Future Contract Benefit - Summary of Gross Premiums and Interest Accretion (UL and Other) (Details) - UL and Other - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Liability for Future Policy Benefit, Activity [Line Items]
Gross assessments	$ 787	$ 678	$ 1,487	$ 1,444
Interest accretion	$ 233	$ 212	$ 461	$ 421