Future Contract Benefits - Summary of Changes in Present Values of LFPB (UL and Other) (Details) - UL and Other - 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
Balance as of beginning-of-year	$ 18,597	$ 16,663
Effect of cumulative changes in discount rate assumptions	(1,418)	(1,231)	$ (1,086)	$ (1,515)
Balance as of beginning-of-year, excluding shadow balance in AOCI	19,683	18,178
Effect of actual variances from expected experience			$ 63	$ 22
Adjusted balance as of beginning-of-year	19,746	18,200
Interest accrual	244	223
Net assessments collected	338	341
Benefit payments	(304)	(200)
Balance as of end-of-year, excluding shadow balance in AOCI	20,024	18,564
Balance as of end-of-period	18,606	17,333
Less: Reinsurance recoverables	12,033	11,026
Net balance as of end-of-period, net of reinsurance	$ 6,573	$ 6,307
Weighted-average duration of future policyholder benefit liability (years)	16 years	16 years
Actual effect on liability, based on mortality	$ 56	$ 0
Effect of actual variances from expected experience, net of reinsurance	$ 34	$ 6