NET LOSS PER COMMON SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator:
Net loss	$ (9,778)	$ (3,650)
Dividends accumulated on convertible preferred stock	0	(1,804)
Net loss attributable to common shareholders	$ (9,778)	$ (5,454)
Denominator:
Weighted-average common shares outstanding	31,896	22,604
Net loss per share attributable to common shareholders (basic and diluted)	$ (0.31)	$ (0.24)
Aggregate number of common equivalent shares (related to options, warrants and preferred stock) that have been excluded from computations of diluted net loss per common share (in shares)	5,000	6,200