REDEEMABLE PREFERRED STOCK - Narrative (Details) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Class of Stock [Line Items]
Gross proceeds from issuance of preferred stock and warrants	$ 147,864,000
Issuance offering costs for preferred stock and warrants	12,043,000
Non-issuance offering costs for preferred stock and warrants	$ 7,063,000
Series A Preferred Warrants
Class of Stock [Line Items]
Warrants issued (in shares)	4,603,287
Gross proceeds from issuance of preferred stock and warrants	$ 761,000
Issuance offering costs for preferred stock and warrants	142,000
Reclassification to deferred rent receivable and charges	$ 5,000
Warrants outstanding (in shares)	4,603,287
Series A Preferred Stock
Class of Stock [Line Items]
Gross proceeds from issuance of preferred stock and warrants	$ 146,651,000
Issuance offering costs for preferred stock and warrants	11,889,000
Reclassification to deferred rent receivable and charges	$ 1,152,000
Preferred stock, shares outstanding (in shares)	5,915,816
Preferred stock, shares redeemed (in shares)	87,238
Series A Preferred Stock | Preferred Stock, Shares Issued, One
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)	5,896,536
Series A Preferred Stock | Preferred Stock, Shares Issued, Two
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)	106,518
Net proceeds from issuance of Series Preferred Stock	$ 0
Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)	18,737		0
Gross proceeds from issuance of preferred stock and warrants	$ 452,000
Net proceeds from issuance of Series Preferred Stock	446,000	$ 0
Issuance offering costs for preferred stock and warrants	12,000
Reclassification to deferred rent receivable and charges	$ 4,000
Preferred stock, shares outstanding (in shares)	18,737	0	0
Preferred stock, shares redeemed (in shares)	0
Series A Preferred Unit
Class of Stock [Line Items]
Number of securities called by warrants or rights (in shares)	1,194,159