Basis of Presentation and Summary of Significant Accounting Policies - Changes in Loyalty Program Liability (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Movement In Contract With Customer, Liability [Roll Forward]
Beginning balance	$ 15,890
Ending balance	15,527
Loyalty program liability
Movement In Contract With Customer, Liability [Roll Forward]
Beginning balance	9,145
Deferral of revenue	3,810
Recognition of revenue	(3,628)
Ending balance	$ 9,327
Inactive period before expiration of mileage credits	24 months
Customer liabilities	$ 3,453	$ 3,169
American Airlines, Inc.
Movement In Contract With Customer, Liability [Roll Forward]
Beginning balance	15,890
Ending balance	15,527
American Airlines, Inc. | Loyalty program liability
Movement In Contract With Customer, Liability [Roll Forward]
Beginning balance	9,145
Deferral of revenue	3,810
Recognition of revenue	(3,628)
Ending balance	$ 9,327
Inactive period before expiration of mileage credits	24 months
Customer liabilities	$ 3,453	$ 3,169