Future Contract Benefits - Summary of Gross Premiums and Interest Accretion (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Payout Annuities
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	$ 24	$ 44	$ 45	$ 71
Interest accretion	22	21	43	43
Traditional Life
Liability for Future Policy Benefit, Activity [Line Items]
Gross premiums	301	297	599	592
Interest accretion	$ 34	$ 32	$ 67	$ 63