STOCKHOLDERS' EQUITY (DEFICIT) - Equity Financing (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended				5 Months Ended	9 Months Ended
	Nov. 30, 2019	Jun. 30, 2019	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2020	Sep. 30, 2020	Jun. 21, 2020
Class of Stock [Line Items]
Proceeds from sale of stock		$ 27.8
Sale of stock, shares issued (in shares)		20,400,000
Issuance of common stock, issuance costs			$ 0.3	$ 0.1	$ 0.1	$ 2.2		$ 0.5
Number of warrants issued (in shares)		20,400,000				20,400,000
Combined purchase price (in dollars per share)		$ 1.47				$ 1.47
Exercise price per warrant (in dollars per share)		$ 1.47				$ 1.47
Warrants exercise period									1 year
ATM Facility
Class of Stock [Line Items]
Aggregate sales price	$ 35.0
Commission fixed rate	3.00%
Legal, accounting and printing costs							$ 0.2
Proceeds from sale of stock			$ 8.2					$ 16.2
Sale of stock, shares issued (in shares)			7,000,000.0					16,800,000
Stock price per share (in dollars per share)			$ 1.21					$ 0.99