Equity Investments (Details Textual) (USD $)	0 Months Ended	1 Months Ended		3 Months Ended								12 Months Ended						1 Months Ended	12 Months Ended			12 Months Ended		1 Months Ended		1 Months Ended			1 Months Ended				1 Months Ended		1 Months Ended			1 Months Ended	12 Months Ended			1 Months Ended			1 Months Ended		12 Months Ended	1 Months Ended			1 Months Ended			12 Months Ended			12 Months Ended		1 Months Ended	12 Months Ended						1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended			12 Months Ended
	Aug. 06, 2012	Jan. 31, 2012	Jan. 14, 2011	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	May 14, 2012	Feb. 17, 2012	Jun. 30, 2011 Parent Company [Member]	Jan. 31, 2012 Marc Realty [Member]	Dec. 31, 2012 Sealy [Member]	Dec. 31, 2011 Sealy [Member]	Dec. 31, 2010 Sealy [Member]	Dec. 31, 2012 WRT-Elad One South State Equity LP [Member]	Dec. 31, 2011 3701 Algonquin Road LLC [Member]	Mar. 31, 2012 3701 Algonquin Road LLC [Member] Marc Realty [Member]	Dec. 31, 2012 3701 Algonquin Road LLC [Member] Marc Realty [Member]	May 31, 2012 Salt Creek LLC [Member] Marc Realty [Member]	Dec. 31, 2012 Salt Creek LLC [Member] Marc Realty [Member]	Dec. 31, 2011 Salt Creek LLC [Member] Marc Realty [Member]	May 31, 2012 River Road LLC [Member] Marc Realty [Member]	Dec. 31, 2012 River Road LLC [Member] Marc Realty [Member]	Dec. 31, 2011 River Road LLC [Member] Marc Realty [Member]	Dec. 31, 2011 900 Ridgebrook LLC [Member]	May 31, 2012 900 Ridgebrook LLC [Member] Marc Realty [Member]	Dec. 31, 2012 900 Ridgebrook LLC [Member] Marc Realty [Member]	May 31, 2012 Michigan 30 LLC [Member] Marc Realty [Member]	Dec. 31, 2012 Michigan 30 LLC [Member] Marc Realty [Member]	Dec. 31, 2011 Michigan 30 LLC [Member] Marc Realty [Member]	Sep. 30, 2012 WRT - ROIC Riverside LLC [Member]	Dec. 31, 2012 WRT - ROIC Riverside LLC [Member]	Dec. 31, 2011 WRT - ROIC Riverside LLC [Member]	Dec. 31, 2010 WRT - ROIC Riverside LLC [Member]	Sep. 30, 2012 WRT - ROIC Riverside LLC [Member] ROIC [Member]	Dec. 31, 2012 WRT - ROIC Riverside LLC [Member] ROIC [Member]	Dec. 31, 2011 WRT - ROIC Riverside LLC [Member] ROIC [Member]	Sep. 30, 2011 Northwest Atlanta Partners LP [Member]	Jun. 30, 2011 Northwest Atlanta Partners LP [Member]	Dec. 31, 2012 Northwest Atlanta Partners LP [Member] Number sqft	Sep. 30, 2011 Northwest Atlanta Partners LP [Member] Interest rate caps [Member]	Sep. 30, 2011 Northwest Atlanta Partners LP [Member] Parent Company [Member]	Dec. 31, 2012 Northwest Atlanta Partners LP [Member] Affiliated Entity [Member]	Sep. 30, 2011 Northwest Atlanta Partners LP [Member] Sealy [Member]	Dec. 31, 2012 Northwest Atlanta Partners LP [Member] Sealy [Member]	Dec. 31, 2011 Northwest Atlanta Partners LP [Member] Sealy [Member]	Dec. 31, 2012 New Market GP LLC [Member] sqft	Dec. 31, 2012 New Market GP LLC [Member] Sealy [Member]	Dec. 31, 2011 New Market GP LLC [Member] Sealy [Member]	Dec. 31, 2012 Airpark Nashville GP [Member] Property	Dec. 31, 2012 Airpark Nashville GP [Member] Sealy [Member]	May 31, 2012 Lex-Win [Member]	Dec. 31, 2012 Vintage Housing Holdings [Member]	Dec. 31, 2012 Vintage Housing Holdings [Member] Lynnwood [Member]	Dec. 31, 2012 Vintage Housing Holdings [Member] Marysville [Member]	Dec. 31, 2012 Sealy Northwest Atlanta [Member]	Dec. 31, 2012 Sealy Newmarket [Member]	Dec. 31, 2012 Sealy Airpark Nashville [Member]	Sep. 30, 2012 SoCal Office Portfolio Loan [Member]	Dec. 31, 2012 SoCal Office Portfolio Loan [Member]	Dec. 31, 2011 SoCal Office Portfolio Loan [Member]	Sep. 30, 2012 SoCal Office Portfolio Loan [Member] New Valley/Starwood [Member]	Dec. 31, 2012 Concord Debt Holdings LLC [Member]	Dec. 31, 2011 Concord Debt Holdings LLC [Member]	Apr. 30, 2012 Concord Debt Holdings LLC [Member]	Dec. 31, 2012 CDH CDO LLC [Member]	Dec. 31, 2011 CDH CDO LLC [Member]	Apr. 18, 2012 CDH CDO LLC [Member]
Equity Investments (Textual) [Abstract]
Investment lag period																						1 month																																						1 month
Loans receivable		$ 2,938,000,000										$ (2,938,000)
Transfer from preferred equity investments												3,923,000	7,843,000
Equity investments												(6,861,000)	(5,035,000)					(6,861,000)
