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Long-term Debt (Details) |  |  |  |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Oct. 31, 2016 USD ($) Mortgages | Apr. 29, 2009 USD ($) Mortgages | May 06, 2008 USD ($) Mortgages | Feb. 28, 1997 USD ($) | Oct. 31, 2009 USD ($) $ / shares shares | Dec. 31, 2004 USD ($) Mortgages Agreements | Dec. 31, 2016 USD ($) Mortgages aircraft shares | Dec. 31, 2015 USD ($) | Dec. 31, 2014 USD ($) | Nov. 04, 2016 USD ($) | Sep. 30, 2016 USD ($) aircraft | Nov. 05, 2015 USD ($) | Nov. 06, 2014 USD ($) | Jul. 01, 2009 USD ($) Mortgages | Oct. 03, 2007 USD ($) Mortgages | Dec. 31, 2006 USD ($) | Feb. 28, 2005 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Encumbered Aircraft Released | aircraft |  |  |  |  |  |  | 1 |  |  |  |  |  |  |  |  |  |
Encumbered Aircraft Remaining | aircraft |  |  |  |  |  |  | 4 |  |  |  |  |  |  |  |  |  |
Repayments of Convertible Debt |  |  |  |  |  |  | $ 68,000,000 | $ 0 | $ 0 |  |  |  |  |  |  |  |
Letters of Credit Outstanding Amount |  |  |  |  |  |  | 179,000,000 |  |  |  |  |  |  |  |  |  |
Net book value of assets pledged as collateral for the Company's secured borrowings, primarily aircraft and engines |  |  |  |  |  |  | 2,800,000,000 |  |  |  |  |  |  |  |  |  |
Net book value of additional assets pledged as collateral in case obligations related to fuel derivatives exceed certain thresholds |  |  |  |  |  |  | 2,700,000,000.0 |  |  |  |  |  |  |  |  |  |
Long-term Debt, by Maturity [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
2017 |  |  |  |  |  |  | 555,000,000 |  |  |  |  |  |  |  |  |  |
2018 |  |  |  |  |  |  | 323,000,000 |  |  |  |  |  |  |  |  |  |
2019 |  |  |  |  |  |  | 573,000,000 |  |  |  |  |  |  |  |  |  |
2020 |  |  |  |  |  |  | 797,000,000 |  |  |  |  |  |  |  |  |  |
2021 |  |  |  |  |  |  | 148,000,000 |  |  |  |  |  |  |  |  |  |
Thereafter |  |  |  |  |  |  | 926,000,000 |  |  |  |  |  |  |  |  |  |
AirTran Airways | Interest rate derivatives |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount |  |  |  |  |  |  | $ 166,000,000 |  |  |  |  |  |  |  |  |  |
AirTran Airways | Maximum | Interest rate derivatives |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  | 6.435% |  |  |  |  |  |  |  |  |  |
737 Aircraft Notes payable through 2020 | AirTran Airways |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft | Mortgages |  |  |  |  |  |  | 18 |  |  |  |  |  |  |  |  |  |
Weighted average interest rate |  |  |  |  |  |  | 2.40% |  |  |  |  |  |  |  |  |  |
Fixed-rate 737 Aircraft Notes payable through 2018 - 7.03% | AirTran Airways |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft | aircraft |  |  |  |  |  |  | 2 |  |  |  |  |  |  |  |  |  |
Weighted average interest rate |  |  |  |  |  |  | 7.03% |  |  |  |  |  |  |  |  |  |
5.25% Convertible Senior Notes due 2016 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Conversion ratio | shares |  |  |  |  | 54.5143 |  |  |  |  |  |  |  |  |  |  |  |
Conversion price | $ / shares |  |  |  |  | $ 615.16 |  |  |  |  |  |  |  |  |  |  |  |
Debt Conversion, Converted Instrument, Shares Issued | shares |  |  |  |  |  |  | 6,000,000 |  |  |  |  |  |  |  |  |  |
Repayments of Convertible Debt |  |  |  |  |  |  | $ 68,000,000 |  |  |  |  |  |  |  |  |  |
5.25% Convertible Senior Notes due 2016 | AirTran Airways |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  | $ 115,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  | 5.25% |  |  |  |  |  |  |  |  |  |  |  |
Conversion ratio | shares |  |  |  |  | 168.6576 |  |  |  |  |  |  |  |  |  |  |  |
Unsecured Senior Notes Due 2026 - 3.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  | $ 300,000,000 |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  |  | 3.00% |  |  |  |  |  |  |
Term Loan Agreement Due 2026 - 2.36% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft | Mortgages | 7 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) | 2.36% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term Loan Agreement Due 2026 - 2.36% | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Spread on variable rate | 1.10% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term Loan Agreement Due 2026 - 2.36% | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt | $ 215,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term Loan Agreement Due 2018 to 2021 - 7.94% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  |  | $ 20,000,000 |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  |  |  | 7.94% |  |  |  |  |  |
Aircraft Equity Buyouts | aircraft |  |  |  |  |  |  |  |  |  |  | 4 |  |  |  |  |  |
2.65% Notes due 2020 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  |  |  | $ 500,000,000 |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  |  |  |  | 2.65% |  |  |  |  |
2.75% Unsecured Senior Notes Due 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  |  |  |  | $ 300,000,000 |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  |  |  |  |  | 2.75% |  |  |  |
Term Loan Agreement payable through 2019 - 4.84% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft | Mortgages |  |  |  |  |  |  |  |  |  |  |  |  |  | 5 |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  |  |  |  |  |  | 4.84% |  |  |
Debt Instrument, Prepayment Amount |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 24,000,000 |  |  |
