v3.25.2
Employee Benefit Plans (Components of Provision for Net Periodic Benefit (Credit) Cost) (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Pension Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost $ 19 $ 22 $ 38 $ 44
Interest cost 109 108 217 217
Expected return on plan assets (169) (207) (338) (411)
Amortization of prior service cost (credit) 0 0 0 0
Amortization of net actuarial (gain) loss 0 22 0 (148)
Curtailments 0 (25) 0 (56)
Plan amendment 0 0 0 22
Net periodic benefit (credit) cost (41) (80) (83) (332)
Other Postretirement Benefits        
Defined Benefit Plan Disclosure [Line Items]        
Service cost 2 3 5 6
Interest cost 15 14 29 28
Expected return on plan assets (40) (43) (80) (85)
Amortization of prior service cost (credit) (7) (9) (13) (18)
Amortization of net actuarial (gain) loss 0 (37) 0 (69)
Curtailments 0 0 0 (4)
Plan amendment 0 0 0 0
Net periodic benefit (credit) cost $ (30) $ (72) $ (59) $ (142)