Debt and Preferred Equity Investments (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loan loss reserve activity
Balance at beginning of year	$ 1,000	$ 7,000	$ 50,175
Expensed	0	0	3,000
Recoveries	0	0	(2,436)
Charge-offs and reclassifications	(1,000)	(6,000)	(43,739)
Balance at end of period	$ 0	$ 1,000	$ 7,000