Fair Value of Financial Instruments (Schedule of Assets and Liabilities, Measured at Fair Value on a Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 6.7	$ 4.2
Restricted cash and cash equivalents	156.6	111.3
Restricted securities available for sale	54.6	53.6
Net investment in Loans receivable	2,369.1	2,226.7
Revolving secured line of credit	106.2	102.8
Secured financing	1,255.1	938.9
Mortgages [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes		3.8
Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes	315.0	367.1
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	6.7	4.2
Restricted cash and cash equivalents	156.6	111.3
Restricted securities available for sale	42.1	25.1
Net investment in Loans receivable
Revolving secured line of credit
Secured financing
Level 1 [Member] | Mortgages [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes
Level 1 [Member] | Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes	315.0	367.1
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents
Restricted cash and cash equivalents
Restricted securities available for sale	12.5	28.5
Net investment in Loans receivable
Revolving secured line of credit	106.2	102.8
Secured financing	1,255.1	938.9
Level 2 [Member] | Mortgages [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes		3.8
Level 2 [Member] | Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents
Restricted cash and cash equivalents
Restricted securities available for sale
Net investment in Loans receivable	2,369.1	2,226.7
Revolving secured line of credit
Secured financing
Level 3 [Member] | Mortgages [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes
Level 3 [Member] | Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes