Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Pension Plans [Member]
Components of net periodic benefit cost:
Service cost	$ 39	$ 41	$ 77	$ 81
Interest cost	21	18	42	36
Expected return on plan assets	(48)	(48)	(96)	(96)
Amortization of:
Net actuarial loss	13	20	26	40
Prior service credit	(5)	(5)	(9)	(9)
Special charges	0	4	0	4
Net periodic benefit cost	20	30	40	56
Other Postretirement Benefit Plans [Member]
Components of net periodic benefit cost:
Service cost	1	1	3	3
Interest cost	2	1	4	3
Expected return on plan assets	0	0	0	0
Amortization of:
Net actuarial loss	0	0	0	0
Prior service credit	(1)	(1)	(2)	(3)
Special charges	0	0	0	0
Net periodic benefit cost	$ 2	$ 1	$ 5	$ 3