v3.26.3
Employee Benefit Plans - Components of Net Periodic Benefit Cost (Income) (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Pension Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost $ 1 $ 1 $ 2 $ 2
Interest cost 176 180 529 547
Expected return on assets (230) (232) (689) (696)
Amortization of:        
Prior service cost 0 0 0 0
Unrecognized net loss (gain) 20 21 64 68
Net periodic benefit cost (income) (33) (30) (94) (79)
Pension Benefits | American Airlines, Inc.        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 1 1 2 2
Interest cost 174 179 525 544
Expected return on assets (228) (231) (684) (693)
Amortization of:        
Prior service cost 0 0 0 0
Unrecognized net loss (gain) 20 21 64 68
Net periodic benefit cost (income) (33) (30) (93) (79)
Retiree Medical and Other Postretirement Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 6 6 17 18
Interest cost 16 18 48 53
Expected return on assets (2) (2) (6) (7)
Amortization of:        
Prior service cost 4 4 13 13
Unrecognized net loss (gain) (5) (6) (16) (17)
Net periodic benefit cost (income) 19 20 56 60
Retiree Medical and Other Postretirement Benefits | American Airlines, Inc.        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 6 6 17 18
Interest cost 16 18 48 53
Expected return on assets (2) (2) (6) (7)
Amortization of:        
Prior service cost 4 4 13 13
Unrecognized net loss (gain) (5) (6) (16) (17)
Net periodic benefit cost (income) $ 19 $ 20 $ 56 $ 60