Special Items, Net (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Merger integration expenses	$ 85
Operating special items, net		$ (966)	$ 641	$ 793
Mark-to-market adjustments on equity and other investments, net	(42)	135	(5)	104
Debt refinancing, extinguishment and other, net		35	8	9
Nonoperating special items, net		170	3	113
Income tax special items		0	0	18
Fleet equipment impairment and inventory write-down		1,500
Operating lease, impairment loss		109
Payments for restructuring, salary and medical costs		365
American Airlines, Inc.
Restructuring Cost and Reserve [Line Items]
Merger integration expenses	85
Operating special items, net		(995)	635	787
Mark-to-market adjustments on equity and other investments, net	$ (42)	135	(5)	104
Debt refinancing, extinguishment and other, net		35	16	9
Nonoperating special items, net		170	11	113
Income tax special items		0	0	18
Fleet equipment impairment and inventory write-down		1,500
Operating lease, impairment loss		109
Payments for restructuring, salary and medical costs		365
Mainline
Restructuring Cost and Reserve [Line Items]
PSP1 Financial Assistance		(3,710)	0	0
Fleet impairment		1,484	213	0
Severance expenses		1,408	11	58
Labor contract expenses		228	0	13
Mark-to-market adjustments on bankruptcy obligations, net		(49)	(11)	(76)
Fleet restructuring expenses		0	271	422
Merger integration expenses		0	191	268
Litigation reserve adjustments		0	(53)	45
Intangible asset impairment		0	0	26
Other operating special items, net		(18)	13	31
Operating special items, net		(657)	635	787
Mainline | American Airlines, Inc.
Restructuring Cost and Reserve [Line Items]
PSP1 Financial Assistance		(3,710)	0	0
Fleet impairment		1,484	213	0
Severance expenses		1,408	11	58
Labor contract expenses		228	0	13
Mark-to-market adjustments on bankruptcy obligations, net		(49)	(11)	(76)
Fleet restructuring expenses		0	271	422
Merger integration expenses		0	191	268
Litigation reserve adjustments		0	(53)	45
Intangible asset impairment		0	0	26
Other operating special items, net		(18)	13	31
Operating special items, net		(657)	635	787
Regional Carrier
Restructuring Cost and Reserve [Line Items]
PSP1 Financial Assistance		(444)	0	0
Fleet impairment		117	0	0
Severance expenses		18	0	0
Other operating special items, net		0	6	6
Operating special items, net		(309)	6	6
Regional Carrier | American Airlines, Inc.
Restructuring Cost and Reserve [Line Items]
PSP1 Financial Assistance		(444)	0	0
Fleet impairment		106	0	0
Operating special items, net		$ (338)	$ 0	$ 0