Employee Benefit Plans - Components of Net Periodic Benefit Cost (Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Benefits [Member]
Defined benefit plans:
Service cost	$ 2	$ 3	$ 2
Interest cost	703	674	721
Expected return on assets	(815)	(905)	(790)
Settlements	0	0	1
Amortization of:
Prior service cost (benefit)	28	28	28
Unrecognized net loss (gain)	150	141	144
Net periodic benefit cost (income)	68	(59)	106
Retiree Medical And Other Postretirement Benefits [Member]
Defined benefit plans:
Service cost	3	5	4
Interest cost	33	35	39
Expected return on assets	(15)	(24)	(21)
Settlements	0	0	0
Amortization of:
Prior service cost (benefit)	(236)	(236)	(237)
Unrecognized net loss (gain)	(31)	(21)	(23)
Net periodic benefit cost (income)	(246)	(241)	(238)
American Airlines, Inc. [Member] | Pension Benefits [Member]
Defined benefit plans:
Service cost	2	2	2
Interest cost	699	670	717
Expected return on assets	(811)	(901)	(786)
Settlements	0	0	1
Amortization of:
Prior service cost (benefit)	28	28	28
Unrecognized net loss (gain)	150	140	144
Net periodic benefit cost (income)	68	(61)	106
American Airlines, Inc. [Member] | Retiree Medical And Other Postretirement Benefits [Member]
Defined benefit plans:
Service cost	3	5	4
Interest cost	33	35	39
Expected return on assets	(15)	(24)	(21)
Settlements			0
Amortization of:
Prior service cost (benefit)	(236)	(236)	(237)
Unrecognized net loss (gain)	(31)	(21)	(23)
Net periodic benefit cost (income)	$ (246)	$ (241)	$ (238)