Future Contract Benefits - Summary of Changes in Present Values of LFPB (UL and Other) (Details) - UL and Other - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2022
Present Value of Expected LFPB
Balance as of beginning-of-year	$ 15,752	$ 14,777
Effect of cumulative changes in discount rate assumptions	(2,032)	(1,769)	$ (853)	$ (905)
Balance as of beginning-of-year, excluding shadow balance in AOCI	16,605	15,682
Effect of actual variances from expected experience			$ 136	$ 6
Adjusted balance as of beginning-of-year	16,741	15,688
Interest accrual	410	377
Net assessments collected	638	190
Benefit payments	(521)	(360)
Balance as of end-of-year, excluding shadow balance in AOCI	17,268	15,895
Balance as of end-of-period	15,236	14,126
Less: reinsurance recoverables (2)	10,040	2,041
Net balance as of end-of-period, net of reinsurance	$ 5,196	$ 12,085
Weighted-average duration of future policyholder benefit liability (years)	16 years	18 years