Commitments And Contingencies Commitments and Contingencies (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($)
Consumer Loan [Member]
Other Commitments [Line Items]
Purchase Commitment, Remaining Minimum Amount Committed	$ 34.1
Purchase commitment	100.0
Purchases made in connection with purchase commitments	85.0
Purchase commitment principal balance	375.0
Purchases made in connection with purchase commitments principal balance	2.7
Mortgage Originator [Member]
Other Commitments [Line Items]
Commitments - Debt or Equity Investment	2.0
Mortgage Originator [Member] | Due on or before June 12, 2016 [Member]
Other Commitments [Line Items]
Commitments - Debt or Equity Investment	2.0
Non-Exchange Traded Equity Investment in Mortgage Originator
Other Commitments [Line Items]
Guaranty Liabilities	12.5
Flow agreement March 2015 with mortgage originator [Member]
Other Commitments [Line Items]
Purchase commitment	200.0
Purchases made in connection with purchase commitments	24.0
Mortgage Loan Purchase Commitments [Member] | Flow agreement March 2015 with mortgage originator [Member]
Other Commitments [Line Items]
Derivative Asset, Notional Amount	13.6
Performance Guarantee [Member]
Other Commitments [Line Items]
Participation Interest in Repo Facility	10.0
Amount of Utilization	$ 123.6
Additional amount to be posted	5.00%
Financing Duration	6 months
Maximum Borrowings under Repo Facility	$ 200.0