Employee Benefit Plans - Schedule of Amounts Recognized in Other Comprehensive Income (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	$ 5,351	$ 5,484
Prior service cost (benefit)	160	188
Total accumulated other comprehensive loss (income), pre-tax	5,511	5,672
Retiree Medical And Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	(388)	(430)
Prior service cost (benefit)	(600)	(837)
Total accumulated other comprehensive loss (income), pre-tax	(988)	(1,267)
American Airlines, Inc. [Member] | Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	5,337	5,472
Prior service cost (benefit)	159	188
Total accumulated other comprehensive loss (income), pre-tax	5,496	5,660
American Airlines, Inc. [Member] | Retiree Medical And Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	(388)	(429)
Prior service cost (benefit)	(600)	(837)
Total accumulated other comprehensive loss (income), pre-tax	$ (988)	$ (1,266)