Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Treasury Stock [Member]	Additional paid-in Capital [Member]	Accum Other Comp Inc. [Member]	Accum deficit [Member]
Beginning Balance at Dec. 31, 2011	$ 228,231	$ 24	$ (12,148)	$ 332,119	$ (50)	$ (91,714)
Beginning Balance, Treasury Shares at Dec. 31, 2011			(1,774,844)
Beginning Balance, