Loan Participations Payable, net (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Loans Receivable Net of Deferred Income		$ 1,523,543		$ 1,288,662
Loan Participations Payable, net		141,452		0
Unfunded Commitments		790,238
Proceeds from loan participations payable		138,075	$ 0
Loan Participation Payable One [Domain]
Transfers Accounted for as Loan Participations Payable, Assets, Carrying Amount		100,000
Loans Receivable, Commitments		250,000
Loans Receivable, Funded Commitment		38,900
Unfunded Commitments		$ 61,100
Loans Receivable with Fixed Rates of Interest		5.90%
Loans Receivable, Amount Funded to Borrower		$ 3,400
Proceeds from loan participations payable		$ 38,900
Loan Participation Payable Two [Domain]
Debt Instrument, Description of Variable Rate Basis	[1]	LIBOR
Loan Receivable, Basis Spread on Variable Rate		3.50%
Transfers Accounted for as Loan Participations Payable, Assets, Carrying Amount		$ 100,000
Loans Receivable, Commitments		220,200
Loans Receivable, Funded Commitment		100,000
Proceeds from loan participations payable		99,200
Loan Participations Payable [Member]
Loans Receivable Net of Deferred Income		142,300
Loan Participations Payable, net		142,300		$ 0
Loan Participations Payable [Member]
Loan Participations Payable, net		$ 141,500
Minimum [Member] | Loan Participation Payable Two [Domain]
Debt Instrument, Basis Spread on Variable Rate		0.25%

[1] The loan has a LIBOR floor of 1.25%. As of June 30, 2015, inclusive of the floor, the 2012 Tranche A-2 Facility loan incurred interest at a rate of 7.00%.