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, 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	$ 129	$ 122	$ 134
Reinsurance recoverable	90	88	96
Net reserves for insurance losses and loss adjustment expenses, beginning balance	39	34	38
Net insurance losses and loss adjustment expenses, current year	259	360	321
Net insurance losses and loss adjustment expenses, prior years	2	3	0
Total net insurance losses and loss adjustment expenses incurred	261	363	321
Net insurance losses and loss adjustment expenses paid or payable, current year	(229)	(328)	(295)
Net insurance losses and loss adjustment expenses paid or payable, prior years	(30)	(30)	(30)
Total net insurance losses and loss adjustment expenses paid or payable	(259)	(358)	(325)
Net reserves for insurance losses and loss adjustment expenses, ending balance	41	39	34
Reinsurance recoverable	81	90	88
Gross reserves for insurance losses and loss adjustment expenses, ending balance	$ 122	$ 129	$ 122