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	$ 41,304		$ 40,002
Actual effect on liability, based on policyholder behavior		$ 54
Actual effect on liability, based on mortality		39
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	2,008	2,084
Beginning balance of original discount rate	2,259	2,271
Effect of actual variances from expected experience			(6)	3
Adjusted balance as of beginning-of-year			2,253	2,274
Issuances	47	39
Interest accrual	44	43
Benefit payments	(97)	(98)
Ending balance at original discount rate	2,247	2,258
Effect of cumulative changes in discount rate assumptions	(208)	(257)
Balance as of end-of-period	2,039	2,001
Net balance as of end-of-period	2,039	2,001	2,008
Less: Reinsurance recoverables	1,481	1,527
Net balance as of end-of-period, net of reinsurance	$ 558	$ 474
Weighted-average duration of future policyholder benefit liability (years)	9 years	9 years
Deferred profit liability	$ 70	$ 61
Payout Annuities | Cumulative effect from adoption of new accounting standards
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	5,751	6,084
Beginning balance at original discount rate	6,028	6,236
Effect of actual variances from expected experience			(32)	(10)
Adjusted balance as of beginning-of-year			5,996	6,226
Issuances	141	206
Interest accrual	121	122
Net premiums collected	(376)	(396)
Flooring impact of LFPB	(4)	2
Ending balance at original discount rate	5,878	6,160
Effect of cumulative changes in discount rate assumptions	(156)	(322)
Balance as of end-of-period	5,722	5,838
Present Value of Expected Future Policy Benefits
Balance as of beginning-of-year	9,255	9,637
Beginning balance of original discount rate	9,701	9,839
Effect of actual variances from expected experience			(39)	(15)
Adjusted balance as of beginning-of-year			9,662	9,824
Issuances	141	206
Interest accrual	190	190
Benefit payments	(404)	(357)
Ending balance at original discount rate	9,589	9,863
Effect of cumulative changes in discount rate assumptions	(250)	(511)
Balance as of end-of-period	9,339	9,352
Net balance as of end-of-period	3,617	3,514	3,504
Less: Reinsurance recoverables	212	232
Net balance as of end-of-period, net of reinsurance	$ 3,405	$ 3,282
Weighted-average duration of future policyholder benefit liability (years)	9 years	10 years
Expected effect on liability, based on policyholder behavior	$ 19	$ 38
Expected effect on liability, based on mortality	13	(28)
Actual effect on liability, based on policyholder behavior	23
Actual effect on liability, based on mortality	(16)
Traditional Life | Cumulative effect from adoption of new accounting standards
Present Value of Expected Net Premiums
Balance as of beginning-of-year	(277)	(152)
Present Value of Expected Future Policy Benefits
Balance as of beginning-of-year	(446)	(202)
Group Protection
Present Value of Expected Net Premiums
Effect of cumulative changes in discount rate assumptions			(550)	(490)
Present Value of Expected Future Policy Benefits
Balance as of beginning-of-year	5,628	5,689
Beginning balance of original discount rate	6,178	6,179
Effect of actual variances from expected experience			(178)	(191)
Adjusted balance as of beginning-of-year			6,000	$ 5,988
Issuances	808	838
Interest accrual	100	93
Benefit payments	(724)	(757)
Ending balance at original discount rate	6,184	6,162
Effect of cumulative changes in discount rate assumptions	(425)	(593)
Balance as of end-of-period	5,759	5,569
Net balance as of end-of-period	5,759		$ 5,628
Less: Reinsurance recoverables	3,439	4,284
Net balance as of end-of-period, net of reinsurance	$ 2,320	$ 1,285
Weighted-average duration of future policyholder benefit liability (years)	5 years	5 years