Equity Investments (Details 1) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			$ 162,142,000
Contributions			47,925,000	67,901,000
Equity in income of equity investments	12,644,000	2,820,000	13,654,000	4,340,000
Distributions			17,097,000	8,081,000
Sales			2,297,000	6,000,000
Equity Method Investments, Closing Balance	115,299,000		115,299,000
Vintage Housing [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			29,887,000
Contributions			2,029,000
Equity in income of equity investments			2,326,000
Distributions			(4,159,000)
Sales
Equity Method Investments, Closing Balance	30,083,000		30,083,000
WRT-Elad One South Street Equity LP [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance
Contributions			2,838,000
Equity in income of equity investments			(1,797,000)
Distributions
Sales
Equity Method Investments, Closing Balance	1,041,000		1,041,000
W R T Elad One South Street Lender L P [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			10,150,000
Contributions			11,213,000
Equity in income of equity investments			2,255,000
Distributions
Sales
Equity Method Investments, Closing Balance	23,618,000		23,618,000
WRT-Stamford [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance
Contributions			8,036,000
Equity in income of equity investments			548,000
Distributions			(217,000)
Sales
Equity Method Investments, Closing Balance	8,367,000		8,367,000
10 Metrotech Loan LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance
Contributions			10,915,000
Equity in income of equity investments			31,000
Distributions			(101,000)
Sales
Equity Method Investments, Closing Balance	10,845,000		10,845,000
RE CDO Management [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			1,296,000
Contributions			550,000
Equity in income of equity investments			46,000
Distributions			(100,000)
Sales
Equity Method Investments, Closing Balance	1,792,000		1,792,000
Mentor Retail LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance
Contributions			505,000
Equity in income of equity investments			18,000
Distributions
Sales
Equity Method Investments, Closing Balance	523,000		523,000
Concord Debt Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance
Contributions
Equity in income of equity investments			386,000
Distributions			(386,000)
Sales
Equity Method Investments, Closing Balance
C D H C D O L L C [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance
Contributions
Equity in income of equity investments			670,000
Distributions			(670,000)
Sales
Equity Method Investments, Closing Balance
Concord Debt Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance
Contributions			4,501,000
Equity in income of equity investments			30,000
Distributions			(36,000)
Sales
Equity Method Investments, Closing Balance	4,495,000		4,495,000
C D H C D O L L C One [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance
Contributions			2,500,000
Equity in income of equity investments			1,333,000
Distributions			(135,000)
Sales
Equity Method Investments, Closing Balance	3,698,000		3,698,000
Sealy [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			11,348,000
Contributions
Equity in income of equity investments			(2,444,000)
Distributions
Sales
Equity Method Investments, Closing Balance	8,904,000		8,904,000
Marc Realty [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			27,145,000
Contributions			11,674,000
Equity in income of equity investments			(132,000)
Distributions			(4,116,000)
Sales			(12,650,000)
Equity Method Investments, Closing Balance	21,921,000		21,921,000
WRT - ROIC Lakeside Eagle [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			7,000
Contributions			25,000
Equity in income of equity investments			(32,000)
Distributions
Sales
Equity Method Investments, Closing Balance
ROIC - Riverside LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			7,883,000
Contributions
Equity in income of equity investments			706,000
Distributions			(8,589,000)
Sales
Equity Method Investments, Closing Balance
Socal Office Portfolio Loan [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			72,626,000
Contributions
Equity in income of equity investments			9,710,000
Distributions			(82,324,000)
Sales
Equity Method Investments, Closing Balance	12,000		12,000
FII Co-Invest [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments, Beginning Balance			1,800,000
Contributions
Equity in income of equity investments
Distributions
Sales			(1,800,000)
Equity Method Investments, Closing Balance