STOCKHOLDERS' EQUITY - Equity Financing (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2018
Equity [Abstract]
Proceeds from sale of stock	$ 27.8	$ 41.9	$ 9.0
Sale of stock, shares issued (in shares)	20.4	25.6	8.0
Number of warrants (in shares)	20.4		8.0
Stock and warrants price per share (in dollars per share)	$ 1.47
Exercise price per warrant (in dollars per share)	$ 1.47		$ 1.20
Warrants exercise period	1 year		5 years
Stock price per share (in dollars per share)		$ 1.80	$ 1.13
Warrant price per unit (in dollars per share)			$ 0.125