Basis of Presentation and Summary of Significant Accounting Policies - Passenger Revenue by Geographic Region (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
Airline Destination Disclosure [Line Items]
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
Airline Destination Disclosure [Line Items]
Operating revenues									14,518	42,010	40,676
Passenger | Domestic
Airline Destination Disclosure [Line Items]
Operating revenues									11,765	30,881	29,573
Passenger | Latin America
Airline Destination Disclosure [Line Items]
Operating revenues									1,852	5,047	5,125
Passenger | Atlantic
Airline Destination Disclosure [Line Items]
Operating revenues									654	4,624	4,376
Passenger | Pacific
Airline Destination Disclosure [Line Items]
Operating revenues									247	1,458	1,602
American Airlines, Inc.
Airline Destination Disclosure [Line Items]
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
Airline Destination Disclosure [Line Items]
Operating revenues									14,518	42,010	40,676
American Airlines, Inc. | Passenger | Domestic
Airline Destination Disclosure [Line Items]
Operating revenues									11,765	30,881	29,573
American Airlines, Inc. | Passenger | Latin America
Airline Destination Disclosure [Line Items]
Operating revenues									1,852	5,047	5,125
American Airlines, Inc. | Passenger | Atlantic
Airline Destination Disclosure [Line Items]
Operating revenues									654	4,624	4,376
American Airlines, Inc. | Passenger | Pacific
Airline Destination Disclosure [Line Items]
Operating revenues									$ 247	$ 1,458	$ 1,602