AUGUST 2019 PUBLIC OFFERING AND PRIVATE PLACEMENT - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		6 Months Ended
	Aug. 16, 2019	Jun. 30, 2020
Class of Stock [Line Items]
Proceeds from issuance of redeemable convertible preferred stock in a public offering, net		$ 53.8
Proceeds upon entering into private placement agreement		11.2
Total offering costs related to warrants and options		$ 3.0
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 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 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
Warrants exercise price (in dollars per share)	$ 14.00