Reserve for Future Policy Benefits and Contractholder Funds - Schedule of Rollforward of Reserve for Future Policy Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Present value of expected net premiums
Beginning balance	$ 1,702	$ 2,039	$ 1,779
Beginning balance at original discount rate	1,795	1,819	1,461
Effect of changes in cash flow assumptions		22	0	$ 0
Effect of actual variances from expected experience		(8)	(101)	(37)
Adjusted beginning balance		1,809	1,718	1,424
Issuances	590	405	703
Interest accrual	80	52	59
Net premiums collected	(412)	(380)	(367)
Ending balance at original discount rate	2,067	1,795	1,819
Effect of changes in discount rate assumptions	(54)	(93)	220
Ending balance	2,013	1,702	2,039
Present value of expected future policy benefits
Beginning balance	2,753	3,469	3,206
Beginning balance at original discount rate	2,850	2,937	2,496
Effect of changes in cash flow assumptions		51	(44)	(2)
Effect of actual variances from expected experience		(32)	(92)	(1)
Adjusted beginning balance		2,869	2,801	2,493
Issuances (1)	588	402	758
Interest accrual	128	88	101
Benefit payments	(434)	(441)	(415)
Ending balance at original discount rate	3,151	2,850	2,937
Effect of changes in discount rate assumptions	(41)	(97)	532
Ending balance	3,110	2,753	3,469
Net reserve for future policy benefits	1,097	1,051	1,430
Less: reinsurance recoverables	83	77	151
Net reserve for future policy benefits, after reinsurance recoverables	1,014	974	1,279
Reserves related to short-duration contracts	250	271	265
Accident and health
Present value of expected net premiums
Beginning balance	1,464	1,785	1,575
Beginning balance at original discount rate	1,549	1,604	1,307
Effect of changes in cash flow assumptions		(12)	0	0
Effect of actual variances from expected experience		(10)	(137)	(32)
Adjusted beginning balance		1,527	1,467	1,275
Issuances	501	371	620
Interest accrual	69	48	52
Net premiums collected	(360)	(337)	(343)
Ending balance at original discount rate	1,737	1,549	1,604
Effect of changes in discount rate assumptions	(49)	(85)	181
Ending balance	1,688	1,464	1,785
Present value of expected future policy benefits
Beginning balance	2,229	2,796	2,577
Beginning balance at original discount rate	2,316	2,426	2,070
Effect of changes in cash flow assumptions		21	(44)	(2)
Effect of actual variances from expected experience		(33)	(116)	(5)
Adjusted beginning balance		2,304	2,266	2,063
Issuances (1)	486	360	664
Interest accrual	103	76	80
Benefit payments	(398)	(386)	(381)
Ending balance at original discount rate	2,495	2,316	2,426
Effect of changes in discount rate assumptions	(42)	(87)	370
Ending balance	2,453	2,229	2,796
Net reserve for future policy benefits	765	765	1,011
Less: reinsurance recoverables	81	76	149
Net reserve for future policy benefits, after reinsurance recoverables	684	689	862
Traditional life
Present value of expected net premiums
Beginning balance	238	254	204
Beginning balance at original discount rate	246	215	154
Effect of changes in cash flow assumptions		34	0	0
Effect of actual variances from expected experience		2	36	(5)
Adjusted beginning balance		282	251	149
Issuances	89	34	83
Interest accrual	11	4	7
Net premiums collected	(52)	(43)	(24)
Ending balance at original discount rate	330	246	215
Effect of changes in discount rate assumptions	(5)	(8)	39
Ending balance	325	238	254
Present value of expected future policy benefits
Beginning balance	524	673	629
Beginning balance at original discount rate	534	511	426
Effect of changes in cash flow assumptions		30	0	0
Effect of actual variances from expected experience		1	24	4
Adjusted beginning balance		565	535	$ 430
Issuances (1)	102	42	94
Interest accrual	25	12	21
Benefit payments	(36)	(55)	(34)
Ending balance at original discount rate	656	534	511
Effect of changes in discount rate assumptions	1	(10)	162
Ending balance	657	524	673
Net reserve for future policy benefits	332	286	419
Less: reinsurance recoverables	2	1	2
Net reserve for future policy benefits, after reinsurance recoverables	$ 330	$ 285	$ 417