Equity Investments - Activity of the Trust's Equity Investments (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Schedule of Equity Method Investments [Line Items]
Capitalized interest	$ 2,053	$ 0
Vintage Housing Holdings, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Investment lag period	1 month
WRT-Elad One South State Equity LP [Member]
Schedule of Equity Method Investments [Line Items]
Investment lag period	1 month
WRT One South State Lender LP [Member]
Schedule of Equity Method Investments [Line Items]
Investment lag period	1 month
WRT-Fenway Wateridge LLC [Member]
Schedule of Equity Method Investments [Line Items]
Investment lag period	1 month
701 7th WRT Investors LLC [Member]
Schedule of Equity Method Investments [Line Items]
Investment lag period	3 months
Capitalized interest	$ 2,053