Employee Benefit Plans - Components of Net Periodic Benefit Cost (Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1	$ 1
Interest cost	176	169
Expected return on assets	(204)	(226)
Amortization of:
Prior service cost (benefit)	7	7
Unrecognized net loss (gain)	38	36
Net periodic benefit cost (income)	18	(13)
Retiree Medical and Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1
Interest cost	8	9
Expected return on assets	(4)	(6)
Amortization of:
Prior service cost (benefit)	(59)	(59)
Unrecognized net loss (gain)	(8)	(5)
Net periodic benefit cost (income)	(62)	(60)
American Airlines, Inc. [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1
Interest cost	175	168
Expected return on assets	(203)	(225)
Amortization of:
Prior service cost (benefit)	7	7
Unrecognized net loss (gain)	38	36
Net periodic benefit cost (income)	18	(13)
American Airlines, Inc. [Member] | Retiree Medical and Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1
Interest cost	8	9
Expected return on assets	(4)	(6)
Amortization of:
Prior service cost (benefit)	(59)	(59)
Unrecognized net loss (gain)	(8)	(5)
Net periodic benefit cost (income)	$ (62)	$ (60)