Reserves for Insurance Losses and Loss Adjustment Expenses (Rollforward of Reserves for Insurance Losses and Loss Adjustment Expenses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross reserves for insurance losses and loss adjustment expenses, beginning balance	$ 122	$ 129	$ 122
Less: Reinsurance recoverable	81	90	88
Net reserves for insurance losses and loss adjustment expenses at January 1,	47	41	39	$ 34
Current year	282	259	360
Prior years	(2)	2	3
Total net insurance losses and loss adjustment expenses incurred	280	261	363
Current year	(246)	(229)	(328)
Prior years	(28)	(30)	(30)
Total net insurance losses and loss adjustment expenses paid or payable	(274)	(259)	(358)
Plus: Reinsurance recoverable	72	81	90
Gross reserves for insurance losses and loss adjustment expenses, ending balance	$ 119	$ 122	$ 129