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	$ 17,948	$ 16,062
Effect of cumulative changes in shadow balance in AOCI	(2,156)	(2,377)	$ (2,191)	$ (2,673)
Balance as of beginning-of-year, excluding shadow balance in AOCI	20,139	18,735
Effect of actual variances from expected experience			$ 63	$ 23
Adjusted balance as of beginning-of-year	20,202	18,758
Interest accrual	248	228
Net assessments collected	318	293
Benefit payments	(304)	(200)
Balance as of end-of-year, excluding shadow balance in AOCI	20,464	19,079
Balance as of end-of-period	18,308	16,702
Less: Reinsurance recoverables	5,582	5,316
Net balance as of end-of-period, net of reinsurance	$ 12,726	$ 11,386
Weighted-average duration of future policyholder benefit liability	16 years	16 years
Effect on liability based on mortality	$ 56
Effect of actual variances from expected experience, net of reinsurance	$ 33	$ 11