Summary of Significant Accounting Policies - VIE & Fair Value (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2017
Variable Interest Entities
REO assets as a percent of consolidated VIE assets			4.00%
Loans as a percent of consolidated VIE assets			96.00%
Fair Value Measurements
Permitted reinvestment under static investment in VIEs			$ 0.0
Reclassifications
Impairment of lease intangible assets	$ 0.7	$ 0.7
Minimum
Lease Classification
Term of lease as a percent of leased asset’s remaining useful life to determine lease classification			75.00%
Minimum lease payments present value percentage in excess of leased asset’s fair value to determine lease classification			90.00%