Debt and Preferred Equity Investments (Narrative)(Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) segment	Dec. 31, 2016 USD ($)
Preferred equity investment
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 1,627,836	$ 1,640,412
Number of portfolio segments of financial receivables (segment) | segment	1
Additional amount of financing receivables included in other assets	$ 90,300	$ 99,500