v3.26.3
Benefit Plans (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
Interest cost 9 12 31 34
Expected return on plan assets (15) (16) (46) (46)
Amortization of unrecognized net loss 2 2 5 6
Settlements 1
Regulatory asset decrease 1 1
Net periodic benefit (3) (2) (8) (4)
Other Postretirement Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Interest cost 1 1
Expected return on plan assets (1) (2) (2)
Amortization of unrecognized prior service cost 1
Net periodic benefit $ 0 $ (1) $ 0 $ (1)