Equity Investments - Activity of the Trust's Equity Investments (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Vintage Housing Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Investment lag Period	1 month	1 month
WRT-Elad One South State Equity LP [Member]
Schedule of Equity Method Investments [Line Items]
Investment lag Period	1 month	1 month
WRT-One South State Lender LP [Member]
Schedule of Equity Method Investments [Line Items]
Investment lag Period	1 month	1 month
701 7th WRT Investors LLC [Member]
Schedule of Equity Method Investments [Line Items]
Investment lag Period	3 months	3 months
WRT-Fenway Wateridge LLC [Member]
Schedule of Equity Method Investments [Line Items]
Investment lag Period	1 month	1 month