Reserve for Future Policy Benefits and Contractholder Funds - Schedule of balances of and changes in liability for future policy benefits (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Present value of expected net premiums
Beginning balance	$ 1,702	$ 2,039
Beginning balance at original discount rate	1,795	1,819
Effect of changes in cash flow assumptions			$ 0	$ 0
Effect of actual variances from expected experience			(37)	(29)
Adjusted beginning balance			1,758	1,790
Issuances	216	177
Interest accrual	15	14
Net premiums collected	(107)	(114)
Lapses and withdrawals	0	0
Ending balance at original discount rate	1,882	1,867
Effect of changes in discount rate assumptions	(67)	85
Ending balance	1,815	1,952
Present value of expected future policy benefits
Beginning balance	2,753	3,469
Beginning balance at original discount rate	2,850	2,937
Effect of changes in cash flow assumptions			0	0
Effect of actual variances from expected experience			(43)	(34)
Total adjustments			2,807	2,903
Issuances	215	176
Interest accrual	25	24
Benefit payments	(111)	(118)
Lapses and withdrawals	0	0
Ending balance at original discount rate	2,936	2,985
Effect of changes in discount rate assumptions	(54)	269
Ending balance	2,882	3,254
Net reserve for future policy benefits	1,067	1,302
Less: reinsurance recoverables	78	141
Net reserve for future policy benefits, after reinsurance recoverables	989	1,161
Reserves related to short-duration contracts	271	264
Accident and health insurance
Present value of expected net premiums
Beginning balance	1,464	1,785
Beginning balance at original discount rate	1,549	1,604
Effect of changes in cash flow assumptions			0	0
Effect of actual variances from expected experience			(42)	(49)
Adjusted beginning balance			1,507	1,555
Issuances	199	173
Interest accrual	12	12
Net premiums collected	(95)	(103)
Lapses and withdrawals	0	0
Ending balance at original discount rate	1,623	1,637
Effect of changes in discount rate assumptions	(62)	65
Ending balance	1,561	1,702
Present value of expected future policy benefits
Beginning balance	2,229	2,796
Beginning balance at original discount rate	2,316	2,426
Effect of changes in cash flow assumptions			0	0
Effect of actual variances from expected experience			(47)	(53)
Total adjustments			2,269	2,373
Issuances	199	172
Interest accrual	19	19
Benefit payments	(99)	(110)
Lapses and withdrawals	0	0
Ending balance at original discount rate	2,388	2,454
Effect of changes in discount rate assumptions	(53)	175
Ending balance	2,335	2,629
Net reserve for future policy benefits	774	927
Less: reinsurance recoverables	76	139
Net reserve for future policy benefits, after reinsurance recoverables	698	788
Traditional life
Present value of expected net premiums
Beginning balance	238	254
Beginning balance at original discount rate	246	215
Effect of changes in cash flow assumptions			0	0
Effect of actual variances from expected experience			5	20
Adjusted beginning balance			251	235
Issuances	17	4
Interest accrual	3	2
Net premiums collected	(12)	(11)
Lapses and withdrawals	0	0
Ending balance at original discount rate	259	230
Effect of changes in discount rate assumptions	(5)	20
Ending balance	254	250
Present value of expected future policy benefits
Beginning balance	524	673
Beginning balance at original discount rate	534	511
Effect of changes in cash flow assumptions			0	0
Effect of actual variances from expected experience			4	19
Total adjustments			$ 538	$ 530
Issuances	16	4
Interest accrual	6	5
Benefit payments	(12)	(8)
Lapses and withdrawals	0	0
Ending balance at original discount rate	548	531
Effect of changes in discount rate assumptions	(1)	94
Ending balance	547	625
Net reserve for future policy benefits	293	375
Less: reinsurance recoverables	2	2
Net reserve for future policy benefits, after reinsurance recoverables	$ 291	$ 373