Interest																								250,000		0			1,000,000				1,100,000		10,300,000
Secured promissory note																																			6,550,000
Return and share of capital distribution																																						7,800,000				15,600,000																								38,407,000			44,224,000
Net proceeds received																																																																			38,100,000
Number of properties																																															12										13
Purchase price of asset																																																						47,000,000			87,200,000
Impairment charges												698,000		2,720,000
Net income loss				(2,088,000)	15,108,000	3,358,000	8,253,000	(9,839,000)	9,846,000	3,728,000	7,198,000	24,631,000	10,933,000	16,477,000
Cash Distributions Amount																																																																						422,000	3,474,000
Distributions												21,593,000	12,696,000	5,270,000					(45,000)	(250,000)																			(8,589,000)	(936,000)																														(422,000)	(3,474,000)		(1,715,000)	(480,000)
Percentage of non-controlling ownership interest																																															60.00%							68.00%			50.00%
Trust Invested Amount in properties																																															5,470,000			3,647,000										5,500,000
Percentage of the ownership																																											50.00%							40.00%		60.00%			68.00%		50.00%	50.00%														33.33%			33.33%
First mortgage loan																																															28,750,000							37,000,000			74,000,000
Interest rate on mortgage loans	9.00%		6.40%									3.95%																																										6.12%			5.77%
Bridge loan to the venture																																														20,641,000
Discounted payoff Amount																																														20,500,000
Gain on the extinguishment of debt												(121,000)	9,258,000																																	9,170,000,000
Accrued interest and penalties																	5,502,000																													2,410,000
Replacement financing amount																																													14,000,000
LIBOR plus															10.00%	3.25%																													5.35%
Purchased interest rate Of LIBOR																																																0.01
Maturity period of the assumed debt												Aug. 15, 2022																																	Sep. 29, 2015			Oct. 01, 2013
Cash proceeds from loan																																																	4,650,000		3,100,000
Maturity												May 2012																																										November 2016
Net of escrows and closing costs																																																									65,383,000
Contribution amount for ownership																																																									9,308,000
Other-than-temporary impairment charges																																																															2,900,000	900,000	1,494,000
Total assets																																																																			13,000,000	97,989,000,000
Total liabilities																																																																			0	269,000,000
Contributions to the venture																																																												6,779,000
Acquisition of non-controlling partner interests, 204 units																																																													750,000
Acquisition of non-controlling partner interests, 490 units																																																														529,000
Net Income																																																																			16,892,000,000	366,000,000
Net income loss																																																																						40,557,000			32,984,000
Acquisition Price																																																											7,000,000
Equity investments				134,859,000				162,142,000				134,859,000	162,142,000	81,937,000					8,104,000	11,348,000	11,904,000	460,000	250,000						1,000,000		1,000,000	1,000,000	1,100,000				10,049,000			7,883,000	7,883,000			7,883,000								8,104,000	8,537,000			2,811,000
Return of capital distribution												$ (84,026,000)	$ (31,890,000)	$ (9,625,000)
Area of property																																															472,000							470,000