Future Contract Benefit - Summary of Gross Premiums and Interest Accretion (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Payout Annuities
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	$ 23	$ 21
Interest accretion	22	22
Traditional Life
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	314	314
Interest accretion	$ 37	$ 37