STOCKHOLDERS' (DEFICIT) EQUITY - Equity Financing (Details) - USD ($)		1 Months Ended				12 Months Ended
	Nov. 01, 2017	Nov. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Sale of stock, floor price per share (in dollars per share)		$ 1.00
Stock price per share (in dollars per share)				$ 1.80	$ 1.13
Commission fixed rate		3.00%
Legal, accounting and printing costs						$ 200,000
Proceeds from sale of stock	$ 7,000,000		$ 27,800,000	$ 41,900,000	$ 9,000,000
Sale of stock, shares issued (in shares)	5,500,000		20,400,000	25,600,000	8,000,000
Number of warrants (in shares)			20,400,000		8,000,000
Stock and warrants price per share (in dollars per share)			$ 1.47
Exercise price per warrant (in dollars per share)	$ 0.80		$ 1.47		$ 1.20
Warrants exercise period			1 year		5 years
Warrant price per unit (in dollars per share)	0.01				$ 0.125
Common Stock
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Stock price per share (in dollars per share)	$ 0.80
Number of warrants (in shares)	1
Pre-Funded Warrant
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Number of warrants (in shares)	4,500,000
Warrant price per unit (in dollars per share)	$ 0.79
Common Warrants
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Number of warrants (in shares)	1
Expiration period	5 years
ATM Facility
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Aggregate sales price		$ 35,000,000.0
Proceeds from sale of stock						$ 1,900,000
Sale of stock, shares issued (in shares)						2,100,000