Basis of Presentation and Summary of Significant Accounting Policies - Significant Categories of Reported Operating Revenues (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue from External Customer [Line Items]
Total operating revenues	$ 4,027	$ 3,173	$ 1,622	$ 8,515	$ 11,313	$ 11,911	$ 11,960	$ 10,584	$ 17,337	$ 45,768	$ 44,541
Passenger
Revenue from External Customer [Line Items]
Total operating revenues									14,518	42,010	40,676
Passenger travel
Revenue from External Customer [Line Items]
Total operating revenues									13,456	38,831	37,457
Loyalty revenue - travel
Revenue from External Customer [Line Items]
Total operating revenues									1,062	3,179	3,219
Cargo
Revenue from External Customer [Line Items]
Total operating revenues									769	863	1,013
Other
Revenue from External Customer [Line Items]
Total operating revenues									2,050	2,895	2,852
Loyalty revenue - marketing services
Revenue from External Customer [Line Items]
Total operating revenues									1,825	2,361	2,352
Other revenue
Revenue from External Customer [Line Items]
Total operating revenues									225	534	500
American Airlines, Inc.
Revenue from External Customer [Line Items]
Total operating revenues	$ 4,027	$ 3,172	$ 1,622	$ 8,514	$ 11,312	$ 11,910	$ 11,958	$ 10,581	17,335	45,761	44,530
American Airlines, Inc. | Passenger
Revenue from External Customer [Line Items]
Total operating revenues									14,518	42,010	40,676
American Airlines, Inc. | Passenger travel
Revenue from External Customer [Line Items]
Total operating revenues									13,456	38,831	37,457
American Airlines, Inc. | Loyalty revenue - travel
Revenue from External Customer [Line Items]
Total operating revenues									1,062	3,179	3,219
American Airlines, Inc. | Cargo
Revenue from External Customer [Line Items]
Total operating revenues									769	863	1,013
American Airlines, Inc. | Other
Revenue from External Customer [Line Items]
Total operating revenues									2,048	2,888	2,841
American Airlines, Inc. | Loyalty revenue - marketing services
Revenue from External Customer [Line Items]
Total operating revenues									1,825	2,361	2,352
American Airlines, Inc. | Other revenue
Revenue from External Customer [Line Items]
Total operating revenues									$ 223	$ 527	$ 489