v3.26.1
Pension Plans and Other Post-Retirement Benefit Plans - Components of Net Periodic Benefit Cost for Pension Plans and Other Post-Retirement Benefit Plans (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Pension Plans [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Service cost $ 5 $ 4 $ 9 $ 10
Interest expense 39 44 77 86
Expected return on plan assets (48) (49) (94) (98)
Amortization of net actuarial gain 0 0 0 0
Settlement loss 7 0 7 1
Net periodic benefit cost 3 (1) (1) (1)
Other Post-Retirement Benefit Plans [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 0 0 0 0
Interest expense 3 3 4 4
Expected return on plan assets 0 0 0 0
Amortization of net actuarial gain (1) (1) (1) 0
Settlement loss 0 0 0 0
Net periodic benefit cost $ 2 $ 2 $ 3 $ 4