MRBs (Reconciles of MRBs Assets and Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Market Risk Benefit [Line Items]
Market risk benefit assets	$ 4,108	$ 2,807
Market risk benefit liabilities	1,385	2,078
Net (Asset) Liability	(2,723)	(729)
Fixed Annuities [Member]
Market Risk Benefit [Line Items]
Market risk benefit assets	105	117
Market risk benefit liabilities	88	72
Net (Asset) Liability	(17)	(45)	$ 114
Retirement Plan Services Segment [Member]
Market Risk Benefit [Line Items]
Market risk benefit assets	37	24
Market risk benefit liabilities	4	2
Net (Asset) Liability	(33)	(22)	(1)
Variable Annuities [Member]
Market Risk Benefit [Line Items]
Market risk benefit assets	3,966	2,666
Market risk benefit liabilities	1,293	2,004
Net (Asset) Liability	$ (2,673)	$ (662)	$ 2,398