Employee Benefit Plans (Net Periodic Benefit Costs and Other Changes Recognized in OCI) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other changes in plan assets and benefit obligations recognized in OCI:
Total recognized in OCI	$ (279)	$ (328)	$ (181)
Pension Benefits
Net periodic benefit costs [Abstract]
Service costs	187	215	226
Interest costs	328	342	363
Settlement and curtailment (gains) losses	5	(7)	10
Expected return on plan assets	(516)	(506)	(528)
Amortization of net actuarial (gains) losses	129	162	189
Amortization of prior service costs (credit)	(11)	(12)	(14)
Total net periodic benefit costs (credit)	122	194	246
Other changes in plan assets and benefit obligations recognized in OCI:
Net actuarial (gains) losses	2	(166)	(35)
Prior service costs (credit)	8	1	0
Amortization of net actuarial (gains) losses	(129)	(162)	(189)
Amortization of prior service (costs) credit	11	12	14
Settlement and curtailment (gains) losses	(5)	(10)	(10)
Total recognized in OCI	(120)	(333)	(215)
Total recognized in net periodic benefit costs and OCI	2	(139)	31
Pension Benefits | Accumulated Other Comprehensive Income (Loss) Foreign Currency Translation Adjustments
Other changes in plan assets and benefit obligations recognized in OCI:
Total recognized in OCI	(7)	(8)	5
Other Postretirement Benefits
Net periodic benefit costs [Abstract]
Service costs	4	4	5
Interest costs	34	37	42
Settlement and curtailment (gains) losses	0	1	0
Expected return on plan assets	(55)	(56)	(62)
Amortization of net actuarial (gains) losses	(25)	(39)	(74)
Amortization of prior service costs (credit)	0	0	(3)
Total net periodic benefit costs (credit)	(42)	(53)	(92)
Other changes in plan assets and benefit obligations recognized in OCI:
Net actuarial (gains) losses	(191)	(54)	(42)
Prior service costs (credit)	0	(1)	0
Amortization of net actuarial (gains) losses	25	39	74
Amortization of prior service (costs) credit	0	0	3
Settlement and curtailment (gains) losses	0	10	0
Total recognized in OCI	(166)	(6)	35
Total recognized in net periodic benefit costs and OCI	(208)	(59)	(57)
Other Postretirement Benefits | Accumulated Other Comprehensive Income (Loss) Foreign Currency Translation Adjustments
Other changes in plan assets and benefit obligations recognized in OCI:
Total recognized in OCI	$ 0	$ 0	$ 0