Equity Investments - Activity of the Trust's Equity Investments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Schedule of Equity Method Investments [Line Items]
Beginning Balance	$ 149,085
Investment in equity	40,002
Equity Income (loss)	6,194	7,869
Distributions	(4,344)
Sales Price	(200)
Ending Balance	190,737
Sealy [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	7,635
Investment in equity
Equity Income (loss)	(128)
Distributions
Sales Price
Ending Balance	7,507
Vintage Housing Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	34,153
Investment in equity
Equity Income (loss)	1,620
Distributions	(1,387)
Sales Price
Ending Balance	34,386
WRT-Elad One South State Equity LP [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance
Investment in equity
Equity Income (loss)
Distributions
Sales Price
Ending Balance
WRT One South State Lender LP [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	23,661
Investment in equity
Equity Income (loss)	1,236
Distributions	(970)
Sales Price
Ending Balance	23,927
WRT-Fenway Wateridge LLC [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	1,898
Investment in equity	39
Equity Income (loss)	52
Distributions
Sales Price
Ending Balance	1,989
701 7th WRT Investors LLC [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	55,259
Investment in equity	39,698
Equity Income (loss)	1,558
Distributions	(368)
Sales Price
Ending Balance	96,147
WRT-Stamford LLC [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	9,064
Investment in equity
Equity Income (loss)	229
Distributions	(85)
Sales Price
Ending Balance	9,208
10 Metrotech Loan LLC [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	11
Investment in equity
Equity Income (loss)
Distributions
Sales Price
Ending Balance	11
RE CDO Management LLC [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	992
Investment in equity
Equity Income (loss)	4
Distributions
Sales Price
Ending Balance	996
Concord Debt Holdings LLC [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance
Investment in equity
Equity Income (loss)	266
Distributions	(266)
Sales Price
Ending Balance
CDH CDO LLC [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance
Investment in equity
Equity Income (loss)	433
Distributions	(433)
Sales Price
Ending Balance
Concord Debt Holdings LLC (1) [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	966
Investment in equity
Equity Income (loss)	90
Distributions	(266)
Sales Price
Ending Balance	790
CDH CDO LLC (1) [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	4,215
Investment in equity
Equity Income (loss)	833
Distributions	(433)
Sales Price
Ending Balance	4,615
Mentor Retail LLC [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	635
Investment in equity
Equity Income (loss)	20
Distributions	(70)
Sales Price
Ending Balance	585
Marc Realty [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	6,751
Investment in equity
Equity Income (loss)	(5)
Distributions
Sales Price	(200)
Ending Balance	6,546
WRT - ROIC Lakeside Eagle LLC [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance
Investment in equity	15
Equity Income (loss)	(11)
Distributions
Sales Price
Ending Balance	4
Atrium Mall LLC [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance	3,845
Investment in equity
Equity Income (loss)	(3)
Distributions	(66)
Sales Price
Ending Balance	3,776
Edens [Member]
Schedule of Equity Method Investments [Line Items]
Beginning Balance
Investment in equity	250
Equity Income (loss)
Distributions
Sales Price
Ending Balance	$ 250