CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Series A Convertible Preferred Stock Preferred Stock	Series C Convertible Preferred Stock Preferred Stock
Balance (in shares) at Dec. 31, 2014		52,819,787				0	0
Balance at Dec. 31, 2014	$ 39,134	$ 548	$ 78,172	$ (39,586)	$ 0	$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock to consultant (in shares)		5,000
Issuance of stock to consultant	31		31
Stock based compensation expense	2,273		2,273
Stock warrants exercised (in shares)		67,636
Stock warrants exercised	82		82
Stock options exercised (in shares)		75,766
Stock options exercised	83	$ 1	82
Issuance of restricted stock (in shares)		32,500
Issuance of restricted stock	346		346
Reclassification of derivative liability to equity	18,256		18,256
Recovery from stockholder, net	19		19
Costs related to stock issuance	3		3
Cumulative translation adjustment	(130)				(130)
Net income (loss)	6,668			6,668
Balance (in shares) at Dec. 31, 2015		53,000,689				0	0
Balance at Dec. 31, 2015	66,759	$ 549	99,258	(32,918)	(130)	$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock to consultant (in shares)		25,000
Issuance of stock to consultant	189		189
Stock based compensation expense	3,090		3,090
Stock options exercised (in shares)		61,834
Stock options exercised	96	$ 1	95
Issuance of restricted stock (in shares)		60,918
Issuance of restricted stock	1	$ 1
Reclassification of derivative liability to equity	0
Recovery from stockholder, net	(36)		(36)
Costs related to stock issuance	28		28
Cumulative translation adjustment	(1,475)				(1,475)
Net income (loss)	(11,985)			(11,985)
Balance (in shares) at Dec. 31, 2016		53,148,441				0	0
Balance at Dec. 31, 2016	56,667	$ 551	102,624	(44,903)	(1,605)	$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation expense	3,422		3,422
Stock options exercised (in shares)		171,566
Stock options exercised	269	$ 2	267
Issuance of restricted stock (in shares)		80,274
Issuance of restricted stock		$ 1	(1)
Reclassification of derivative liability to equity	0
Cumulative translation adjustment	(414)				(414)
Net income (loss)	(15,191)			(15,191)
Balance (in shares) at Dec. 31, 2017		53,400,281				0	0
Balance at Dec. 31, 2017	$ 44,753	$ 554	$ 106,312	$ (60,094)	$ (2,019)	$ 0	$ 0