Term Loan Agreement payable through 2019 - 4.84% | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 124,000,000 |  |  |
Term Loan Agreement payable through 2019 - 6.315% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft | Mortgages |  | 14 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  | 6.315% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term Loan Agreement payable through 2019 - 6.315% | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Spread on variable rate |  | 3.30% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term Loan Agreement payable through 2019 - 6.315% | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  | $ 332,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term Loan Agreement payable through 2020 - 5.223% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft | Mortgages |  |  | 21 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  | $ 600,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  | 5.223% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term Loan Agreement payable through 2020 - 5.223% | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Spread on variable rate |  |  | 0.95% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Pass Through Certificates due 2022 - 6.24% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft | Mortgages |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 16 |  |
Face amount of debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 500,000,000 |  |
Pass Through Certificates due 2022 - 6.24% | Interest rate derivatives | Cash Flow Hedging |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 20,000,000 |  |
Pass Through Certificates Series A |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 412,000,000 |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6.15% |  |
Pass Through Certificates Series B |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 88,000,000 |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6.65% |  |
5.75% Notes due 2016 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 300,000,000 |
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.75% |
5.125% Notes due 2017 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 300,000,000
Interest rate stated in the debt agreement (in hundredths) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.125%
French Credit Agreements due 2018 - 2.23% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of mortgages on secured aircraft | Mortgages |  |  |  |  |  | 4 |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  |  |  | $ 112,000,000 |  |  |  |  |  |  |  |  |  |  |
Number of identical floating rate financing agreements entered into concurrently with French banking partnerships | Agreements |  |  |  |  |  | 4 |  |  |  |  |  |  |  |  |  |  |
Term |  |  |  |  |  | 13 years |  |  |  |  |  |  |  |  |  |  |
French Credit Agreements due 2018 - 2.23% | LIBOR |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Spread on variable rate |  |  |  |  |  | (0.45%) |  |  |  |  |  |  |  |  |  |  |
7.375% Debentures due 2027 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Face amount of debt |  |  |  | $ 100,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate stated in the debt agreement (in hundredths) |  |  |  | 7.375% |  |  |  |  |  |  |  |  |  |  |  |  |
7.375% Debentures due 2027 | Treasury Rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Spread on variable rate |  |  |  | 20.00% |  |  |  |  |  |  |  |  |  |  |  |  |
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% |  |  |  |  |  |  |  |  |  |
B-737-700 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum additional number of assets pledged as collateral in case obligations related to fuel derivatives exceed certain thresholds | aircraft |  |  |  |  |  |  | 82 |  |  |  |  |  |  |  |  |  |
B-737-800 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum additional number of assets pledged as collateral in case obligations related to fuel derivatives exceed certain thresholds | aircraft |  |  |  |  |  |  | 30 |  |  |  |  |  |  |  |  |  |

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
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- Definition Debt Instrument, Convertible, Shares Conversion Ratio + References No definition available. + Details
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- Definition Debt Instrument, Prepayment Amount + References No definition available. + Details
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- Definition Encumbered Aircraft Released + References No definition available. + Details
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- Definition Encumbered Aircraft Remaining + References No definition available. + Details
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- Definition luv_TermLoanAgreementDue2018to2021EquityBuyout + 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 The net book value of additional 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 The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586 + Details
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- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
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- Definition The price per share of the conversion feature embedded in the debt instrument. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870 + Details
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