Commitments And Contingencies Commitments and Contingencies (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($)
Consumer Loan [Member]
Other Commitments [Line Items]
Purchase commitment	$ 100.0
Purchases made in connection with purchase commitments	95.2
Purchase commitment principal balance	375.0
Purchases made in connection with purchase commitments principal balance	9.8
Non-Exchange Traded Equity Investment in Mortgage Originator
Other Commitments [Line Items]
Guaranty Liabilities	120.0
Flow agreement March 2015 with mortgage originator [Member]
Other Commitments [Line Items]
Purchase commitment	200.0
Purchases made in connection with purchase commitments	64.5
Performance Guarantee [Member]
Other Commitments [Line Items]
Participation Interest in Repo Facility	10.0
Amount of Utilization	$ 164.3
Additional amount to be posted	5.00%
Financing Duration	6 months
Maximum Borrowings under Repo Facility	$ 200.0