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, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Present value of expected net premiums
Beginning balance	$ 2,013	$ 1,702	$ 2,039
Beginning balance at original discount rate	2,067	1,795	1,819
Effect of changes in cash flow assumptions		(101)	22	$ 0
Effect of actual variances from expected experience		40	(8)	(101)
Adjusted beginning balance		2,006	1,809	1,718
Issuances	707	590	405
Interest accrual	106	80	52
Net premiums collected	(452)	(412)	(380)
Ending balance at original discount rate	2,367	2,067	1,795
Effect of changes in discount rate assumptions	(65)	(54)	(93)
Reclassified to liabilities held for sale	(1,584)	0	0
Ending balance	718	2,013	1,702
Present value of expected future policy benefits
Beginning balance	3,110	2,753	3,469
Beginning balance at original discount rate	3,151	2,850	2,937
Effect of changes in cash flow assumptions		(21)	51	(44)
Effect of actual variances from expected experience		(18)	(32)	(92)
Adjusted beginning balance		3,112	2,869	2,801
Issuances	692	588	402
Interest accrual	150	128	88
Benefit payments	(469)	(434)	(441)
Ending balance at original discount rate	3,485	3,151	2,850
Effect of changes in discount rate assumptions	(87)	(41)	(97)
Reclassified to liabilities held for sale	(2,628)	0	0
Ending balance	770	3,110	2,753
Net reserve for future policy benefits	52	1,097	1,051
Less: reinsurance recoverables	0	83	77
Net reserve for future policy benefits, after reinsurance recoverables	52	1,014	974
Reserves related to short-duration contracts	217	250	271
Accident and health
Present value of expected net premiums
Beginning balance	1,688	1,464	1,785
Beginning balance at original discount rate	1,737	1,549	1,604
Effect of changes in cash flow assumptions		(88)	(12)	0
Effect of actual variances from expected experience		34	(10)	(137)
Adjusted beginning balance		1,683	1,527	1,467
Issuances	624	501	371
Interest accrual	91	69	48
Net premiums collected	(385)	(360)	(337)
Ending balance at original discount rate	2,013	1,737	1,549
Effect of changes in discount rate assumptions	(54)	(49)	(85)
Reclassified to liabilities held for sale	(1,247)	0	0
Ending balance	712	1,688	1,464
Present value of expected future policy benefits
Beginning balance	2,453	2,229	2,796
Beginning balance at original discount rate	2,495	2,316	2,426
Effect of changes in cash flow assumptions		(11)	21	(44)
Effect of actual variances from expected experience		(17)	(33)	(116)
Adjusted beginning balance		2,467	2,304	2,266
Issuances	609	486	360
Interest accrual	119	103	76
Benefit payments	(437)	(398)	(386)
Ending balance at original discount rate	2,758	2,495	2,316
Effect of changes in discount rate assumptions	(58)	(42)	(87)
Reclassified to liabilities held for sale	(1,943)	0	0
Ending balance	757	2,453	2,229
Net reserve for future policy benefits	45	765	765
Less: reinsurance recoverables	0	81	76
Net reserve for future policy benefits, after reinsurance recoverables	45	684	689
Traditional life
Present value of expected net premiums
Beginning balance	325	238	254
Beginning balance at original discount rate	330	246	215
Effect of changes in cash flow assumptions		(13)	34	0
Effect of actual variances from expected experience		6	2	36
Adjusted beginning balance		323	282	251
Issuances	83	89	34
Interest accrual	15	11	4
Net premiums collected	(67)	(52)	(43)
Ending balance at original discount rate	354	330	246
Effect of changes in discount rate assumptions	(11)	(5)	(8)
Reclassified to liabilities held for sale	(337)	0	0
Ending balance	6	325	238
Present value of expected future policy benefits
Beginning balance	657	524	673
Beginning balance at original discount rate	656	534	511
Effect of changes in cash flow assumptions		(10)	30	0
Effect of actual variances from expected experience		(1)	1	24
Adjusted beginning balance		645	565	$ 535
Issuances	83	102	42
Interest accrual	31	25	12
Benefit payments	(32)	(36)	(55)
Ending balance at original discount rate	727	656	534
Effect of changes in discount rate assumptions	(29)	1	(10)
Reclassified to liabilities held for sale	(685)	0	0
Ending balance	13	657	524
Net reserve for future policy benefits	7	332	286
Less: reinsurance recoverables	0	2	1
Net reserve for future policy benefits, after reinsurance recoverables	$ 7	$ 330	$ 285