MRBs - Reconciles of MRBs Assets and Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Market Risk Benefit [Line Items]
Assets	$ 4,878	$ 3,894
Liabilities	1,266	1,716
Net (Assets) Liabilities	(3,612)	(2,178)
Variable Annuities
Market Risk Benefit [Line Items]
Assets	4,743	3,763
Liabilities	1,139	1,583
Net (Assets) Liabilities	(3,604)	(2,180)	$ (1,412)	$ (662)
Fixed Annuities
Market Risk Benefit [Line Items]
Assets	96	96
Liabilities	123	128
Net (Assets) Liabilities	27	32	(31)	(45)
Retirement Plan Services
Market Risk Benefit [Line Items]
Assets	39	35
Liabilities	4	5
Net (Assets) Liabilities	$ (35)	$ (30)	$ (26)	$ (22)