Future Contract Benefit - Summary of Gross Premiums and Interest Accretion (Group Protection) (Details) - Group Protection - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	$ 3,563	$ 3,549	$ 3,393
Interest accretion	$ 181	$ 159	$ 141