Quarterly Financial Data - Summarized Financial Data (Details) - USD ($) $ / shares in Units, shares in Thousands, $ 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
Selected Quarterly Financial Information [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
Operating expenses	6,542	6,044	4,108	11,064	10,584	11,103	10,807	10,209	27,758	42,703	41,885
Operating loss	(2,515)	(2,871)	(2,486)	(2,549)	729	808	1,153	375	(10,421)	3,065	2,656
Net income (loss)	$ (2,178)	$ (2,399)	$ (2,067)	$ (2,241)	$ 414	$ 425	$ 662	$ 185	$ (8,885)	$ 1,686	$ 1,412
Loss per share:
Basic and Diluted (in dollars per share)	$ (3.81)	$ (4.71)	$ (4.82)	$ (5.26)
Basic (in dollars per share)					$ 0.95	$ 0.96	$ 1.49	$ 0.41	$ (18.36)	$ 3.80	$ 3.04
Diluted (in dollars per share)					$ 0.95	$ 0.96	$ 1.49	$ 0.41	$ (18.36)	$ 3.79	$ 3.03
Shares used for computation:
Basic and Diluted (in shares)	571,984	509,049	428,807	425,713
Basic (in shares)					434,578	441,915	445,008	451,951	483,888	443,363	464,236
Diluted (in shares)					435,659	442,401	445,587	453,429	483,888	444,269	465,660
American Airlines, Inc.
Selected Quarterly Financial Information [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
Operating expenses	6,465	5,981	4,063	11,050	10,565	11,082	10,831	10,236	27,559	42,714	41,807
Operating loss	(2,438)	(2,809)	(2,441)	(2,536)	747	828	1,127	345	(10,224)	3,047	2,723
Net income (loss)	$ (2,037)	$ (2,276)	$ (1,968)	$ (2,169)	$ 520	$ 508	$ 714	$ 230	$ (8,450)	$ 1,972	$ 1,658