Revenue Recognition - Changes in Loyalty Program Liability (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Movement In Contract With Customer, Liability [Roll Forward]
Beginning balance	$ 13,952
Ending balance	15,645
Loyalty program liability
Movement In Contract With Customer, Liability [Roll Forward]
Beginning balance	9,195
Deferral of revenue	1,544
Recognition of revenue	(1,544)
Ending balance	$ 9,195
Inactive period before expiration of mileage credits	18 months
Deferred revenue, current	$ 2,791	$ 2,033
Revenue recognition term	12 months
American Airlines, Inc.
Movement In Contract With Customer, Liability [Roll Forward]
Beginning balance	$ 13,952
Ending balance	15,645
American Airlines, Inc. | Loyalty program liability
Movement In Contract With Customer, Liability [Roll Forward]
Beginning balance	9,195
Deferral of revenue	1,544
Recognition of revenue	(1,544)
Ending balance	9,195
Deferred revenue, current	$ 2,791	$ 2,033