Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total
Balance at Dec. 31, 2013	$ 5		$ 267,767	$ 195	$ (110,935)	$ 157,032
Balance (in shares) at Dec. 31, 2013	49,998,274
Increase (Decrease) in Stockholders' Equity
Exercise of stock options awards			767			767
Exercise of stock options awards (in shares)	773,411
Stock-based compensation expense			4,607			4,607
Common stock issued for settlement of restricted stock units net of 173,707, 210,029 and 274,980 shares withheld to satisfy income tax withholding obligations for the years 2014, 2015 and 2016 respectively			953			953
Common stock issued for settlement of restricted stock units net of 173,707, 210,029 and 210,029 shares withheld to satisfy income tax withholding obligations for the years 2014, 2015 and 2016 respectively (in shares)	334,569
Net loss					(23,489)	(23,489)
Foreign currency translation adjustment				(97)		(97)
Balance at Dec. 31, 2014	$ 5		274,094	98	(134,424)	139,773
Balance (in shares) at Dec. 31, 2014	51,106,254
Increase (Decrease) in Stockholders' Equity
Exercise of stock options awards			108			108
Exercise of stock options awards (in shares)	165,292
Stock-based compensation expense			4,002			4,002
Common stock issued for settlement of restricted stock units net of 173,707, 210,029 and 274,980 shares withheld to satisfy income tax withholding obligations for the years 2014, 2015 and 2016 respectively			220			220
Common stock issued for settlement of restricted stock units net of 173,707, 210,029 and 210,029 shares withheld to satisfy income tax withholding obligations for the years 2014, 2015 and 2016 respectively (in shares)	573,690
Common stock issuance in connection with employee stock purchase plan			712			712
Common stock issuance in connection with employee stock purchase plan (in shares)	369,148
Net loss					(43,230)	(43,230)
Foreign currency translation adjustment				(153)		(153)
Balance at Dec. 31, 2015	$ 5		279,136	(55)	(177,654)	101,432
Balance (in shares) at Dec. 31, 2015	52,214,384
Increase (Decrease) in Stockholders' Equity
Exercise of stock options awards			161			$ 161
Exercise of stock options awards (in shares)	167,367					167,367
Stock-based compensation expense			3,895			$ 3,895
Common stock issued for settlement of restricted stock units net of 173,707, 210,029 and 274,980 shares withheld to satisfy income tax withholding obligations for the years 2014, 2015 and 2016 respectively			(205)			(205)
Common stock issued for settlement of restricted stock units net of 173,707, 210,029 and 210,029 shares withheld to satisfy income tax withholding obligations for the years 2014, 2015 and 2016 respectively (in shares)	560,922
Common stock issuance in connection with employee stock purchase plan			499			499
Common stock issuance in connection with employee stock purchase plan (in shares)	350,283
Treasury stock - repurchase of stock		$ (6,037)				$ (6,037)
Treasury stock - repurchase of stock (in shares)	(2,861,632)					(2,861,632)
Net loss					(20,947)	$ (20,947)
Foreign currency translation adjustment				(276)		(276)
Balance at Dec. 31, 2016	$ 5	$ (6,037)	$ 283,486	$ (331)	$ (198,601)	$ 78,522
Balance (in shares) at Dec. 31, 2016	50,431,324