Debt and Preferred Equity Investments (Preferred Equity Investments)(Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Preferred equity investment
Aggregate weighted average current yield (as a percent)	9.55%
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 1,357,181	$ 1,670,020
Preferred Equity, March 2018
Preferred equity investment
Future Funding Obligations	0
Senior Financing	71,486
Carrying Value, Net of Discounts and Deferred Origination Fees	9,974	9,967
Preferred Equity, November 2018
Preferred equity investment
Future Funding Obligations	4,779
Senior Financing	59,966
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 33,062	32,209
Preferred equity investments
Preferred equity investment
Aggregate weighted average current yield (as a percent)	7.97%
Future Funding Obligations	$ 4,779
Senior Financing	131,452
Carrying Value, Net of Discounts and Deferred Origination Fees	$ 43,036	$ 42,176