AUGUST 2019 PUBLIC OFFERING AND PRIVATE PLACEMENT (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	12 Months Ended
	Aug. 16, 2019	Aug. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Shares issuable under warrants (in shares)		5,750,000
Proceeds from issuance of redeemable convertible preferred stock in a public offering, net			$ 53,800
Proceeds upon entering into private placement agreement		$ 11,200	11,152	$ 0
Total offering costs related to warrants and options			$ 2,992	$ 10
Series 1 redeemable convertible non-voting preferred stock
Class of Stock [Line Items]
Shares issuable per warrants (in shares)			10
Public Offering
Class of Stock [Line Items]
Shares issuable under warrants (in shares)	5,750,000
Price per share (in dollars per share)	$ 100.00
Public Offering | Series 1 redeemable convertible non-voting preferred stock
Class of Stock [Line Items]
Number of shares of common stock sold in offering (in shares)	575,000
Warrants exercise price (in dollars per share)	$ 130.00
Public Offering | Common Stock
Class of Stock [Line Items]
Shares issuable per warrants (in shares)	10
Warrants exercise price (in dollars per share)	$ 13.00
Public Offering | Common Stock | Minimum
Class of Stock [Line Items]
Warrants, limitations on ownership after exercise			9.99%
Public Offering | Common Stock | Maximum
Class of Stock [Line Items]
Warrants, limitations on ownership after exercise			19.99%
Private Placement | Series 2 redeemable convertible non-voting preferred stock
Class of Stock [Line Items]
Number of shares of common stock sold in offering (in shares)	350,000
Shares issuable under warrants (in shares)	2,800,000
Price per share (in dollars per share)	$ 100.00
Warrants exercise price (in dollars per share)	$ 10.00
Private Placement | Series 3 redeemable convertible non-voting preferred stock
Class of Stock [Line Items]
Number of shares of common stock sold in offering (in shares)	250,000
Private Placement | Preferred Stock
Class of Stock [Line Items]
Shares issuable under warrants (in shares)	875,000
Price per share (in dollars per share)	$ 140.00		$ 140.00
Warrants exercise price (in dollars per share)	$ 14.00