Fair Value Measurements and Other Investments - Other Investments (Details) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2021 USD ($) aircraft $ / shares shares	Dec. 31, 2021 USD ($) aircraft $ / shares shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2017 USD ($)
Schedule of Equity Method Investments [Line Items]
Liabilities incurred to acquire equity securities		$ 88	$ 0	$ 0
China Southern Airlines
Schedule of Equity Method Investments [Line Items]
Equity interest	0.018	0.018			0.027
Equity method investment, initial aggregate value					$ 203
Vertical
Schedule of Equity Method Investments [Line Items]
Equity interest	0.054	0.054
Equity method investment, initial aggregate value	$ 113	$ 113
Payments to acquire equity method investments	$ 25
Equity method investment, number of shares acquired from investee (in shares) | shares	11,250
Liabilities incurred to acquire equity securities	$ 88
Number of aircraft agreed to pre-order | aircraft	250
Purchase option, additional number of aircraft which can be ordered | aircraft	100
Number of warrants to be issued in installments (in shares) | shares	1,750	1,750
Exercise price of warrants (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001
Threshold number of aircraft to be purchased per legally binding commitment | aircraft	50	50
Aggregated number of warrants to be issued (in shares) | shares	8,750	8,750
American Airlines, Inc.
Schedule of Equity Method Investments [Line Items]
Liabilities incurred to acquire equity securities		$ 88	$ 0	$ 0
American Airlines, Inc. | China Southern Airlines
Schedule of Equity Method Investments [Line Items]
Equity interest	0.018	0.018			0.027
Equity method investment, initial aggregate value					$ 203
American Airlines, Inc. | Vertical
Schedule of Equity Method Investments [Line Items]
Equity interest	0.054	0.054
Equity method investment, initial aggregate value	$ 113	$ 113
Payments to acquire equity method investments	$ 25
Equity method investment, number of shares acquired from investee (in shares) | shares	11,250
Liabilities incurred to acquire equity securities	$ 88
Number of aircraft agreed to pre-order | aircraft	250
Purchase option, additional number of aircraft which can be ordered | aircraft	100
Number of warrants to be issued in installments (in shares) | shares	1,750	1,750
Exercise price of warrants (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001
Threshold number of aircraft to be purchased per legally binding commitment | aircraft	50	50
Aggregated number of warrants to be issued (in shares) | shares	8,750	8,750
Republic
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	25.00%	25.00%
Republic | American Airlines, Inc.
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	25.00%	25.00%