Loans Receivable, At Fair Value - Schedule of Loans Receivable on Nonaccrual Status (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013
Senior Mortgages Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Balance
Net Book Value
Subordinated Interests in Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Balance	43,448
Net Book Value
Mezzanine and Other Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Balance	69,146
Net Book Value	11,869
Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Principal Balance	112,594
Net Book Value	$ 11,869