v3.26.3
Pension Plans and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Costs (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Pension Plans, Defined Benefit [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Service cost $ 4 $ 4 $ 12 $ 12
Interest cost 9 8 27 26
Expected return on plan assets (11) (11) (33) (33)
Net loss recognition 0 1 0 2
Net periodic benefit cost 2 2 6 7
Other Postretirement Benefits [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 1 1 2 2
Interest cost 1 2 5 5
Expected return on plan assets (1) (1) (3) (3)
Net loss recognition 0 0 0 0
Net periodic benefit cost $ 1 $ 2 $ 4 $ 4