Fair Value of Financial Instruments (Schedule of Assets and Liabilities, Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 9.1	$ 6.3
Restricted cash and cash equivalents	225.7	167.4
Restricted securities available for sale	49.1	48.3
Net investment in Loans receivable	3,401.3	3,126.3
Revolving secured line of credit	36.3	57.7
Secured financing (1)	1,756.0	1,471.9
Senior notes	522.9	549.6
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	9.1	6.3
Restricted cash and cash equivalents	225.7	167.4
Restricted securities available for sale	39.8	38.7
Senior notes	522.9	549.6
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted securities available for sale	9.3	9.6
Revolving secured line of credit	36.3	57.7
Secured financing (1)	1,756.0	1,471.9
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net investment in Loans receivable	$ 3,401.3	$ 3,126.3