v3.26.1
Benefit Plans - Schedule of Components of Net Cost (Benefit) for Pension and Other Postretirement Plans (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Defined Benefit Plan Disclosure [Line Items]        
Costs and expenses $ 10 $ 9 $ 17 $ 18
Remeasurement (gains) losses (146) 0 (127) 78
Total net (benefit) cost (136) 9 (110) 96
Pension benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 28 26 58 51
Interest cost 59 59 117 119
Expected return on plan assets (79) (78) (161) (156)
Costs and expenses 8 7 14 14
Remeasurement of projected benefit obligation 43 55 (39) 108
Remeasurement of plan assets (190) (54) (87) (31)
Remeasurement (gains) losses (147) 1 (126) 77
Total net (benefit) cost (139) 8 (112) 91
Postretirement benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 0 0 0 0
Interest cost 2 2 4 4
Amortization of prior service credit 0 0 (1) 0
Costs and expenses 2 2 3 4
Remeasurement of projected benefit obligation 1 (1) (1) 1
Remeasurement (gains) losses 1 (1) (1) 1
Total net (benefit) cost $ 3 $ 1 $ 2 $ 5