecured Senior Notes Due 2019 | Unsecured Debt                    
Debt Instrument [Line Items]                    
Notes Payable, Fair Value 304us-gaap_NotesPayableFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2019MemberMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
                 
Level 2 | Pass Through Certificates due 2022 - 6.24% | Enhanced Equipment Trust Certificate                    
Debt Instrument [Line Items]                    
Notes Payable, Fair Value 410us-gaap_NotesPayableFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= luv_TotalPassThroughCertificatesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_EnhancedEquipmentTrustCertificateMember
                 
Level 2 | 7.375% Debentures due 2027 | Unsecured Debt                    
Debt Instrument [Line Items]                    
Loans Payable, Fair Value 160us-gaap_LoansPayableFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= luv_UnsecuredSeniorNotesDue2027Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_UnsecuredDebtMember
                 
Level 3 | French Credit Agreements due 2018 - 1.06% | Notes Payable to Banks                    
Debt Instrument [Line Items]                    
Notes Payable, Fair Value 36us-gaap_NotesPayableFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= luv_CreditAgreementsDue2018Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
                 
Level 3 | Fixed-rate 737 Aircraft Notes payable through 2018 - 7.02% | Notes Payable to Banks                    
Debt Instrument [Line Items]                    
Notes Payable, Fair Value 25us-gaap_NotesPayableFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= luv_NotesPayableAircraftFixedRateThrough2018Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
                 
Level 3 | Term Loan Agreement due 2019 - 6.315% | Notes Payable to Banks                    
Debt Instrument [Line Items]                    
Loans Payable, Fair Value 178us-gaap_LoansPayableFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= luv_TermLoanAgreementDue05062019Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
                 
Level 3 | Term Loan Agreement due 2019 - 6.84% | Notes Payable to Banks                    
Debt Instrument [Line Items]                    
Loans Payable, Fair Value 79us-gaap_LoansPayableFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= luv_TermLoanAgreementDue07012019Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
                 
Level 3 | Term Loan Agreement due 2020 - 5.223% | Notes Payable to Banks                    
Debt Instrument [Line Items]                    
Loans Payable, Fair Value 367us-gaap_LoansPayableFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= luv_TermLoanAgreementDue2020Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
                 
Level 3 | Floating-rate 737 Aircraft Notes payable through 2020 | Notes Payable to Banks                    
Debt Instrument [Line Items]                    
Notes Payable, Fair Value 293us-gaap_NotesPayableFairValueDisclosure
/ us-gaap_DebtInstrumentAxis
= luv_NotesPayableAircraftFloatingRateThrough2020Member
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
                 
AirTran Airways | 5.25% Convertible Senior Notes due 2016                    
Debt Instrument [Line Items]                    
Interest rate stated in the debt agreement (in hundredths)                   5.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_ConvertibleDebtDue2016Member
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
AirTran Airways | 5.25% Convertible Senior Notes due 2016 | Convertible Debt                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations 113us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_ConvertibleDebtDue2016Member
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_ConvertibleDebtMember
115us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_ConvertibleDebtDue2016Member
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_ConvertibleDebtMember
               
Interest rate stated in the debt agreement (in hundredths) 5.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_ConvertibleDebtDue2016Member
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_ConvertibleDebtMember
                 
AirTran Airways | Fixed-rate 717 Aircraft Notes payable through 2017 - 10.37% | Enhanced Equipment Trust Certificate                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations 0us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_NotesPayableAircraftFixedRateThrough2017Member
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_EnhancedEquipmentTrustCertificateMember
41us-gaap_DebtAndCapitalLeaseObligations
/ 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
                 
AirTran Airways | Fixed-rate 737 Aircraft Notes payable through 2018 - 7.02% | Notes Payable to Banks                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations 24us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_NotesPayableAircraftFixedRateThrough2018Member
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
30us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_NotesPayableAircraftFixedRateThrough2018Member
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
               
Interest rate stated in the debt agreement (in hundredths) 7.02%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= luv_NotesPayableAircraftFixedRateThrough2018Member
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
                 
AirTran Airways | Floating-rate 737 Aircraft Notes payable through 2020 | Notes Payable to Banks                    
Debt Instrument [Line Items]                    
Debt and Capital Lease Obligations $ 300us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_NotesPayableAircraftFloatingRateThrough2020Member
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
$ 340us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_DebtInstrumentAxis
= luv_NotesPayableAircraftFloatingRateThrough2020Member
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember