ACQUISITIONS AND DISPOSITIONS - Acquisitions (Details) $ in Thousands		6 Months Ended
	Jan. 18, 2018 USD ($) ft²	Jun. 30, 2019 acquistion	Dec. 31, 2017 USD ($)
Business Acquisition [Line Items]
Number of business acquisitions | acquistion		0
9460 Wilshire Boulevard in Los Angeles, California
Business Acquisition [Line Items]
Percent of ownership acquired	100.00%
Square Feet | ft²	91,750
Purchase Price | $	$ 132,000
Non-refundable deposit | $			$ 20,000
Asset acquisitions transaction costs | $	$ 48
9460 Wilshire Boulevard in Los Angeles, California - Office Space
Business Acquisition [Line Items]
Square Feet | ft²	68,866
9460 Wilshire Boulevard in Los Angeles, California - Retail Space
Business Acquisition [Line Items]
Square Feet | ft²	22,884