Reserves for Insurance Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross reserves for insurance losses and loss adjustment expenses	$ 140	$ 149	$ 169
Reinsurance recoverable	108	108	120
Net reserves for insurance losses and loss adjustment expenses	32	41	49
Net insurance losses and loss adjustment expenses, current year	291	332	345
Net insurance losses and loss adjustment expenses, prior years	4	0	(3)
Net insurance losses and loss adjustment expenses incurred	295	332	342
Net insurance losses and loss adjustment expenses paid or payable, current year	(263)	(309)	(320)
Net insurance losses and loss adjustment expenses paid or payable, prior years	(26)	(32)	(30)
Total net insurance losses and loss adjustment expenses paid or payable	(289)	(341)	(350)
Net reserves for insurance losses and loss adjustment expenses	38	32	41
Reinsurance recoverable	96	108	108
Gross reserves for insurance losses and loss adjustment expenses	$ 134	$ 140	$ 149