Debt and Preferred Equity Investments (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Loan loss reserve activity
Balance at beginning of year		$ 50,175	$ 61,361	$ 61,361
Expensed	2,500	3,000	2,500	10,875
Recoveries	(1,200)	(2,436)	(4,400)	(4,370)
Charge-offs		(9,689)		(17,691)
Balance at end of period		$ 41,050		$ 50,175