Reserve for Future Policy Benefits and Contractholder Funds - Schedule of balances of and changes in liability for future policy benefits (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 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			$ (12)	$ 0
Effect of actual variances from expected experience			(7)	(41)
Adjusted beginning balance			1,776	1,778
Issuances	277	248
Interest accrual	30	28
Net premiums collected	(211)	(220)
Lapses and withdrawals	0	0
Ending balance at original discount rate	1,872	1,834
Effect of changes in discount rate assumptions	(75)	(25)
Ending balance	1,797	1,809
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			(12)	0
Effect of actual variances from expected experience			(10)	(70)
Total adjustments			2,828	2,867
Issuances	274	247
Interest accrual	59	48
Benefit payments	(225)	(207)
Lapses and withdrawals	0	0
Ending balance at original discount rate	2,936	2,955
Effect of changes in discount rate assumptions	(71)	39
Ending balance	2,865	2,994
Net reserve for future policy benefits	1,068	1,185
Less: reinsurance recoverables	86	129
Net reserve for future policy benefits, after reinsurance recoverables	982	1,056
Reserves related to short-duration contracts	271	281
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			(26)	(61)
Adjusted beginning balance			1,523	1,543
Issuances	259	243
Interest accrual	25	24
Net premiums collected	(186)	(199)
Lapses and withdrawals	0	0
Ending balance at original discount rate	1,621	1,611
Effect of changes in discount rate assumptions	(68)	(29)
Ending balance	1,553	1,582
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			(30)	(63)
Total adjustments			2,286	2,363
Issuances	256	242
Interest accrual	47	37
Benefit payments	(199)	(218)
Lapses and withdrawals	0	0
Ending balance at original discount rate	2,390	2,424
Effect of changes in discount rate assumptions	(64)	9
Ending balance	2,326	2,433
Net reserve for future policy benefits	773	851
Less: reinsurance recoverables	84	127
Net reserve for future policy benefits, after reinsurance recoverables	689	724
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			(12)	0
Effect of actual variances from expected experience			19	20
Adjusted beginning balance			253	235
Issuances	18	5
Interest accrual	5	4
Net premiums collected	(25)	(21)
Lapses and withdrawals	0	0
Ending balance at original discount rate	251	223
Effect of changes in discount rate assumptions	(7)	4
Ending balance	244	227
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			(12)	0
Effect of actual variances from expected experience			20	(7)
Total adjustments			$ 542	$ 504
Issuances	18	5
Interest accrual	12	11
Benefit payments	(26)	11
Lapses and withdrawals	0	0
Ending balance at original discount rate	546	531
Effect of changes in discount rate assumptions	(7)	30
Ending balance	539	561
Net reserve for future policy benefits	295	334
Less: reinsurance recoverables	2	2
Net reserve for future policy benefits, after reinsurance recoverables	$ 293	$ 332