v3.26.1
Employee Benefit Plans - PAC (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Other Postretirement Plans        
Defined Benefit Plan Disclosure [Line Items]        
Service cost $ 1 $ 1 $ 2 $ 2
Interest cost 6 7 13 14
Expected return on plan assets (8) (9) (18) (18)
Net amortization (1) (2) (2) (3)
Net periodic benefit cost (2) (3) (5) (5)
United States | Pension Plan        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 3 3 6 6
Interest cost 25 28 50 54
Expected return on plan assets (29) (31) (60) (61)
Net amortization 3 2 5 4
Net periodic benefit cost 2 2 1 3
PAC | Other Postretirement Plans        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 0 0 0 0
Interest cost 2 2 5 5
Expected return on plan assets (2) (3) (5) (6)
Net amortization 0 0 (1) (1)
Net periodic benefit cost 0 (1) (1) (2)
PAC | United States | Pension Plan        
Defined Benefit Plan Disclosure [Line Items]        
Interest cost 8 10 17 19
Expected return on plan assets (10) (12) (21) (23)
Net amortization 3 2 5 4
Net periodic benefit cost $ 1 $ 0 $ 1 $ 0