Employee Benefit Plans (Obligations and Funded Status) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits
Change in benefit obligations:
Benefit obligations at January 1,	$ 12,873	$ 11,950
Service costs	215	226	$ 214
Interest costs	342	363	425
Plan participants’ contributions	0	0
Plan amendments	1	0
Net actuarial (gains) losses	(363)	928
Acquisition, divestitures, settlements and curtailments	(111)	(55)
Benefits paid	(665)	(589)
Effect of foreign currency translation	(110)	50
Benefit obligations at December 31,	12,182	12,873	11,950
Change in plan assets
Estimated fair value of plan assets at January 1,	11,256	10,230
Actual return on plan assets	310	1,491
Acquisition, divestitures and settlements	(35)	(55)
Plan participants’ contributions	0	0
Employer contributions	163	155
Benefits paid	(665)	(589)
Effect of foreign currency translation	(58)	24
Estimated fair value of plan assets at December 31,	10,971	11,256	10,230
Over (under) funded status at December 31,	(1,211)	(1,617)
Amounts recognized in the consolidated balance sheets
Other assets	640	390
Other liabilities	(1,851)	(2,007)
Net amount recognized	(1,211)	(1,617)
Accumulated other comprehensive (income) loss:
Net actuarial (gains) losses	2,416	2,780
Prior service costs (credit)	(55)	(86)
AOCI, before income tax	2,361	2,694
Accumulated benefit obligation	11,934	12,510
Other Postretirement Benefits
Change in benefit obligations:
Benefit obligations at January 1,	1,252	1,289
Service costs	4	5	5
Interest costs	37	42	53
Plan participants’ contributions	32	32
Plan amendments	0	0
Net actuarial (gains) losses	(96)	(15)
Acquisition, divestitures, settlements and curtailments	8	0
Benefits paid	(99)	(101)
Effect of foreign currency translation	0	0
Benefit obligations at December 31,	1,138	1,252	1,289
Change in plan assets
Estimated fair value of plan assets at January 1,	1,492	1,468
Actual return on plan assets	14	89
Acquisition, divestitures and settlements	(1)	0
Plan participants’ contributions	32	32
Employer contributions	5	4
Benefits paid	(99)	(101)
Effect of foreign currency translation	0	0
Estimated fair value of plan assets at December 31,	1,443	1,492	$ 1,468
Over (under) funded status at December 31,	305	240
Amounts recognized in the consolidated balance sheets
Other assets	788	756
Other liabilities	(483)	(516)
Net amount recognized	305	240
Accumulated other comprehensive (income) loss:
Net actuarial (gains) losses	(332)	(327)
Prior service costs (credit)	0	1
AOCI, before income tax	(332)	(326)
Changes to financial assumptions [Member] | Pension Benefits
Change in benefit obligations:
Net actuarial (gains) losses	(389)	851
Changes to financial assumptions [Member] | Other Postretirement Benefits
Change in benefit obligations:
Net actuarial (gains) losses	(34)	103
Changes to demographic assumptions [Member] | Pension Benefits
Change in benefit obligations:
Net actuarial (gains) losses	0	31
Changes to demographic assumptions [Member] | Other Postretirement Benefits
Change in benefit obligations:
Net actuarial (gains) losses	(4)	4
Changes to Plan Experience [Member] | Pension Benefits
Change in benefit obligations:
Net actuarial (gains) losses	26	46
Changes to Plan Experience [Member] | Other Postretirement Benefits
Change in benefit obligations:
Net actuarial (gains) losses	$ (58)	$ (122)