Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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Face (par) amount of debt instrument at time of issuance.

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Long-term Debt (Details)	12 Months Ended
Long-term Debt (Details)	Dec. 31, 2018 USD ($) aircraft Mortgages Agreements	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Debt Instrument [Line Items]
Encumbered Aircraft Released \| aircraft	1
Encumbered Aircraft Remaining \| aircraft	4
Repayments of Convertible Debt	$ 0	$ 0	$ 68,000,000
Letters of Credit Outstanding Amount	170,000,000
Net book value of assets pledged as collateral for the Company's secured borrowings, primarily aircraft and engines	1,500,000,000
Net book value of additional assets pledged as collateral in case obligations related to fuel derivatives exceed certain thresholds	2,100,000,000
Long-term Debt, by Maturity [Abstract]
2019	590,000,000
2020	821,000,000
2021	172,000,000
2022	477,000,000
2023	105,000,000
Thereafter	1,100,000,000
AirTran Airways \| Interest rate derivatives
Debt Instrument [Line Items]
Notional amount	$ 57,000,000
AirTran Airways \| Maximum \| Interest rate derivatives
Debt Instrument [Line Items]
Interest rate stated in the debt agreement (in hundredths)	5.91%
French Credit Agreements due June 2018 - 2.54%
Debt Instrument [Line Items]
Face amount of debt	$ 112,000,000
Interest rate stated in the debt agreement (in hundredths)		2.54%
Number of identical floating rate financing agreements entered into concurrently with French banking partnerships \| Agreements	4
Term	13 years
Fixed-rate 737 Aircraft Notes payable through January 2018 - 7.03%
Debt Instrument [Line Items]
Interest rate stated in the debt agreement (in hundredths)		7.03%
2.75% Unsecured Senior Notes Due November 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 May 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 May 2019 - 6.315% \| LIBOR
Debt Instrument [Line Items]
Spread on variable rate	3.30%
Term Loan Agreement payable through May 2019 - 6.315% \| Maximum
Debt Instrument [Line Items]
Face amount of debt	$ 332,000,000
Term Loan Agreement payable through July 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 July 2019 - 4.84% \| Maximum
Debt Instrument [Line Items]
Face amount of debt	124,000,000
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%
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%
737 Aircraft Notes payable through 2020 \| AirTran Airways
Debt Instrument [Line Items]
Number of mortgages on secured aircraft \| Mortgages	9
Weighted average interest rate	4.06%
Notes Payable Aircraft Fixed Rate Through 2019 [Member] \| AirTran Airways
Debt Instrument [Line Items]
Number of mortgages on secured aircraft \| Mortgages	1
Unsecured Senior Notes Due 2022 - 2.75%
Debt Instrument [Line Items]
Face amount of debt	$ 300,000,000
Interest rate stated in the debt agreement (in hundredths)	2.75%
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%
Term Loan Agreement Due 2026 - 3.88%
Debt Instrument [Line Items]
Number of mortgages on secured aircraft \| Mortgages	7
Interest rate stated in the debt agreement (in hundredths)	3.88%
Term Loan Agreement Due 2026 - 3.88% \| LIBOR
Debt Instrument [Line Items]
Spread on variable rate	1.10%
Term Loan Agreement Due 2026 - 3.88% \| Maximum
Debt Instrument [Line Items]
Face amount of debt	$ 215,000,000
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%
Unsecured Senior Notes Due 2027 - 3.45%
Debt Instrument [Line Items]
Face amount of debt	$ 300,000,000
Interest rate stated in the debt agreement (in hundredths)	3.45%
Unsecured Senior Notes Due 2027 - 3.45% \| Treasury Rate
Debt Instrument [Line Items]
Spread on variable rate	20.00%
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%
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	74
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	24