FAIR VALUE DISCLOSURES - Summary of Face Values, Carrying Amounts and Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans receivable, Face Value	$ 255,117	$ 234,359
Preferred equity investment, Face Value	22,332	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	142,252	124,022
Carrying Amount [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans receivable	255,836	235,176
Preferred equity investments	22,671	16,407
Carrying Amount [Member] | Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	699,323	699,272
Carrying Amount [Member] | Mortgage indebtedness [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	142,252	124,022
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans receivable	259,771	234,227
Preferred equity investments	24,341	17,115
Fair Value [Member] | Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	725,000	723,625
Fair Value [Member] | Mortgage indebtedness [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial liabilities	$ 141,962	$ 122,131