Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pension Plans [Member]
Components of net periodic benefit cost:
Service cost	$ 28	$ 28	$ 56	$ 56
Interest cost	32	30	63	60
Expected return on plan assets	(54)	(51)	(107)	(101)
Amortization of:
Net actuarial gain	(2)	(1)	(3)	(3)
Prior service credit	(2)	(4)	(5)	(9)
Net periodic benefit cost	2	2	4	3
Other Postretirement Benefit Plans [Member]
Components of net periodic benefit cost:
Service cost	1	1	2	2
Interest cost	3	3	6	6
Expected return on plan assets	0	0	0	0
Amortization of:
Net actuarial gain	(1)	(2)	(2)	(3)
Prior service credit	0	(1)	0	(2)
Net periodic benefit cost	$ 3	$ 1	$ 6	$ 3