STOCKHOLDERS' EQUITY (Details 2) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		12 Months Ended
	Nov. 30, 2017	Jan. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Nov. 21, 2012
Warrants - issued and outstanding
Exercise of warrants for cash (in shares)			585,729	313,756
Proceeds from issuance of common stock, net of issuance costs	$ 86.7	$ 66.8	$ 4.6	$ 2.1
Exercise price (in dollars per share)	$ 12.999	$ 5.599	$ 0.001
Number of warrants (in shares)	4,137,999	7,258,263	11,396,262
Number of warrants exercised (in shares)			52,825	289,789	1,037,330
Net exercise of warrants (in shares)			638,554	603,545	809,498
Common Stock
Warrants - issued and outstanding
Issuance of common stock, net of costs (in shares)	2,938,986	5,002,702	7,941,688		4,837,500
Share Price	$ 13.00	$ 5.60
Exercise of warrants for cash (in shares)			585,729	313,756
Net exercise of warrants (in shares)			52,825	289,789	809,498
Private Placement | January 11, 2017 Warrants
Warrants - issued and outstanding
Exercise price (in dollars per share)			$ 0.001
Number of warrants (in shares)			7,258,263
Private Placement | November 20, 2017 Warrants
Warrants - issued and outstanding
Exercise price (in dollars per share)						$ 0.001
Certain Holders
Warrants - issued and outstanding
Common stock, ownership percent, threshold			19.99%
Other Holders
Warrants - issued and outstanding
Common stock, ownership percent, threshold			9.99%