Future Contract Benefits - Summary of Changes in Present Values of LFPB (UL and Other) (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
Actual effect on liability, based on mortality		$ 39
UL and Other
Present Value of Expected Future Policy Benefits
Balance as of beginning-of-year	$ 16,663	15,752
Effect of cumulative changes in discount rate assumptions	(1,273)	(2,032)	$ (1,515)	$ (853)
Balance as of beginning-of-year, excluding shadow balance in AOCI	18,178	16,605
Effect of actual variances from expected experience			$ 116	$ 136
Adjusted balance as of beginning-of-year	18,294	16,741
Interest accrual	452	410
Net assessments collected	681	638
Benefit payments	(532)	(521)
Balance as of end-of-year, excluding shadow balance in AOCI	18,895	17,268
Balance as of end-of-period	17,622	15,236
Less: Reinsurance recoverables	11,269	10,040
Net balance as of end-of-period, net of reinsurance	$ 6,353	$ 5,196
Weighted-average duration of future policyholder benefit liability (years)	16 years	16 years
Actual effect on liability, based on mortality	$ 116	$ 138
Effect of actual variances from expected experience, net of reinsurance	$ 33	$ 79