Subsequent Events - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Feb. 26, 2014 Subsequent Event [Member] Newbury Apartments Property [Member]	Mar. 05, 2014 Subsequent Event [Member] Freed Management [Member] ShoppingCenter Number_of_Extensions	Jan. 10, 2014 Subsequent Event [Member] Playa Vista Mezzanine Loan [Member]
Subsequent Events [Line Items]
Mortgage loan on real estate, increase in principal balance						$ 4,000,000
Mortgage loan on real estate, increase in interest rate						1.50%
Mortgage loan on real estate, revised interest rate						16.25%
Mortgage loan on real estate, share in increased loan amount						2,000,000
Mortgage loan on real estate, funded amount						1,375,000
Proceeds from sale of interest in real estate property	38,690,000	7,024,000	3,629,000	27,500,000
Loan secured by limited partnership interests, face amount					15,500,000
Number of retail shopping centers held					2
General partnership interest acquired, aggregate price					500,000
Loan secured by limited partnership interests, basis spread on variable rate					12.00%
Loan secured by limited partnership interests, increase in basis spread on variable rate in each extended term					1.00%
Loan secured by limited partnership interests, stated current interest rate					10.00%
Loan secured by limited partnership interests, annual increase in stated current interest rate					50.00%
Loan secured by limited partnership interests, term					3 years
Loan secured by limited partnership interests, number of extension terms					2
Loan secured by limited partnership interests, term of extension					1 year
Description of trusts participation interest in loan					Upon satisfaction of the loan, the Trust will be entitled to a participation interest equal to the greater of (i) a 14.5% IRR (increasing to 15.5% IRR after the initial term) and (ii) 30% (increasing by 40% after the initial term and 50% after the first extended term) of the value of the properties in excess of $115,000,000
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%
Loan participation interest percentage after extended term					50.00%
Minimum value of properties for entitlement to loan participation interest					$ 115,000,000