Fair Value of Financial Instruments (Schedule of Comparison of the Carrying Value and Estimated Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions		Mar. 31, 2016	Dec. 31, 2015
Assets
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
Liabilities
Revolving secured line of credit		36.3	57.7
Secured financing (1)		1,756.0	1,471.9
Senior notes		522.9	549.6
Carrying Amount [Member]
Assets
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		3,363.4	3,101.5
Liabilities
Revolving secured line of credit		36.3	57.7
Secured financing (1)	[1]	1,751.7	1,470.1
Senior notes	[1]	540.3	540.0
Estimated Fair Value [Member]
Assets
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
Liabilities
Revolving secured line of credit		36.3	57.7
Secured financing (1)	[1]	1,756.0	1,471.9
Senior notes	[1]	$ 522.9	$ 549.6

[1] Prior year carrying amounts have been reclassified to reflect the adoption of ASU 2015-03, as amended by ASU No. 2015-15, which resulted in a reclassification of certain deferred debt issuance costs from other assets to secured financing and senior notes.