Liability for Future Policy Benefit (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Net liability for future policy benefits:
Net life policy reserves	$ 3,013		$ 3,068
Life policy reserves:
Net liability for future policy benefits:
Net life policy reserves	1,571		1,597
Term Life Insurance | Life policy reserves:
Present value of expected net premiums:
Balance, beginning of period	1,700	$ 1,643
Beginning balance at original discount rate	1,712	1,708
Effect of changes in cash flow assumptions	0	0
Effect of changes in cash flow assumptions	(9)	(3)
Adjusted beginning of period balance	1,703	1,705
Issuances	35	38
Interest accrual	18	18
Net premiums collected	(46)	(46)
Ending balance at original discount rate	1,710	1,715
Effect of changes in discount rate assumptions	(50)	(16)
Balance, end of period	1,660	1,699
Present value of expected future policy benefits:
Balance, beginning of period	2,751	2,584
Effect of changes in cash flow assumptions	2,765	2,692
Effect of changes in cash flow assumptions	0	0
Effect of changes in cash flow assumptions	(14)	(2)
Adjusted beginning of period balance	2,751	2,690
Issuances	35	38
Interest accrual	31	30
Benefits paid	(37)	(46)
Ending balance at original discount rate	2,780	2,712
Effect of changes in discount rate assumptions	(82)	(21)
Balance, end of period	2,698	2,691
Net liability for future policy benefits:
Present value of expected future policy benefits less expected net premiums	1,038	992
Impact of flooring at cohort level	16	19
Net life policy reserves	1,054	1,011	1,066
Less reinsurance recoverable at original discount rate	(100)	(96)
Less effect of discount rate assumption changes on reinsurance recoverable	(8)	(10)
Net life policy reserves, after reinsurance recoverable	$ 946	$ 905
Weighted-average duration of the net life policy reserves in years	11 years	12 years
Whole Life Insurance | Life policy reserves:
Present value of expected net premiums:
Balance, beginning of period	$ 223	$ 208
Beginning balance at original discount rate	225	217
Effect of changes in cash flow assumptions	0	0
Effect of changes in cash flow assumptions	0	1
Adjusted beginning of period balance	225	218
Issuances	5	7
Interest accrual	2	2
Net premiums collected	(7)	(7)
Ending balance at original discount rate	225	220
Effect of changes in discount rate assumptions	(6)	(3)
Balance, end of period	219	217
Present value of expected future policy benefits:
Balance, beginning of period	657	614
Effect of changes in cash flow assumptions	628	607
Effect of changes in cash flow assumptions	0	0
Effect of changes in cash flow assumptions	0	1
Adjusted beginning of period balance	628	608
Issuances	5	6
Interest accrual	8	8
Benefits paid	(8)	(8)
Ending balance at original discount rate	633	614
Effect of changes in discount rate assumptions	4	30
Balance, end of period	637	644
Net liability for future policy benefits:
Present value of expected future policy benefits less expected net premiums	418	427
Impact of flooring at cohort level	0	0
Net life policy reserves	418	427	$ 434
Less reinsurance recoverable at original discount rate	(24)	(25)
Less effect of discount rate assumption changes on reinsurance recoverable	(4)	(6)
Net life policy reserves, after reinsurance recoverable	$ 390	$ 396
Weighted-average duration of the net life policy reserves in years	16 years	16 years