Employee Benefit Plans (Net Periodic Benefit Costs) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Pension Benefits
Net periodic benefit costs [Abstract]
Service costs	$ 50	$ 56	$ 102	$ 119
Interest costs	82	83	163	161
Curtailment (gains) losses	0	(17)	0	(17)
Expected return on plan assets	(129)	(125)	(258)	(257)
Amortization of net actuarial (gains) losses	30	39	61	77
Amortization of prior service costs (credit)	(3)	(1)	(6)	(5)
Net periodic benefit costs (credit)	30	35	62	78
Other Postretirement Benefits
Net periodic benefit costs [Abstract]
Service costs	1	1	2	2
Interest costs	9	10	17	18
Curtailment (gains) losses	0	0	0	0
Expected return on plan assets	(15)	(14)	(28)	(28)
Amortization of net actuarial (gains) losses	(6)	(7)	(12)	(27)
Amortization of prior service costs (credit)	0	0	0	0
Net periodic benefit costs (credit)	$ (11)	$ (10)	$ (21)	$ (35)