Impact of New Accounting Standard (Impact by Segment) (Details) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits		$ 41,231	$ 35,689
Deferred policy acquisition costs		4,617	4,128
Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits			35,689	$ 47,449
Deferred policy acquisition costs			4,128	3,860
Previously Reported | Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits			35,220	35,782
Deferred policy acquisition costs			3,974	3,690
Revision of Prior Period, Change in Accounting Principle, Adjustment | Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits			469	11,667
Deferred policy acquisition costs			154	170
Life Insurance Product Line [Member] | Americas [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits		10,947	9,474
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance		(767)	(421)
Liability for Future Policy Benefit, after Reinsurance		10,180	9,053
Deferred policy acquisition costs			2,087	1,947
Life Insurance Product Line [Member] | Americas [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits				14,042	$ 17,632
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance				(697)	(1,123)
Liability for Future Policy Benefit, after Reinsurance				13,345	16,509
Deferred policy acquisition costs				1,947
Life Insurance Product Line [Member] | Canada Segment Reporting Information [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits		4,457	3,951
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance		(298)	(265)
Liability for Future Policy Benefit, after Reinsurance		4,159	3,686
Deferred policy acquisition costs			171	191
Life Insurance Product Line [Member] | Canada Segment Reporting Information [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits				5,555	6,364
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance				(367)	(386)
Liability for Future Policy Benefit, after Reinsurance				5,188	5,978
Deferred policy acquisition costs				191
Life Insurance Product Line [Member] | EMEA [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits		1,209	1,041
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance		(34)	(31)
Liability for Future Policy Benefit, after Reinsurance		1,175	1,010
Deferred policy acquisition costs			294	270
Life Insurance Product Line [Member] | EMEA [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits				1,389	2,670
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance				(34)	(85)
Liability for Future Policy Benefit, after Reinsurance				1,355	2,585
Deferred policy acquisition costs				270
Life Insurance Product Line [Member] | Asia Pacific [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits		2,664	2,348
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance		(122)	(100)
Liability for Future Policy Benefit, after Reinsurance		2,542	2,248
Deferred policy acquisition costs			1,043	1,056
Life Insurance Product Line [Member] | Asia Pacific [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits				3,011	4,419
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance				(116)	(212)
Liability for Future Policy Benefit, after Reinsurance				2,895	4,207
Deferred policy acquisition costs				1,056
Life Insurance Product Line [Member] | Previously Reported | Americas [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					10,444
Life Insurance Product Line [Member] | Previously Reported | Canada Segment Reporting Information [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					3,477
Life Insurance Product Line [Member] | Previously Reported | EMEA [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					1,379
Life Insurance Product Line [Member] | Previously Reported | Asia Pacific [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					3,568
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Accounting Standards Update 2018-12 | Other Segments | Retained Earnings Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					1,462
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Americas [Member] | Accounting Standards Update 2018-12 | Other Segments | Retained Earnings Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[1]				896
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Americas [Member] | Accounting Standards Update 2018-12 | Other Segments | Effect Of Changes In Discount Rate Assumptions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					4,542
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Americas [Member] | Accounting Standards Update 2018-12 | Other Segments | Reclassification of Claims and Benefits payable
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[2]				1,750
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Canada Segment Reporting Information [Member] | Accounting Standards Update 2018-12 | Other Segments | Retained Earnings Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[1]				33
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Canada Segment Reporting Information [Member] | Accounting Standards Update 2018-12 | Other Segments | Effect Of Changes In Discount Rate Assumptions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					2,651
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Canada Segment Reporting Information [Member] | Accounting Standards Update 2018-12 | Other Segments | Reclassification of Claims and Benefits payable
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[2]				203
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | EMEA [Member] | Accounting Standards Update 2018-12 | Other Segments | Retained Earnings Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[1]				70
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | EMEA [Member] | Accounting Standards Update 2018-12 | Other Segments | Effect Of Changes In Discount Rate Assumptions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					320
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | EMEA [Member] | Accounting Standards Update 2018-12 | Other Segments | Reclassification of Claims and Benefits payable
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[2]				901
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Asia Pacific [Member] | Accounting Standards Update 2018-12 | Other Segments | Retained Earnings Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[1]				463
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Asia Pacific [Member] | Accounting Standards Update 2018-12 | Other Segments | Effect Of Changes In Discount Rate Assumptions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					(772)
Life Insurance Product Line [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Asia Pacific [Member] | Accounting Standards Update 2018-12 | Other Segments | Reclassification of Claims and Benefits payable
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[2]				1,160
Insurance, Other [Member] | Americas [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits		5,228	3,819
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance		(913)	0
Liability for Future Policy Benefit, after Reinsurance		4,315	3,819
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change		253	263	254
Market Risk Benefit, Reinsurance Recoverable, after Allowance		0	0
Market Risk Benefit, after Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change		249	247	262
Deferred policy acquisition costs			341	312
Insurance, Other [Member] | Americas [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits				4,947	5,883
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance				0	0
Liability for Future Policy Benefit, after Reinsurance				4,947	5,883
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change				254	266	$ 311
Market Risk Benefit, Reinsurance Recoverable, after Allowance				0	0
Market Risk Benefit, after Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change				262	266	$ 266
Deferred policy acquisition costs				312	368
Insurance, Other [Member] | Canada Segment Reporting Information [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits		29	54
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance		0	0
Liability for Future Policy Benefit, after Reinsurance		29	54
Deferred policy acquisition costs			0	0
Insurance, Other [Member] | Canada Segment Reporting Information [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits				81	49
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance				0	0
