FAIR VALUE DISCLOSURES - Summary of Face Values, Carrying Amounts and Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans receivable, Face Value	$ 259,175	$ 234,359
Preferred equity investment, Face Value	27,284	16,125
Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities, Face Value	700,000	700,000
Mortgage indebtedness [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities, Face Value	168,608	124,022
Carrying Amount [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans receivable	259,826	235,176
Preferred equity investments	27,622	16,407
Carrying Amount [Member] | Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	699,349	699,272
Carrying Amount [Member] | Mortgage indebtedness [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	168,608	124,022
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans receivable	264,260	234,227
Preferred equity investments	29,689	17,115
Fair Value [Member] | Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	722,750	723,625
Fair Value [Member] | Mortgage indebtedness [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	$ 158,792	$ 122,131