Policyholder Account Balances, Future Policy Benefits and Claims - Balance of and Changes in Policyholder Account Balances (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Policyholder Account Balance [Roll Forward]
Beginning balance	$ 27,947	$ 24,986
Contract deposits	1,143	3,884
Policy charges	(102)	(401)
Surrenders and other benefits	(596)	(2,382)
Net transfer from (to) separate account liabilities	(26)	(132)
Variable account index-linked adjustments	704	1,403
Interest credited	159	589
Ending balance	29,229	27,947
Variable Annuities
Policyholder Account Balance [Roll Forward]
Beginning balance	4,173	4,752
Contract deposits	10	73
Policy charges	(3)	(10)
Surrenders and other benefits	(181)	(759)
Net transfer from (to) separate account liabilities	(7)	(25)
Variable account index-linked adjustments	0	0
Interest credited	32	142
Ending balance	$ 4,024	$ 4,173
Weighted-average crediting rate	3.30%	3.30%
Cash surrender value	$ 3,999	$ 4,146
Structured Variable Annuities
Policyholder Account Balance [Roll Forward]
Beginning balance	10,742	6,410
Contract deposits	955	3,084
Policy charges	0	0
Surrenders and other benefits	(74)	(156)
Net transfer from (to) separate account liabilities	0	0
Variable account index-linked adjustments	704	1,403
Interest credited	0	1
Ending balance	$ 12,327	$ 10,742
Weighted-average crediting rate	1.80%	1.80%
Cash surrender value	$ 11,656	$ 10,129
Fixed Annuities
Policyholder Account Balance [Roll Forward]
Beginning balance	5,982	6,799
Contract deposits	11	47
Policy charges	0	0
Surrenders and other benefits	(244)	(1,086)
Net transfer from (to) separate account liabilities	0	0
Variable account index-linked adjustments	0	0
Interest credited	52	222
Ending balance	$ 5,801	$ 5,982
Weighted-average crediting rate	3.60%	3.60%
Cash surrender value	$ 5,794	$ 5,974
Fixed Indexed Annuities
Policyholder Account Balance [Roll Forward]
Beginning balance	307	312
Contract deposits	0	0
Policy charges	0	0
Surrenders and other benefits	(4)	(10)
Net transfer from (to) separate account liabilities	0	0
Variable account index-linked adjustments	0	0
Interest credited	4	5
Ending balance	$ 307	$ 307
Weighted-average crediting rate	2.00%	2.00%
Cash surrender value	$ 278	$ 278
Non-Life Contingent Payout Annuities
Policyholder Account Balance [Roll Forward]
Beginning balance	444	471
Contract deposits	30	91
Policy charges	0	0
Surrenders and other benefits	(28)	(127)
Net transfer from (to) separate account liabilities	0	0
Variable account index-linked adjustments	0	0
Interest credited	3	9
Ending balance	449	444
Universal Life Insurance
Policyholder Account Balance [Roll Forward]
Beginning balance	1,474	1,544
Contract deposits	29	123
Policy charges	(44)	(176)
Surrenders and other benefits	(13)	(69)
Net transfer from (to) separate account liabilities	0	0
Variable account index-linked adjustments	0	0
Interest credited	12	52
Ending balance	$ 1,458	$ 1,474
Weighted-average crediting rate	3.60%	3.60%
Net amount at risk	$ 8,626	$ 8,740
Cash surrender value	1,318	1,330
Variable Universal Life Insurance
Policyholder Account Balance [Roll Forward]
Beginning balance	1,569	1,520
Contract deposits	62	272
Policy charges	(23)	(94)
Surrenders and other benefits	(21)	(78)
Net transfer from (to) separate account liabilities	(19)	(107)
Variable account index-linked adjustments	0	0
Interest credited	15	56
Ending balance	$ 1,583	$ 1,569
Weighted-average crediting rate	3.90%	3.90%
Net amount at risk	$ 56,939	$ 57,291
Cash surrender value	1,072	1,065
Indexed Universal Life Insurance
Policyholder Account Balance [Roll Forward]
Beginning balance	2,755	2,654
Contract deposits	46	193
Policy charges	(32)	(121)
Surrenders and other benefits	(17)	(53)
Net transfer from (to) separate account liabilities	0	0
Variable account index-linked adjustments	0	0
Interest credited	37	82
Ending balance	$ 2,789	$ 2,755
Weighted-average crediting rate	2.00%	2.00%
Net amount at risk	$ 14,215	$ 14,407
Cash surrender value	2,315	2,271
Other Life Insurance
Policyholder Account Balance [Roll Forward]
Beginning balance	501	524
Contract deposits	0	1
Policy charges	0	0
Surrenders and other benefits	(14)	(44)
Net transfer from (to) separate account liabilities	0	0
Variable account index-linked adjustments	0	0
Interest credited	4	20
Ending balance	$ 491	$ 501
Weighted-average crediting rate	4.00%	4.00%
Net amount at risk	$ 139	$ 141
Cash surrender value	$ 319	$ 326