Equity Investments - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended					0 Months Ended	12 Months Ended													0 Months Ended					12 Months Ended					1 Months Ended	12 Months Ended	1 Months Ended	0 Months Ended	12 Months Ended		0 Months Ended	12 Months Ended				12 Months Ended
	Jan. 02, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Sullivan Center [Member]	Dec. 31, 2013 First Priority Mortgage Loan [Member]	Jan. 02, 2012 Marc Realty [Member]	Dec. 31, 2013 Marc Realty [Member]	Dec. 31, 2013 Marc Realty [Member] Minimum [Member]	Dec. 31, 2013 Marc Realty [Member] Maximum [Member]	Dec. 31, 2013 Sealy [Member]	Dec. 31, 2012 Sealy [Member]	Dec. 31, 2013 Marc Investments [Member]	Dec. 31, 2013 Concord Debt Holdings LLC [Member]	Dec. 31, 2012 Concord Debt Holdings LLC [Member]	Dec. 31, 2013 CDH CDO LLC [Member]	Dec. 31, 2012 CDH CDO LLC [Member]	Dec. 31, 2011 Sealy Northwest Atlanta [Member]	Dec. 31, 2011 Sealy Newmarket [Member]	Dec. 31, 2011 Sealy Airpark Nashville [Member]	Mar. 01, 2012 3701 Algonquin Road LLC [Member] Marc Realty [Member]	May 31, 2012 Salt Creek LLC [Member] Marc Realty [Member]	May 31, 2012 River Road LLC [Member] Marc Realty [Member]	May 31, 2012 900 Ridgebrook LLC [Member] Marc Realty [Member]	May 31, 2012 Michigan 30 LLC [Member] Marc Realty [Member]	Dec. 31, 2013 Vintage Housing Holdings [Member] Partner	Dec. 31, 2012 Vintage Housing Holdings [Member]	Dec. 31, 2013 Vintage Housing Holdings [Member] Lynnwood [Member] Project	Dec. 31, 2013 Vintage Housing Holdings [Member] Marysville [Member] Project	Dec. 31, 2013 Vintage Housing Holdings [Member] California and Nevada [Member] Project	Sep. 18, 2012 WRT - ROIC Riverside LLC [Member]	Dec. 31, 2012 WRT - ROIC Riverside LLC [Member]	Sep. 18, 2012 WRT - ROIC Riverside LLC [Member] ROIC [Member]	Sep. 29, 2012 SoCal Office Portfolio Loan [Member]	Dec. 31, 2012 SoCal Office Portfolio Loan [Member]	Dec. 31, 2011 SoCal Office Portfolio Loan [Member]	Sep. 29, 2012 SoCal Office Portfolio Loan [Member] New Valley/Starwood [Member]	Dec. 31, 2013 RE CDO Management LLC [Member]	Dec. 31, 2012 RE CDO Management LLC [Member]	Dec. 31, 2011 RE CDO Management LLC [Member]	Dec. 31, 2013 RE CDO Management LLC [Member] First Mortgage [Member]	Dec. 31, 2013 RE CDO Management LLC [Member] Original Mortgage [Member]	Dec. 31, 2013 WRT-One South State Lender LP [Member]	Dec. 31, 2012 WRT-One South State Lender LP [Member]	Dec. 31, 2011 WRT-One South State Lender LP [Member]
Schedule of Equity Method Investments [Line Items]
Difference in carrying value of investments					$ 11,196,000
Cash distributions amount														3,072,000	422,000
Net income loss														40,493,000		19,605,000
Distributions of income from equity investments		24,112,000	21,593,000	12,696,000												1,020,000	1,715,000
Carrying value of investment		614,420,000	370,436,000								0
Other-than-temporary impairment charges																		2,900,000	900,000	1,494,000
Loans receivable	(2,938,000)	877,000	(2,938,000)
Transfer from preferred equity investments	(3,923,000)		(3,923,000)	(7,843,000)
Equity investments			(6,861,000)	(5,035,000)			(6,861,000)
Interest		(26,000)	22,047,000													(13,000)					250,000	0	1,000,000	1,100,000	10,300,000
Secured promissory note																									6,550,000
Interest in joint venture gross sale price								6,000,000
Period of exercise of option granted to joint venture partner to acquire interest								2 years
Option granted to joint venture partner to acquire interest purchase price range									5,000,000	6,600,000
Investments other-than-temporarily impaired													7,687,000
Equity interest carrying value													14,438,000
Equity interest fair value													6,751,000
Return and share of capital distribution		14,618,000	84,026,000	31,890,000																											7,800,000		15,600,000	38,407,000			44,224,000
Net proceeds received																																			38,100,000
Total assets																																			13,000	97,989,000
Total liabilities																																			0	269,000
Net Income																																			16,892,000	366,000		7,417,000	135,000	93,000			8,420,000	7,251,000
Contributions to the venture																											6,779,000
Trust Invested Amount in properties																												5,500,000
Number of unit multi-family project																												345	204	490
Acquisition of non-controlling partner interests, 204 units																													750,000
Acquisition of non-controlling partner interests, 490 units																										529,000
Interest acquired in Multifamily property number																										2
Acquired Interest in first priority mortgage loan																																						5.52%
Debt Instrument Description of Variable Rate Basis						40.00%
Loan bears interest, description of variable rate basis		LIBOR plus 3%				LIBOR plus 40%																																RE CDO holds a 5.52% interest in (i) a first priority mortgage loan collateralized by land located in Las Vegas, Nevada (the “Land”), which loan bears interest at LIBOR plus 40% with a current pay rate of 7.5% and the balance accruing and compounding and which had an outstanding balance of $21,227,000 at December 31, 2013, and (ii) a second priority mortgage loan collateralized by the Land which bears interest at 10% per annum, all of which accrues, and which had an outstanding balance of $30,401,000 at December 31, 2013. The interest in the loan was acquired for $1,093,000 and RE CDO accounts for this investment on the cost recovery method.
Current pay rate																																						7.50%
First priority mortgage loans outstanding balance		101,100,000																																							21,227,000	30,401,000
Interest rate on mortgage loans																																										10.00%
Payment to acquire interest in mortgage loan																																						1,093,000
Loan receivable face amount																																											$ 51,716,000
Loan receivable stated interest rate		11.59%	11.43%																																								15.00%
Loan receivable maturity period																																											2017-12