Employee Benefit Plans - Schedule of Accumulated Benefit Obligations Exceeding Fair Value of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 18,910	$ 19,812
Accumulated benefit obligation	18,899	19,799
Fair value of plan assets	14,691	13,557
Retiree Medical and  Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated postretirement benefit obligation	1,098	1,046
Fair value of plan assets	167	170
American Airlines, Inc. | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	18,791	19,690
Accumulated benefit obligation	18,782	19,678
Fair value of plan assets	14,605	13,477
American Airlines, Inc. | Retiree Medical and  Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated postretirement benefit obligation	1,098	1,046
Fair value of plan assets	$ 167	$ 170