Reserves for Insurance Losses and Loss Adjustment Expenses Reserves for Insurance Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Gross reserves for insurance losses and loss adjustment expenses			$ 134	$ 140
Reinsurance recoverable			96	108
Net reserves for insurance losses and loss adjustment expenses			38	32
Net insurance losses and loss adjustment expenses, current year			259	235
Net insurance losses and loss adjustment expenses, prior years			1	6
Net insurance losses and loss adjustment expenses incurred	$ 74	$ 77	260	241
Net insurance losses and loss adjustment expenses paid or payable, current year			(227)	(205)
Net insurance losses and loss adjustment expenses paid or payable, prior years			(29)	(27)
Total net insurance losses and loss adjustment expenses paid or payable			(256)	(232)
Net reserves for insurance losses and loss adjustment expenses	42	41	42	41
Reinsurance recoverable	93	98	93	98
Gross reserves for insurance losses and loss adjustment expenses	$ 135	$ 139	$ 135	$ 139