Employee Benefit Plans (Obligations and Funded Status) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Benefits
Change in benefit obligations:
Benefit obligations at January 1,	$ 9,298	$ 12,182
Service costs	143	187	$ 215
Interest costs	474	328	342
Plan participants’ contributions	0	0
Plan amendments	0	8
Net actuarial (gains) losses	299	(2,609)
Acquisition, divestitures, settlements and curtailments	(35)	(45)
Benefits paid	(636)	(630)
Effect of foreign currency translation	(45)	(123)
Benefit obligations at December 31,	9,498	9,298	12,182
Change in plan assets
Estimated fair value of plan assets at January 1,	8,294	10,971
Actual return on plan assets	529	(2,095)
Acquisition, divestitures and settlements	(35)	(38)
Plan participants’ contributions	0	0
Employer contributions	140	152
Benefits paid	(636)	(630)
Effect of foreign currency translation	(22)	(66)
Estimated fair value of plan assets at December 31,	8,270	8,294	10,971
Over (under) funded status at December 31,	(1,228)	(1,004)
Amounts recognized in the consolidated balance sheets
Other assets	229	428
Other liabilities	(1,457)	(1,432)
Net amount recognized	(1,228)	(1,004)
Accumulated other comprehensive (income) loss:
Net actuarial (gains) losses	2,360	2,277
Prior service costs (credit)	(25)	(36)
AOCI, before income tax	2,335	2,241
Accumulated benefit obligation	9,377	9,185
Other Postretirement Benefits
Change in benefit obligations:
Benefit obligations at January 1,	794	1,138
Service costs	3	4	4
Interest costs	43	34	37
Plan participants’ contributions	30	32
Plan amendments	0	0
Net actuarial (gains) losses	(23)	(289)
Acquisition, divestitures, settlements and curtailments	0	0
Benefits paid	(86)	(125)
Effect of foreign currency translation	4	0
Benefit obligations at December 31,	765	794	1,138
Change in plan assets
Estimated fair value of plan assets at January 1,	1,303	1,443
Actual return on plan assets	72	(43)
Acquisition, divestitures and settlements	0	0
Plan participants’ contributions	30	32
Employer contributions	13	(3)
Benefits paid	(86)	(125)
Effect of foreign currency translation	2	(1)
Estimated fair value of plan assets at December 31,	1,334	1,303	$ 1,443
Over (under) funded status at December 31,	569	509
Amounts recognized in the consolidated balance sheets
Other assets	886	796
Other liabilities	(317)	(287)
Net amount recognized	569	509
Accumulated other comprehensive (income) loss:
Net actuarial (gains) losses	(509)	(498)
Prior service costs (credit)	0	0
AOCI, before income tax	(509)	(498)
United States Pension Plan of US Entity, Non Qualified [Member]
Change in benefit obligations:
Benefit obligations at January 1,	1,000
Benefit obligations at December 31,	1,000	1,000
Changes to financial assumptions [Member] | Pension Benefits
Change in benefit obligations:
Net actuarial (gains) losses	(256)	2,600
Changes to financial assumptions [Member] | Other Postretirement Benefits
Change in benefit obligations:
Net actuarial (gains) losses	(8)	276
Changes to demographic assumptions [Member] | Pension Benefits
Change in benefit obligations:
Net actuarial (gains) losses	54
Changes to demographic assumptions [Member] | Other Postretirement Benefits
Change in benefit obligations:
Net actuarial (gains) losses	8
Changes to Plan Experience [Member] | Pension Benefits
Change in benefit obligations:
Net actuarial (gains) losses	(97)	(14)
Changes to Plan Experience [Member] | Other Postretirement Benefits
Change in benefit obligations:
Net actuarial (gains) losses	$ 23	$ 13