STRUCTURED FINANCING PORTFOLIO, NET - Schedule of Notes Receivable (Details) $ in Thousands	1 Months Ended	9 Months Ended
	Feb. 28, 2015 USD ($)	Sep. 30, 2015 USD ($) debtinstrument loan extension_option Customer	Jul. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	May. 31, 2015 USD ($)	Apr. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Mortgage Loans on Real Estate [Line Items]
Net carrying amounts of notes receivable		$ 153,351					$ 102,286
Number of cross collateralized loans | loan		3
Number of borrowers | Customer		1
Additional investment	$ 400
Nonperforming Financing Receivable
Mortgage Loans on Real Estate [Line Items]
Number of instruments held | debtinstrument		1
152 -154 Spring St
Mortgage Loans on Real Estate [Line Items]
Percentage of interests acquired				10.00%
Mezzanine Loan, 12.7% Loan, Due 2015
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		12.70%
First priority liens		$ 18,900
Net carrying amounts of notes receivable		$ 0	$ 8,000				8,000
First Mortgage Loan, 8.8% Loan, Due 2015
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		8.80%
Net carrying amounts of notes receivable		$ 7,500					7,500
Extension options | extension_option		1
Extension options, length of term		12 months
Zero Coupon Loan Due 2016
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		24.00%
First priority liens		$ 166,200
Net carrying amounts of notes receivable		$ 0				$ 5,600	4,986
First Mortgage Loan, 5.5% Loan Due 2016
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		5.50%
Net carrying amounts of notes receivable		$ 4,000					4,000
Extension options | extension_option		1
Extension options, length of term		6 months
First Mortgage Loan, 6% Loan Due On Demand
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		6.00%
Net carrying amounts of notes receivable		$ 15,000			$ 15,000		0
Extension options | extension_option		1
Extension options, length of term		12 months
Preferred Equity, 13.5% Loan, Due 2016
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		13.50%
Net carrying amounts of notes receivable		$ 4,000					4,000
Other Loan 17% Due 2016
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		17.00%
Net carrying amounts of notes receivable		$ 6,500		$ 6,500			0
Other Loan, 18%, Due 2017
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		18.00%
Net carrying amounts of notes receivable		$ 3,757					3,307
Preferred Equity, 8.1% Loan, Due 2017
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		8.10%
First priority liens		$ 20,855
Net carrying amounts of notes receivable		13,000					13,000
First Mortgage Loan LIBOR Plus 7.1% Due 2018
Mortgage Loans on Real Estate [Line Items]
Net carrying amounts of notes receivable		$ 26,000		26,000			0
Extension options | extension_option		1
Extension options, length of term		12 months
First Mortgage Loan LIBOR Plus 7.1% Due 2018 | LIBOR
Mortgage Loans on Real Estate [Line Items]
Loans receivable, basis spread on variable rate		7.10%
Zero Coupon Loan Due 2020
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		2.50%
Net carrying amounts of notes receivable		$ 30,046		29,800			0
Mezzanine Loan, Eighteen Percent, Due 2017 [Member]
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		15.00%
Net carrying amounts of notes receivable		$ 30,879					30,879
Other Loan, 15%, Loan Due 2020
Mortgage Loans on Real Estate [Line Items]
Net carrying amounts of notes receivable		$ 0					4,000
Other Loan, 15%, Loan Due 2020 | LIBOR
Mortgage Loans on Real Estate [Line Items]
Loans receivable, basis spread on variable rate		2.50%
Mezzanine Loan, 10% Due On Demand
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		10.00%
First priority liens		$ 87,477
Net carrying amounts of notes receivable		$ 0					7,983
First Mortgage Loan, 7.7% Loan Due 2015
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		7.70%
Net carrying amounts of notes receivable		$ 12,000					12,000
Individually Less Than 3 Percent, Variable Interest Rate
Mortgage Loans on Real Estate [Line Items]
Effective interest rate		11.60%
Net carrying amounts of notes receivable		$ 669		$ 1,900			2,631
Number of loans | loan		1
Threshold to disclose debt individually		3.00%
Carrying Amount
Mortgage Loans on Real Estate [Line Items]
Notes receivable and preferred equity investments, net		$ 153,351					$ 102,286