Reserves for Insurance Losses and Loss Adjustment Expenses (Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net [Abstract]
Reserves for insurance losses and allocated loss adjustment expenses, net of reinsurance	$ 39	$ 37	$ 32
Total reinsurance recoverable on unpaid claims	81	90	88	$ 96
Unallocated loss adjustment expenses	2	2	2
Total gross reserves for insurance losses and loss adjustment expenses	$ 122	$ 129	$ 122	$ 134