Loans Receivable - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		12 Months Ended	0 Months Ended
	Aug. 31, 2014	Mar. 31, 2015	Mar. 31, 2014 Loans	Dec. 31, 2014	Feb. 05, 2015	Aug. 31, 2013
Receivables [Line Items]
Loans receivable, accrued interest		$ 29,000		$ 218,000
Weighted average coupon rate on loans receivable		8.09%		10.55%
Weighted average yield to maturity		13.85%		12.78%
Provision for loan loss			0
Number of non-performing loans with past due payments			1
Period for the return of assets		2 years
Annual interest rate	15.00%
Lender LP [Member]
Receivables [Line Items]
Secured financing receivable						30,000,000
Edens Center and Norridge Commons [Member]
Receivables [Line Items]
Principal payment of loans					15,275,000
Outstanding principal balance on loan receivable		157,000
Loan participation interest IRR percentage		14.50%
Loan participation interest IRR percentage after initial term		15.50%
Loan participation interest percentage		30.00%
Loan participation interest percentage after initial term		40.00%
Minimum value of properties for entitlement to loan participation interest		115,000,000
Description of Trust's participation interest in loan		Upon satisfaction of the loan, the Trust is entitled to a participation interest equal to the greater of (i) a 14.5% internal rate of return (“IRR”) (increasing to a 15.5% IRR after March 9, 2017) and (ii) 30% (increasing to 40% after March 9, 2017 and 50% after March 9, 2018) of the value of the properties in excess of $115,000,000.
Loan participation interest percentage after initial term		50.00%
Elad Canada Ltd [Member] | Lender LP [Member]
Receivables [Line Items]
Rate of interest for acquisition						50.00%
Secured Financing Receivable [Member]
Receivables [Line Items]
Interest income		$ 941,000