Future Contract Benefits - Summary of Changes in Present Values of Expected Net Premiums and LFPB (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Present Value of Expected Future Policy Benefits
Net balance as of end-of-period	$ 41,053		$ 39,807
Payout Annuities
Present Value of Expected Net Premiums
Balance as of beginning-of-year	0	$ 0
Beginning balance at original discount rate	0	0
Effect of actual variances from expected experience			0	$ 0
Adjusted balance as of beginning-of-year			0	0
Issuances	0	0
Interest accrual	0	0
Net premiums collected	0	0
Flooring impact of LFPB	0	0
Ending balance at original discount rate	0	0
Effect of cumulative changes in discount rate assumptions	0	0
Balance as of end-of-period	0	0
Present Value of Expected Future Policy Benefits
Balance as of beginning-of-year	2,009	2,085
Beginning balance at original discount rate	2,260	2,272
Effect of actual variances from expected experience			(6)	3
Adjusted balance as of beginning-of-year			2,254	2,275
Issuances	46	39
Interest accrual	44	43
Benefit payments	(97)	(98)
Ending balance at original discount rate	2,247	2,259
Effect of cumulative changes in discount rate assumptions	(208)	(257)
Balance as of end-of-period	2,039	2,002
Net balance as of end-of-period	2,039	2,002	2,009
Less: Reinsurance recoverables	1,467	1,516
Net balance as of end-of-period, net of reinsurance	$ 572	$ 486
Weighted-average duration of future policyholder benefit liability	9 years	9 years
Deferred profit liability	$ 70	$ 61
Payout Annuities | Cumulative Effect, Period of Adoption, Adjustment
Present Value of Expected Net Premiums
Balance as of beginning-of-year	0	0
Present Value of Expected Future Policy Benefits
Balance as of beginning-of-year	(251)	(187)
Traditional Life
Present Value of Expected Net Premiums
Balance as of beginning-of-year	5,873	6,200
Beginning balance at original discount rate	6,148	6,348
Effect of actual variances from expected experience			(62)	(40)
Adjusted balance as of beginning-of-year			6,086	6,308
Issuances	141	206
Interest accrual	124	125
Net premiums collected	(384)	(403)
Flooring impact of LFPB	(7)	2
Ending balance at original discount rate	5,960	6,238
Effect of cumulative changes in discount rate assumptions	(154)	(321)
Balance as of end-of-period	5,806	5,917
Present Value of Expected Future Policy Benefits
Balance as of beginning-of-year	9,647	10,041
Beginning balance at original discount rate	10,085	10,230
Effect of actual variances from expected experience			(82)	(45)
Adjusted balance as of beginning-of-year			10,003	$ 10,185
Issuances	141	206
Interest accrual	199	199
Benefit payments	(430)	(384)
Ending balance at original discount rate	9,913	10,206
Effect of cumulative changes in discount rate assumptions	(240)	(506)
Balance as of end-of-period	9,673	9,700
Net balance as of end-of-period	3,867	3,783	$ 3,774
Less: Reinsurance recoverables	345	403
Net balance as of end-of-period, net of reinsurance	$ 3,522	$ 3,380
Weighted-average duration of future policyholder benefit liability	8 years	9 years
Impact on net premiums, mortality	$ 19	$ 43
Impact on net premiums, policyholder behavior	43	3
Effect on liability based on mortality	25	62
Decrease in the liability based on policyholder behavior	57	17
Traditional Life | Cumulative Effect, Period of Adoption, Adjustment
Present Value of Expected Net Premiums
Balance as of beginning-of-year	(275)	(148)
Present Value of Expected Future Policy Benefits
Balance as of beginning-of-year	$ (438)	$ (189)