RELATED PARTY TRANSACTIONS - Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Related Party Transaction [Line Items]
Payable as of	$ 9,608		$ 9,608		$ 8,626
Administrative fees, amount paid	102	$ 94	232	$ 185
Asset management fees
Related Party Transaction [Line Items]
Payable as of	9,600		9,600		8,500
Advisor and Dealer Manager
Related Party Transaction [Line Items]
Incurred	5,060	5,567	11,175	10,883
Payable as of	9,608		9,608		8,626
Advisor and Dealer Manager | Asset management fees
Related Party Transaction [Line Items]
Expenses	4,944	5,219	9,839	10,393
Payable as of	9,565		9,565		8,529
Advisor and Dealer Manager | Reimbursement of operating expenses
Related Party Transaction [Line Items]
Expenses	116	134	331	243
Payable as of	43		43		97
Advisor and Dealer Manager | Disposition fees
Related Party Transaction [Line Items]
Expenses	0	213	1,005	213
Payable as of	0		0		0
Advisor and Dealer Manager | Acquisition fee on development project
Related Party Transaction [Line Items]
Incurred	0	$ 1	0	$ 34
Payable as of	$ 0		$ 0		$ 0