Reserves for Insurance Losses and Loss Adjustment Expenses (Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Short-Duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Reserves for insurance losses and loss adjustment expenses, net of reinsurance	$ 71	$ 44	$ 39
Total reinsurance recoverable on unpaid claims	66	72	81	$ 90
Unallocated loss adjustment expenses	3	3	2
Total gross reserves for insurance losses and loss adjustment expenses	$ 140	$ 119	$ 122	$ 129