Liability for Future Policy Benefit, after Reinsurance				81	49
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Market Risk Benefit, Reinsurance Recoverable, after Allowance					0
Market Risk Benefit, after Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Deferred policy acquisition costs				0	0
Insurance, Other [Member] | EMEA [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits		5,453	4,634
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance		0	0
Liability for Future Policy Benefit, after Reinsurance		5,453	4,634
Deferred policy acquisition costs			0	0
Insurance, Other [Member] | EMEA [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits				6,729	6,991
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance				0	0
Liability for Future Policy Benefit, after Reinsurance				6,729	6,991
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Market Risk Benefit, Reinsurance Recoverable, after Allowance					0
Market Risk Benefit, after Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Deferred policy acquisition costs				0	0
Insurance, Other [Member] | Asia Pacific [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits		5,190	4,496
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance		0	0
Liability for Future Policy Benefit, after Reinsurance		$ 5,190	4,496
Deferred policy acquisition costs			$ 188	81
Insurance, Other [Member] | Asia Pacific [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits				5,014	1,887
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance				0	0
Liability for Future Policy Benefit, after Reinsurance				5,014	1,887
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Market Risk Benefit, Reinsurance Recoverable, after Allowance					0
Market Risk Benefit, after Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Deferred policy acquisition costs				$ 81	41
Insurance, Other [Member] | Previously Reported | Americas [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					5,037
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Deferred policy acquisition costs					254
Insurance, Other [Member] | Previously Reported | Canada Segment Reporting Information [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					16
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Deferred policy acquisition costs					0
Insurance, Other [Member] | Previously Reported | EMEA [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					5,657
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Deferred policy acquisition costs					0
Insurance, Other [Member] | Previously Reported | Asia Pacific [Member] | Accounting Standards Update 2018-12 | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					1,874
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Deferred policy acquisition costs					41
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Accounting Standards Update 2018-12 | Other Segments | Retained Earnings Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					284
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Americas [Member] | Accounting Standards Update 2018-12 | Other Segments | Retained Earnings Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[3]				0
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					72
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Americas [Member] | Accounting Standards Update 2018-12 | Other Segments | Effect Of Changes In Discount Rate Assumptions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					857
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Americas [Member] | Accounting Standards Update 2018-12 | Other Segments | Reclassification of Claims and Benefits payable
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[4]				17
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					239
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Americas [Member] | Accounting Standards Update 2018-12 | Other Segments | Accumulated Other Comprehensive Income Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[5]				(28)
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					(45)
Deferred policy acquisition costs	[5]				114
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Canada Segment Reporting Information [Member] | Accounting Standards Update 2018-12 | Other Segments | Retained Earnings Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[3]				20
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Canada Segment Reporting Information [Member] | Accounting Standards Update 2018-12 | Other Segments | Effect Of Changes In Discount Rate Assumptions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					9
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Canada Segment Reporting Information [Member] | Accounting Standards Update 2018-12 | Other Segments | Reclassification of Claims and Benefits payable
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[4]				4
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Canada Segment Reporting Information [Member] | Accounting Standards Update 2018-12 | Other Segments | Accumulated Other Comprehensive Income Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[5]				0
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Deferred policy acquisition costs	[5]				0
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | EMEA [Member] | Accounting Standards Update 2018-12 | Other Segments | Retained Earnings Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[3]				256
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | EMEA [Member] | Accounting Standards Update 2018-12 | Other Segments | Effect Of Changes In Discount Rate Assumptions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					1,011
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | EMEA [Member] | Accounting Standards Update 2018-12 | Other Segments | Reclassification of Claims and Benefits payable
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[4]				67
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | EMEA [Member] | Accounting Standards Update 2018-12 | Other Segments | Accumulated Other Comprehensive Income Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[5]				0
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Deferred policy acquisition costs	[5]				0
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Asia Pacific [Member] | Accounting Standards Update 2018-12 | Other Segments | Retained Earnings Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[3]				8
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Asia Pacific [Member] | Accounting Standards Update 2018-12 | Other Segments | Effect Of Changes In Discount Rate Assumptions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits					3
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Asia Pacific [Member] | Accounting Standards Update 2018-12 | Other Segments | Reclassification of Claims and Benefits payable
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[4]				2
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Insurance, Other [Member] | Revision of Prior Period, Change in Accounting Principle, Adjustment | Asia Pacific [Member] | Accounting Standards Update 2018-12 | Other Segments | Accumulated Other Comprehensive Income Member
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Future policy benefits	[5]				0
Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change					0
Deferred policy acquisition costs	[5]				$ 0

[1] Includes adjustments for capping the net premium ratio at 100% and eliminating negative reserves on certain issue year cohorts.

[2] Amount includes certain reclassifications to conform with the revised presentation upon adoption of ASU 2018-12, such as reclassifying claims and benefits payable on long-duration contracts to liability for future policy benefits.

[3] Includes adjustments for capping the net premium ratio at 100% and eliminating negative reserves on certain issue year cohorts.

[4] Amount includes certain reclassifications to conform with the revised presentation upon adoption of ASU 2018-12, such as reclassifying claims and benefits payable on long-duration contracts to liability for future policy benefits.

[5] Adjustment to remove amounts associated with unrealized gains and losses previously recorded in AOCI (i.e., “shadow adjustments”).