v3.26.3
Benefit Plans - Schedule of Components of Net Cost (Benefit) for Pension and Other Postretirement Plans (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Defined Benefit Plan Disclosure [Line Items]        
Costs and expenses $ 7 $ 10 $ 24 $ 28
Remeasurement (gains) losses (28) (108) (155) (30)
Total net benefit (21) (98) (131) (2)
Pension benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 29 28 87 79
Interest cost 59 58 176 177
Expected return on plan assets (82) (77) (243) (233)
Costs and expenses 6 9 20 23
Remeasurement of projected benefit obligation (244) 20 (283) 128
Remeasurement of plan assets 222 (127) 135 (158)
Remeasurement (gains) losses (22) (107) (148) (30)
Total net benefit (16) (98) (128) (7)
Postretirement benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 0 0 0 0
Interest cost 1 2 5 6
Amortization of prior service credit 0 (1) (1) (1)
Costs and expenses 1 1 4 5
Remeasurement of projected benefit obligation (6) (1) (7) 0
Remeasurement (gains) losses (6) (1) (7) 0
Total net benefit $ (5) $ 0 $ (3) $ 5