Employee Benefit Plans - Components of Net Periodic Benefit Cost (Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1	$ 1
Interest cost	177	183
Expected return on assets	(230)	(232)
Amortization of:
Prior service cost	0	0
Unrecognized net loss (gain)	22	24
Net periodic benefit cost (income)	(30)	(24)
Pension Benefits | American Airlines, Inc.
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1
Interest cost	175	182
Expected return on assets	(228)	(231)
Amortization of:
Prior service cost	0	0
Unrecognized net loss (gain)	22	24
Net periodic benefit cost (income)	(30)	(24)
Retiree Medical and Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	6
Interest cost	16	18
Expected return on assets	(2)	(2)
Amortization of:
Prior service cost	4	4
Unrecognized net loss (gain)	(5)	(6)
Net periodic benefit cost (income)	19	20
Retiree Medical and Other Postretirement Benefits | American Airlines, Inc.
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	6
Interest cost	16	18
Expected return on assets	(2)	(2)
Amortization of:
Prior service cost	4	4
Unrecognized net loss (gain)	(5)	(6)
Net periodic benefit cost (income)	$ 19	$ 20