UNSECURED NOTES PAYABLE (Details) - USD ($)	1 Months Ended	3 Months Ended
	Jan. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Mortgage and other notes payable, net of unamortized loan costs of $9,884 and $10,567, respectively and unamortized premiums of $1,726 and $1,364, respectively		$ 955,003,000	$ 1,050,051,000
Line of Credit | Unsecured Credit Facility
Debt Instrument [Line Items]
Amount repaid on subscription line		20,800,000
Debt instrument face amount	$ 50,000,000
Fund IV | Line of Credit
Debt Instrument [Line Items]
Amount borrowed on unsecured credit facility		5,600,000
Long-term line of credit		40,100,000
Fund IV | Line of Credit | Subscription Line
Debt Instrument [Line Items]
Amount repaid on subscription line		9,200,000
Fund IV | Line of Credit | Subscription Line | Line of Credit
Debt Instrument [Line Items]
Mortgage and other notes payable, net of unamortized loan costs of $9,884 and $10,567, respectively and unamortized premiums of $1,726 and $1,364, respectively		82,700,000
Fund II | Line of Credit
Debt Instrument [Line Items]
Long-term line of credit		20,000,000
Fund II | Line of Credit | Subscription Line | Line of Credit
Debt Instrument [Line Items]
Amount borrowed on unsecured credit facility		$ 7,500,000
LIBOR | Line of Credit | Unsecured Credit Facility
Debt Instrument [Line Items]
Basis spread on variable rate	1.30%