Reserves for Insurance Losses and Loss Adjustment Expenses 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, 2019	Dec. 31, 2018	Dec. 31, 2017
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross reserves for insurance losses and loss adjustment expenses	$ 134	$ 140	$ 149
Reinsurance recoverable	96	108	108
Net reserves for insurance losses and loss adjustment expenses	38	32	41
Net insurance losses and loss adjustment expenses, current year	321	291	332
Net insurance losses and loss adjustment expenses, prior years	0	4	0
Net insurance losses and loss adjustment expenses incurred	321	295	332
Net insurance losses and loss adjustment expenses paid or payable, current year	(295)	(263)	(309)
Net insurance losses and loss adjustment expenses paid or payable, prior years	(30)	(26)	(32)
Total net insurance losses and loss adjustment expenses paid or payable	(325)	(289)	(341)
Net reserves for insurance losses and loss adjustment expenses	34	38	32
Reinsurance recoverable	88	96	108
Gross reserves for insurance losses and loss adjustment expenses	$ 122	$ 134	$ 140