Employee Benefit Plans - Schedule of Changes in Fair Value of Plan Assets (Details) - USD ($) $ in Millions		12 Months Ended
	Sep. 30, 2023	Dec. 31, 2023	Dec. 31, 2022
Pension Benefits
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period		$ 11,884	$ 14,691
Actual return (loss) on plan assets		1,368	(1,943)
Employer contributions		73	5
Benefit payments		(894)	(869)
Fair value of plan assets at end of period		12,431	11,884
Funded status at end of period		(1,979)	(2,153)
Payments of required contributions		69
Retiree Medical and  Other Postretirement Benefits
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period		133	167
Actual return (loss) on plan assets		14	(18)
Employer contributions		70	58
Benefit payments		(84)	(74)
Fair value of plan assets at end of period		133	133
Funded status at end of period		(1,192)	(773)
Increase in postretirement benefit obligation	$ 339
American Airlines, Inc. | Pension Benefits
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period		11,821	14,605
Actual return (loss) on plan assets		1,356	(1,924)
Employer contributions		71	4
Benefit payments		(890)	(864)
Fair value of plan assets at end of period		12,358	11,821
Funded status at end of period		(1,956)	(2,127)
Payments of required contributions		67
American Airlines, Inc. | Retiree Medical and  Other Postretirement Benefits
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period		133	167
Actual return (loss) on plan assets		14	(18)
Employer contributions		70	58
Benefit payments		(84)	(74)
Fair value of plan assets at end of period		133	133
Funded status at end of period		$ (1,192)	$ (773)
Increase in postretirement benefit obligation	$ 339