Benefit Plans - Schedule of Components of Net Cost (Benefit) for Pension and Other Postretirement Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Defined Benefit Plan Disclosure [Line Items]
Service cost				$ 38
Costs and expenses	$ 10	$ 13	$ 28	6
Remeasurement (gains) losses	(108)	26	(30)	15
Total net (benefit) cost	(98)	39	(2)	21
Pension benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	28	26	79	52
Interest cost	58	59	177	175
Expected return on plan assets	(77)	(74)	(233)	(227)
Costs and expenses	9	11	23	0
Remeasurement of projected benefit obligation	20	233	128	140
Remeasurement of plan assets	(127)	(214)	(158)	(129)
Remeasurement (gains) losses	(107)	19	(30)	11
Total net (benefit) cost	(98)	30	(7)	11
Postretirement benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	2	2	6	7
Amortization of prior service credit	(1)	0	(1)	(1)
Costs and expenses	1	2	5	6
Remeasurement of projected benefit obligation	(1)	7	0	4
Remeasurement of plan assets	0	0	0	0
Remeasurement (gains) losses	(1)	7	0	4
Total net (benefit) cost	$ 0	$ 9	$ 5	$ 10