Quarterly Financial Data - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Operating and nonoperating special items, net	$ 108	$ 195
Fleet restructuring expenses	39	94	$ 271	$ 422	$ 232
Merger integration expenses	85	81	191	268	273
Severance costs		37	11	58	0
Mark-to-market net unrealized gains (losses) on equity investments	42	(22)	5	(104)	0
Net credit (charge) resulting from mark-to-market adjustments for bankruptcy obligations		(37)	(11)	(76)	27
American Airlines, Inc. [Member]
Restructuring Cost and Reserve [Line Items]
Operating and nonoperating special items, net	108	190
Fleet restructuring expenses	39	94	271	422	232
Merger integration expenses	85	81	191	268	273
Severance costs		37	11	58	0
Mark-to-market net unrealized gains (losses) on equity investments	$ 42	(22)	5	(104)	0
Net credit (charge) resulting from mark-to-market adjustments for bankruptcy obligations		$ 37	$ (11)	$ (76)	$ 27