XML 59 R40.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Fair Value Instruments - Carrying and Estimated Fair Value of Debt (Details) $ in Millions | Sep. 30, 2017 USD ($)
--- | ---
French Credit Agreements Due 2018 - 2.15% | Notes Payable to Banks |
Debt Instrument [Line Items] |
Carrying amount of debt | $ 7
Stated interest rate | 2.15%
Fixed-rate 737 Aircraft Notes payable through 2018 - 7.03% | Notes Payable to Banks |
Debt Instrument [Line Items] |
Carrying amount of debt | $ 3
Stated interest rate | 7.03%
2.75% Notes Due 2019 | Unsecured Debt |
Debt Instrument [Line Items] |
Carrying amount of debt | $ 301
Stated interest rate | 2.75%
Term Loan Agreement payable through 2019 - 6.315% | Notes Payable to Banks |
Debt Instrument [Line Items] |
Carrying amount of debt | $ 76
Stated interest rate | 6.315%
Term Loan Agreement payable through 2019 - 4.84% | Notes Payable to Banks |
Debt Instrument [Line Items] |
Carrying amount of debt | $ 19
Stated interest rate | 4.84%
2.65% Notes due 2020 | Unsecured Debt |
Debt Instrument [Line Items] |
Carrying amount of debt | $ 495
Stated interest rate | 2.65%
Term Loan Agreement payable through 2020 - 5.223% | Notes Payable to Banks |
Debt Instrument [Line Items] |
Carrying amount of debt | $ 249
Stated interest rate | 5.223%
737 Aircraft Notes payable through 2020 | Notes Payable to Banks |
Debt Instrument [Line Items] |
Carrying amount of debt | $ 166
Pass Through Certificates due 2022 - 6.24% | Enhanced Equipment Trust Certificate |
Debt Instrument [Line Items] |
Carrying amount of debt | $ 294
Stated interest rate | 6.24%
Term Loan Agreement due 2026 - 2.53% | Notes Payable to Banks |
Debt Instrument [Line Items] |
Carrying amount of debt | $ 215
Stated interest rate | 2.53%
3.00% Notes due 2026 | Unsecured Debt |
Debt Instrument [Line Items] |
Carrying amount of debt | $ 300
Stated interest rate | 3.00%
7.375% Debentures due 2027 | Unsecured Debt |
Debt Instrument [Line Items] |
Carrying amount of debt | $ 128
Stated interest rate | 7.375%
Level 2 | 2.75% Notes Due 2019 | Unsecured Debt |
Debt Instrument [Line Items] |
Notes Payable, Fair Value | $ 305
Level 2 | 2.65% Notes due 2020 | Unsecured Debt |
Debt Instrument [Line Items] |
Notes Payable, Fair Value | 503
Level 2 | Pass Through Certificates due 2022 - 6.24% | Enhanced Equipment Trust Certificate |
Debt Instrument [Line Items] |
Notes Payable, Fair Value | 322
Level 2 | 3.00% Notes due 2026 | Unsecured Debt |
Debt Instrument [Line Items] |
Notes Payable, Fair Value | 296
Level 2 | 7.375% Debentures due 2027 | Unsecured Debt |
Debt Instrument [Line Items] |
Loans Payable, Fair Value | 157
Level 3 | French Credit Agreements Due 2018 - 2.15% | Notes Payable to Banks |
Debt Instrument [Line Items] |
Notes Payable, Fair Value | 7
Level 3 | Fixed-rate 737 Aircraft Notes payable through 2018 - 7.03% | Notes Payable to Banks |
Debt Instrument [Line Items] |
Notes Payable, Fair Value | 3
Level 3 | Term Loan Agreement payable through 2019 - 6.315% | Notes Payable to Banks |
Debt Instrument [Line Items] |
Loans Payable, Fair Value | 77
Level 3 | Term Loan Agreement payable through 2019 - 4.84% | Notes Payable to Banks |
Debt Instrument [Line Items] |
Loans Payable, Fair Value | 20
Level 3 | Term Loan Agreement payable through 2020 - 5.223% | Notes Payable to Banks |
Debt Instrument [Line Items] |
Loans Payable, Fair Value | 252
Level 3 | 737 Aircraft Notes payable through 2020 | Notes Payable to Banks |
Debt Instrument [Line Items] |
Notes Payable, Fair Value | 165
Level 3 | Term Loan Agreement due 2026 - 2.53% | Notes Payable to Banks |
Debt Instrument [Line Items] |
Loans Payable, Fair Value | $ 215

X
- Definition Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value portion of contractual obligation to pay money on demand or on fixed or determinable dates. + References No definition available. + Details
Name: | us-gaap_LoansPayableFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value portion of notes payable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19,20,22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_NotesPayableFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_DebtInstrumentAxis=luv_CreditAgreementsDue2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_NotesPayableToBanksMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=luv_NotesPayableAircraftFixedRateThrough2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=luv_UnsecuredSeniorNotesDue2019MemberMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=luv_TermLoanAgreementDue05062019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=luv_TermLoanAgreementDue07012019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=luv_UnsecuredSeniorNotesDue2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=luv_TermLoanAgreementDue2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=luv_NotesPayableAircraftFloatingRateThrough2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=luv_TotalPassThroughCertificatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_EnhancedEquipmentTrustCertificateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=luv_TermLoanAgreementDue2026Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=luv_UnsecuredSeniorNotesDue2026Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=luv_UnsecuredSeniorNotesDue2027Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |