REDEEMABLE PREFERRED STOCK - Series A Preferred Stock Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 31, 2020
Class of Stock [Line Items]
Redeemable preferred stock dividend	$ 377,000	$ 0	$ 0
Reclassification of Series A Preferred Stock to permanent equity	$ 35,483,000	35,649,000	27,887,000
Registration Statement
Class of Stock [Line Items]
Warrant right to purchase a share of common stock (in shares)	0.25			0.25
Series A Preferred Stock
Class of Stock [Line Items]
Redeemable preferred stock dividend	$ 377,000	$ 0	$ 0
Reclassification of Series A Preferred Stock to permanent equity	$ 100,400,000
Series A Preferred Stock | Registration Statement
Class of Stock [Line Items]
Preferred stock, par value (in usd per share)	$ 0.001
Preferred stock, stated value (in usd per share)	$ 25.00