Employee Benefit Plans - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Retiree Medical and Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Special termination benefits		$ 0	$ 410	$ 139	$ 410
Increase in postretirement benefits obligation			410		410
Retiree Medical and Other Postretirement Benefits | American Airlines, Inc.
Defined Benefit Plan Disclosure [Line Items]
Special termination benefits		0	410	139	410
Increase in postretirement benefits obligation			410		410
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Special termination benefits		0	0	0	0
Defined benefit plan, contributed amount	$ 241
Contributions expected to be deferred under CARES Act	130
Pension Benefits | American Airlines, Inc.
Defined Benefit Plan Disclosure [Line Items]
Special termination benefits		$ 0	$ 0	$ 0	$ 0
Defined benefit plan, contributed amount	241
Contributions expected to be deferred under CARES Act	$ 130