Future Contract Benefit - Summary of Gross Premiums and Interest Accretion (Group Protection) (Details) - Group Protection - 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 premiums	$ 926	$ 893	$ 1,859	$ 1,789
Interest accretion	$ 50	$ 45	$ 100	$ 93