Future Contract Benefits - Summary of Gross Premiums and Interest Accretion (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Payout Annuities
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	$ 34	$ 25	$ 51	$ 48
Interest accretion	22	22	44	44
Traditional Life
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	317	298	607	597
Interest accretion	$ 34	$ 35	$ 67	$ 69