Equity Investments - Additional Information (Detail) - USD ($)		1 Months Ended	3 Months Ended		6 Months Ended	12 Months Ended
		Jun. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Discount rate				8.00%
Market rent growth rate				2.00%
Expense growth rate				2.00%
Loan receivable, stated interest rate						13.54%	12.78%
Mortgage loans, outstanding balance	[1]					$ 5,280,000
First Priority Mortgage Loan [Member]
Schedule of Equity Method Investments [Line Items]
Debt instrument, description of variable rate basis						40.00%
Interest bearing loan, description of variable rate basis						LIBOR plus 40%
Northwest Atlanta Partners LP [Member]
Schedule of Equity Method Investments [Line Items]
Discount rate			10.80%
Terminal capitalization rate			8.50%
Market rent growth rate			2.70%
Expense growth rate			2.80%
Sealy [Member]
Schedule of Equity Method Investments [Line Items]
Investments other-than-temporarily impaired					$ 1,660,000
Marc Realty [Member]
Schedule of Equity Method Investments [Line Items]
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
Investments other-than-temporarily impaired		$ 762,000
Marc Investments [Member]
Schedule of Equity Method Investments [Line Items]
Investments other-than-temporarily impaired								$ 7,687,000
Equity interest, carrying value								14,438,000
Equity interest, fair value								$ 6,751,000
WRT-Elad One South State Equity LP [Member]
Schedule of Equity Method Investments [Line Items]
Lag in reporting period						1 month
RE CDO Management LLC [Member]
Schedule of Equity Method Investments [Line Items]
Acquired interest in first priority mortgage loan						5.52%
Interest bearing loan, description of variable rate basis						RE CDO holds a 5.52% interest in (i) a first priority mortgage loan collateralized by land located in Las Vegas, Nevada (the “LV 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 $76,733,000 at December 31, 2015, and (ii) a second priority mortgage loan collateralized by the LV Land which bears interest at 10% per annum, all of which accrues, and which had an outstanding balance of $47,515,000 at December 31, 2015. 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%
Payment to acquire interest in mortgage loan						$ 1,093,000
RE CDO Management LLC [Member] | First Mortgage [Member]
Schedule of Equity Method Investments [Line Items]
Mortgage loans, outstanding balance						76,733,000
RE CDO Management LLC [Member] | Original Mortgage [Member]
Schedule of Equity Method Investments [Line Items]
Mortgage loans, outstanding balance						$ 47,515,000
Mortgage loans, interest rate						10.00%
Vintage Housing Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Lag in reporting period						1 month
WRT One South State Lender LP [Member]
Schedule of Equity Method Investments [Line Items]
Loan receivable, face amount						$ 55,714,000
Loan receivable, stated interest rate						15.00%
Loan receivable, maturity period						2017-12
WRT-Fenway Wateridge LLC [Member]
Schedule of Equity Method Investments [Line Items]
Lag in reporting period						1 month
701 Seventh WRT Investor LLC [Member]
Schedule of Equity Method Investments [Line Items]
Lag in reporting period						3 months

[1] Carrying amount represents the estimated amount expected to be collected on disposition of the loan, plus contractual interest receivable at December 31, 2015.