Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1	$ 1	$ 2	$ 2
Interest cost	131	154	262	307
Expected return on assets	(271)	(252)	(543)	(505)
Special termination benefits			0	0
Settlements	0	4	0	4
Amortization of:
Prior service cost (benefit)	7	7	14	14
Unrecognized net loss (gain)	52	41	105	83
Net periodic benefit income	(80)	(45)	(160)	(95)
Retiree Medical and Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	2	5	3
Interest cost	8	8	14	14
Expected return on assets	(3)	(3)	(6)	(6)
Special termination benefits			139	0
Settlements	0	0	0	0
Amortization of:
Prior service cost (benefit)	(3)	(52)	(7)	(106)
Unrecognized net loss (gain)	(6)	(5)	(11)	(12)
Net periodic benefit income	(1)	(50)	134	(107)
American Airlines, Inc. | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	2	1
Interest cost	130	153	261	306
Expected return on assets	(270)	(251)	(540)	(503)
Special termination benefits			0	0
Settlements	0	4	0	4
Amortization of:
Prior service cost (benefit)	7	7	14	14
Unrecognized net loss (gain)	52	41	104	83
Net periodic benefit income	(80)	(45)	(159)	(95)
American Airlines, Inc. | Retiree Medical and Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	2	5	3
Interest cost	8	8	14	14
Expected return on assets	(3)	(3)	(6)	(6)
Special termination benefits			139	0
Settlements	0	0	0	0
Amortization of:
Prior service cost (benefit)	(3)	(52)	(7)	(106)
Unrecognized net loss (gain)	(6)	(5)	(11)	(12)
Net periodic benefit income	$ (1)	$ (50)	$ 134	$ (107)