Equity Investments (Details 1) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			$ 162,142,000
Contributions			33,546,000	59,562,000
Equity Income (loss)	586,000	2,875,000	1,010,000	1,520,000
Distributions			4,788,000	3,813,000
Sales			2,297,000	6,000,000
Equity Method Investments, Closing Balance	146,221,000		146,221,000
Marc Realty [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			27,145,000
Contributions			8,150,000
Equity Income (loss)			(344,000)
Distributions			(533,000)
Sales			(12,650,000)
Equity Method Investments, Closing Balance	21,768,000		21,768,000
Sealy [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			11,348,000
Equity Income (loss)			(1,631,000)
Equity Method Investments, Closing Balance	9,717,000		9,717,000
Concord Debt Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Equity Income (loss)			351,000
Distributions			(351,000)
CDH CDO [Member]
Schedule of Equity Method Investments [Line Items]
Equity Income (loss)			534,000
Distributions			(534,000)
Concord Debt Holdings (1) [Member]
Schedule of Equity Method Investments [Line Items]
Contributions			4,501,000
Equity Income (loss)			28,000
Equity Method Investments, Closing Balance	4,529,000		4,529,000
CDH CDO LLC (1) [Member]
Schedule of Equity Method Investments [Line Items]
Contributions			2,500,000
Equity Income (loss)			478,000
Equity Method Investments, Closing Balance	2,978,000		2,978,000
WRT - ROIC Riverside [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			7,883,000
Equity Income (loss)			468,000
Distributions			(468,000)
Equity Method Investments, Closing Balance	7,883,000		7,883,000
WRT - ROIC Lakeside Eagle [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			7,000
Contributions			10,000
Equity Income (loss)			(16,000)
Equity Method Investments, Closing Balance	1,000		1,000
Socal Office Portfolio Loan [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			72,626,000
Equity Income (loss)			(638,000)
Distributions			(38,100,000)
Equity Method Investments, Closing Balance	33,888,000		33,888,000
RE CDO Management [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			1,296,000
Contributions			550,000
Equity Income (loss)			28,000
Distributions			(80,000)
Equity Method Investments, Closing Balance	1,794,000		1,794,000
Vintage Housing [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			29,887,000
Contributions			2,029,000
Equity Income (loss)			934,000
Distributions			(2,706,000)
Equity Method Investments, Closing Balance	30,144,000		30,144,000
FII Co-Invest [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			1,800,000
Sales			(1,800,000)
WRT-Elad One South Street Equity LP [Member]
Schedule of Equity Method Investments [Line Items]
Contributions			2,837,000
Equity Income (loss)			(750,000)
Equity Method Investments, Closing Balance	2,087,000		2,087,000
WRT-Elad One South Street Lender LP[Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			10,150,000
Contributions			11,214,000
Equity Income (loss)			1,265,000
Equity Method Investments, Closing Balance	22,629,000		22,629,000
WRT-Stamford [Member]
Schedule of Equity Method Investments [Line Items]
Contributions			8,036,000
Equity Income (loss)			316,000
Distributions			(116,000)
Equity Method Investments, Closing Balance	8,236,000		8,236,000
10 Metrotech [Member]
Schedule of Equity Method Investments [Line Items]
Contributions			75,000
Equity Income (loss)			(19,000)
Equity Method Investments, Closing Balance	56,000		56,000
Mentor [Member]
Schedule of Equity Method Investments [Line Items]
Contributions			505,000
Equity Income (loss)			6,000
Equity Method Investments, Closing Balance	511,000		511,000
Total [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			162,142,000
Contributions			40,407,000
Equity Income (loss)			1,010,000
Distributions			(42,888,000)
Sales			(14,450,000)
Equity Method Investments, Closing Balance	$ 146,221,000		$ 146,221,000