Employee Benefit Plans - Components of Net Periodic Benefit Cost (Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits [Member]
Defined benefit plans:
Service cost	$ 3	$ 2	$ 2
Interest cost	674	721	749
Expected return on assets	(905)	(790)	(750)
Settlements	0	1	0
Amortization of:
Prior service cost (benefit)	28	28	28
Unrecognized net loss (gain)	141	144	126
Net periodic benefit cost (income)	(59)	106	155
Retiree Medical And Other Postretirement Benefits [Member]
Defined benefit plans:
Service cost	5	4	3
Interest cost	35	39	47
Expected return on assets	(24)	(21)	(20)
Settlements	0	0	0
Amortization of:
Prior service cost (benefit)	(236)	(237)	(240)
Unrecognized net loss (gain)	(21)	(23)	(17)
Net periodic benefit cost (income)	(241)	(238)	(227)
American Airlines, Inc. [Member] | Pension Benefits [Member]
Defined benefit plans:
Service cost	2	2	2
Interest cost	670	717	746
Expected return on assets	(901)	(786)	(747)
Settlements	0	1	0
Amortization of:
Prior service cost (benefit)	28	28	28
Unrecognized net loss (gain)	140	144	125
Net periodic benefit cost (income)	(61)	106	154
American Airlines, Inc. [Member] | Retiree Medical And Other Postretirement Benefits [Member]
Defined benefit plans:
Service cost	5	4	3
Interest cost	35	39	47
Expected return on assets	(24)	(21)	(20)
Settlements			0
Amortization of:
Prior service cost (benefit)	(236)	(237)	(240)
Unrecognized net loss (gain)	(21)	(23)	(16)
Net periodic benefit cost (income)	$ (241)	$ (238)	$ (226)