Loans Receivable - Summary of Trust's Loans Receivable (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended			3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		3 Months Ended		0 Months Ended	3 Months Ended		3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Hotel Wales [Member] Whole Loan [Member]	Dec. 31, 2013 Hotel Wales [Member] Whole Loan [Member]	Mar. 31, 2014 The Shops at Wailea [Member] B Note [Member]	Dec. 31, 2013 The Shops at Wailea [Member] B Note [Member]	Mar. 31, 2014 Legacy Orchard Loan [Member] Corporate Loan [Member]	Dec. 31, 2013 Legacy Orchard Loan [Member] Corporate Loan [Member]	Mar. 31, 2014 Queensridge [Member] Whole Loan [Member]	Dec. 31, 2013 Queensridge [Member] Whole Loan [Member]	Mar. 31, 2014 San Marbeya [Member] Whole Loan [Member]	Dec. 31, 2013 San Marbeya [Member] Whole Loan [Member]	Mar. 31, 2014 Churchill, PA [Member] Whole Loan [Member]	Dec. 31, 2013 Churchill, PA [Member] Whole Loan [Member]	Mar. 31, 2014 1515 Market [Member] Whole Loan [Member]	Mar. 31, 2014 Playa Vista Waters Edge [Member] Mezzanine [Member]	Dec. 31, 2013 Playa Vista Waters Edge [Member] Mezzanine [Member]	Mar. 31, 2014 Rockwell [Member] Mezzanine [Member]	Dec. 31, 2013 Rockwell [Member] Mezzanine [Member]	Mar. 31, 2014 500-512 7th Ave [Member] B Note [Member]	Dec. 31, 2013 500-512 7th Ave [Member] B Note [Member]	Mar. 31, 2014 Pinnacle II [Member] B Note [Member]	Dec. 31, 2013 Pinnacle II [Member] B Note [Member]	Mar. 31, 2014 Popiu Shopping Village [Member] B Note [Member]	Dec. 31, 2013 Popiu Shopping Village [Member] B Note [Member]	Mar. 31, 2014 Wellington Tower [Member] Mezzanine [Member]	Dec. 31, 2013 Wellington Tower [Member] Mezzanine [Member]	Mar. 31, 2014 Mentor Building [Member] Whole Loan [Member]	Dec. 31, 2013 Mentor Building [Member] Whole Loan [Member]	Mar. 05, 2014 Marc Realty [Member]	Mar. 31, 2014 Marc Realty [Member] Mezzanine [Member]	Dec. 31, 2013 Marc Realty [Member] Mezzanine [Member]	Mar. 31, 2014 Norridge [Member] Mezzanine [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage Loans, Stated Interest Rate, Variable Rate Basis					6.15								LIBOR + 3.75 %			LIBOR + 15.75 %		12.0				6.31		6.62				10.0			6.00		LIBOR + 12 %
Interest rate on mortgage loans					6.15%								3.75%			15.75%		12.00%				6.31%		6.62%				10.00%		6.00%	6.00%		12.00%
Loans receivable, net	$ 48,667	$ 101,100		$ 20,101	$ 6,559	$ 6,292		$ 9,750		$ 2,942		$ 28,546	$ 372	$ 683		$ 12,346	$ 10,327				$ 10,250	$ 4,644	$ 4,648	$ 2,087	$ 2,058		$ 2,991	$ 2,512	$ 2,512		$ 4,523		$ 15,624
Contractual Maturity Date					Oct. 06, 2014								Jun. 01, 2015			Jan. 23, 2015		May 01, 2016				Sep. 06, 2016		Jan. 06, 2017				Sep. 10, 2017			Mar. 01, 2017		Mar. 09, 2017