Future Contract Benefits - Summary of Changes in Present Values of Expected Net Premiums and LFPB (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025	Dec. 31, 2024
Present Value of Expected Future Policy Benefits
Net balance as of end-of-period	$ 41,957		$ 42,360
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	2,036	2,008
Beginning balance of original discount rate	2,218	2,259
Effect of actual variances from expected experience			(3)	(1)
Effect of cumulative changes in discount rate assumptions	(210)	(221)
Adjusted balance as of beginning-of-year			2,215	2,258
Issuances	18	22
Interest accrual	22	22
Benefit payments	(55)	(49)
Ending balance at original discount rate	2,200	2,253
Balance as of end-of-period	1,990	2,032
Net balance as of end-of-period	1,990	2,032	2,036
Less: Reinsurance recoverables	1,407	1,491
Net balance as of end-of-period, net of reinsurance	$ 583	$ 541
Weighted-average duration of future policyholder benefit liability (years)	8 years	9 years
Deferred profit liability	$ 94	$ 65	92	62
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	(182)	(251)
Traditional Life
Present Value of Expected Net Premiums
Balance as of beginning-of-year	5,286	5,751
Beginning balance at original discount rate	5,378	6,028
Effect of actual variances from expected experience			(6)	(18)
Adjusted balance as of beginning-of-year			5,372	6,010
Issuances	72	64
Interest accrual	56	61
Net premiums collected	(174)	(189)
Flooring impact of LFPB	(11)	(3)
Ending balance at original discount rate	5,315	5,943
Effect of cumulative changes in discount rate assumptions	(158)	(197)
Balance as of end-of-period	5,157	5,746
Present Value of Expected Future Policy Benefits
Balance as of beginning-of-year	8,807	9,255
Beginning balance of original discount rate	8,961	9,701
Effect of actual variances from expected experience			(29)	(13)
Effect of cumulative changes in discount rate assumptions	(270)	(314)
Adjusted balance as of beginning-of-year			8,932	9,688
Issuances	72	64
Interest accrual	89	95
Benefit payments	(187)	(221)
Ending balance at original discount rate	8,906	9,626
Balance as of end-of-period	8,636	9,312
Net balance as of end-of-period	3,479	3,566	3,521
Less: Reinsurance recoverables	170	210
Net balance as of end-of-period, net of reinsurance	$ 3,309	$ 3,356
Weighted-average duration of future policyholder benefit liability (years)	8 years	9 years
Impact on future policy benefits, mortality	$ 21
Impact on future policy benefits, policyholder behavior	8
Traditional Life | Cumulative effect from adoption of new accounting standards
Present Value of Expected Net Premiums
Balance as of beginning-of-year	(92)	$ (277)
Present Value of Expected Future Policy Benefits
Balance as of beginning-of-year	(154)	(446)
Group Protection
Present Value of Expected Net Premiums
Effect of cumulative changes in discount rate assumptions			(363)	(550)
Present Value of Expected Future Policy Benefits
Balance as of beginning-of-year	5,836	5,628
Beginning balance of original discount rate	6,199	6,178
Effect of actual variances from expected experience			(47)	(72)
Effect of cumulative changes in discount rate assumptions	(411)	(475)
Adjusted balance as of beginning-of-year			6,152	$ 6,106
Issuances	377	402
Interest accrual	55	50
Benefit payments	(380)	(371)
Ending balance at original discount rate	6,204	6,187
Balance as of end-of-period	5,793	5,712
Net balance as of end-of-period	5,793		$ 5,836
Less: Reinsurance recoverables	3,733	3,600
Net balance as of end-of-period, net of reinsurance	$ 2,060	$ 2,112
Weighted-average duration of future policyholder benefit liability (years)	5 years	5 years