Employee Benefit Plans - Components of Net Periodic Benefit Cost (Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1	$ 0	$ 2	$ 1
Interest cost	180	180	547	542
Expected return on assets	(232)	(245)	(696)	(733)
Amortization of:
Prior service cost	0	0	0	0
Unrecognized net loss (gain)	21	26	68	79
Net periodic benefit cost (income)	(30)	(39)	(79)	(111)
Pension Benefits | American Airlines, Inc.
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	0	2	1
Interest cost	179	178	544	539
Expected return on assets	(231)	(243)	(693)	(729)
Amortization of:
Prior service cost	0	0	0	0
Unrecognized net loss (gain)	21	26	68	79
Net periodic benefit cost (income)	(30)	(39)	(79)	(110)
Retiree Medical and Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	8	18	23
Interest cost	18	17	53	51
Expected return on assets	(2)	(2)	(7)	(7)
Amortization of:
Prior service cost	4	3	13	11
Unrecognized net loss (gain)	(6)	(6)	(17)	(19)
Net periodic benefit cost (income)	20	20	60	59
Retiree Medical and Other Postretirement Benefits | American Airlines, Inc.
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	8	18	23
Interest cost	18	17	53	51
Expected return on assets	(2)	(2)	(7)	(7)
Amortization of:
Prior service cost	4	3	13	11
Unrecognized net loss (gain)	(6)	(6)	(17)	(19)
Net periodic benefit cost (income)	$ 20	$ 20	$ 60	$ 59