Future Contract Benefits - Summary of Changes in Present Values of LFPB (UL and Other) (Details) - UL and Other - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Present Value of Expected LFPB
Balance as of beginning-of-year	$ 15,000	$ 14,818
Balance as of beginning-of-year, excluding shadow balance in AOCI	17,222	15,723
Effect of changes in cash flow assumptions		244	$ 173
Effect of actual variances from expected experience		289	$ (71)
Adjusted balance as of beginning-of-year	17,755	15,825
Interest accrual	863	775
Net assessments collected	1,168	1,210
Benefit payments	(1,051)	(588)
Balance as of end-of-year, excluding shadow balance in AOCI	18,735	17,222
Balance as of end-of-period	16,062	15,000
Less: reinsurance recoverables	5,211	4,708
Net balance as of end-of-period, net of reinsurance	$ 10,851	$ 10,292
Weighted-average duration of future policyholder benefit liability	16 years	17 years
Cumulative Effect, Period of Adoption, Adjustment
Present Value of Expected LFPB
Balance as of beginning-of-year	$ (2,222)	$ (905)
Balance as of end-of-period	$ (2,673)	$ (2,222)