Fair Value Instruments - Carrying and Estimated Fair Value of Debt (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Nov. 06, 2014	Dec. 31, 2013	Oct. 31, 2009	Jul. 01, 2009	Apr. 29, 2009	May. 06, 2008	Dec. 31, 2006	Feb. 28, 2005	Feb. 28, 1997
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 3,198	$ 2,713
5.75% Notes due 2016
Debt Instrument [Line Items]
Interest rate stated in the debt agreement (in hundredths)									5.75%
5.75% Notes due 2016 | Unsecured Debt
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 307	$ 313
Interest rate stated in the debt agreement (in hundredths)	5.75%
5.25% Convertible Senior Notes due 2016 | Convertible Debt
Debt Instrument [Line Items]
Interest rate stated in the debt agreement (in hundredths)	5.25%	5.25%		5.25%
5.125% Notes due 2017
Debt Instrument [Line Items]
Interest rate stated in the debt agreement (in hundredths)										5.125%
5.125% Notes due 2017 | Unsecured Debt
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 309	$ 316
Interest rate stated in the debt agreement (in hundredths)	5.125%
French Credit Agreements due 2018 - 1.53% | Notes Payable to Banks
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 25	36
Interest rate stated in the debt agreement (in hundredths)	1.53%
2.75% Unsecured Senior Notes Due 2019
Debt Instrument [Line Items]
Interest rate stated in the debt agreement (in hundredths)			2.75%
2.75% Unsecured Senior Notes Due 2019 | Unsecured Debt
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 303	300
Interest rate stated in the debt agreement (in hundredths)	2.75%
Term Loan Agreement due 2019 - 6.315%
Debt Instrument [Line Items]
Interest rate stated in the debt agreement (in hundredths)							6.315%
Term Loan Agreement due 2019 - 6.315% | Notes Payable to Banks
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 143	178
Interest rate stated in the debt agreement (in hundredths)	6.315%
Term Loan Agreement due 2019 - 4.84%
Debt Instrument [Line Items]
Interest rate stated in the debt agreement (in hundredths)						4.84%
Term Loan Agreement due 2019 - 4.84% | Notes Payable to Banks
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 36	73
Interest rate stated in the debt agreement (in hundredths)	4.84%
2.65% Notes due 2020
Debt Instrument [Line Items]
Interest rate stated in the debt agreement (in hundredths)	2.65%
2.65% Notes due 2020 | Unsecured Debt
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 494	0
Interest rate stated in the debt agreement (in hundredths)	2.65%
Term Loan Agreement due 2020 - 5.223%
Debt Instrument [Line Items]
Interest rate stated in the debt agreement (in hundredths)								5.223%
Term Loan Agreement due 2020 - 5.223% | Notes Payable to Banks
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 329	372
Interest rate stated in the debt agreement (in hundredths)	5.223%
Pass Through Certificates due 2022 - 6.24% | Enhanced Equipment Trust Certificate
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 340	355
Interest rate stated in the debt agreement (in hundredths)	6.24%
7.375% Debentures due 2027
Debt Instrument [Line Items]
Interest rate stated in the debt agreement (in hundredths)											7.375%
7.375% Debentures due 2027 | Unsecured Debt
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 132	134
Interest rate stated in the debt agreement (in hundredths)	7.375%
Level 2 | 5.75% Notes due 2016 | Unsecured Debt
Debt Instrument [Line Items]
Notes Payable, Fair Value	$ 319
Level 2 | 5.25% Convertible Senior Notes due 2016 | Convertible Debt
Debt Instrument [Line Items]
Notes Payable, Fair Value	324
Level 2 | 5.125% Notes due 2017 | Unsecured Debt
Debt Instrument [Line Items]
Notes Payable, Fair Value	321
Level 2 | 2.75% Unsecured Senior Notes Due 2019 | Unsecured Debt
Debt Instrument [Line Items]
Notes Payable, Fair Value	307
Level 2 | 2.65% Notes due 2020 | Unsecured Debt
Debt Instrument [Line Items]
Notes Payable, Fair Value	493
Level 2 | Pass Through Certificates due 2022 - 6.24% | Enhanced Equipment Trust Certificate
Debt Instrument [Line Items]
Notes Payable, Fair Value	382
Level 2 | 7.375% Debentures due 2027 | Unsecured Debt
Debt Instrument [Line Items]
Loans Payable, Fair Value	154
Level 3 | French Credit Agreements due 2018 - 1.53% | Notes Payable to Banks
Debt Instrument [Line Items]
Notes Payable, Fair Value	25
Level 3 | Fixed-rate 737 Aircraft Notes payable through 2018 - 7.02% | Notes Payable to Banks
Debt Instrument [Line Items]
Notes Payable, Fair Value	17
Level 3 | Term Loan Agreement due 2019 - 6.315% | Notes Payable to Banks
Debt Instrument [Line Items]
Loans Payable, Fair Value	147
Level 3 | Term Loan Agreement due 2019 - 4.84% | Notes Payable to Banks
Debt Instrument [Line Items]
Loans Payable, Fair Value	37
Level 3 | Term Loan Agreement due 2020 - 5.223% | Notes Payable to Banks
Debt Instrument [Line Items]
Loans Payable, Fair Value	323
Level 3 | Floating-rate 737 Aircraft Notes payable through 2020 | Notes Payable to Banks
Debt Instrument [Line Items]
Notes Payable, Fair Value	253
AirTran Airways | 5.25% Convertible Senior Notes due 2016
Debt Instrument [Line Items]
Interest rate stated in the debt agreement (in hundredths)					5.25%
AirTran Airways | 5.25% Convertible Senior Notes due 2016 | Convertible Debt
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 111	113
Interest rate stated in the debt agreement (in hundredths)	5.25%
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	$ 17	24
Interest rate stated in the debt agreement (in hundredths)	7.02%
AirTran Airways | Floating-rate 737 Aircraft Notes payable through 2020 | Notes Payable to Banks
Debt Instrument [Line Items]
Debt and Capital Lease Obligations	$ 257	$ 300