Fair Value of Financial Instruments (Schedule of Assets and Liabilities, Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 134.7	$ 6.4
Restricted cash and cash equivalents	176.0	157.6
Restricted securities available for sale	50.5	53.2
Net investment in Loans receivable	2,977.2	2,517.3
Revolving secured line of credit		119.5
Secured financing	1,532.6	1,334.7
Senior notes	557.9	299.3
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	134.7	6.4
Restricted cash and cash equivalents	176.0	157.6
Restricted securities available for sale	40.8	47.8
Senior notes	557.9	299.3
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted securities available for sale	9.7	5.4
Revolving secured line of credit		119.5
Secured financing	1,532.6	1,334.7
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net investment in Loans receivable	$ 2,977.2	$ 2,517.3