Basis of Presentation and Summary of Significant Accounting Policies - Changes in Loyalty Program Liability (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Movement In Contract With Customer, Liability [Roll Forward]
Beginning balance	$ 12,878
Ending balance	13,423
Loyalty program [Member]
Movement In Contract With Customer, Liability [Roll Forward]
Beginning balance	8,539
Deferral of revenue	3,438
Recognition of revenue	(3,362)
Ending balance	$ 8,615
Inactive period before expiration of mileage credits	18 months
Customer liabilities	$ 3,193	$ 3,267
American Airlines, Inc. [Member]
Movement In Contract With Customer, Liability [Roll Forward]
Beginning balance	12,878
Ending balance	13,423
American Airlines, Inc. [Member] | Loyalty program [Member]
Movement In Contract With Customer, Liability [Roll Forward]
Beginning balance	8,539
Deferral of revenue	3,438
Recognition of revenue	(3,362)
Ending balance	$ 8,615
Inactive period before expiration of mileage credits	18 months
Customer liabilities	$ 3,193	$ 3,267