Employee Benefit Plans - Schedule of Amounts Recognized in Other Comprehensive Income (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	$ 6,700	$ 5,680
Prior service cost (benefit)	75	104
Total accumulated other comprehensive loss (income), pre-tax	6,775	5,784
Retiree Medical and  Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	(358)	(426)
Prior service cost (benefit)	(181)	(120)
Total accumulated other comprehensive loss (income), pre-tax	(539)	(546)
American Airlines, Inc. | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	6,679	5,662
Prior service cost (benefit)	75	102
Total accumulated other comprehensive loss (income), pre-tax	6,754	5,764
American Airlines, Inc. | Retiree Medical and  Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain)	(358)	(426)
Prior service cost (benefit)	(181)	(120)
Total accumulated other comprehensive loss (income), pre-tax	$ (539)	$ (546)