Loans Receivable - Summary of Trust's Loans Receivable (Parenthetical) (Detail)	6 Months Ended
	Jun. 30, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Extension Option Period	1 year
Whole Loan [Member] | Hotel Wales [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Libor floor	3.00%
Whole Loan [Member] | Queensridge [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Libor floor	0.50%
Mezzanine [Member] | Renaissance Walk [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Libor floor	2.00%
Mezzanine [Member] | Playa Vista [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Libor floor	0.50%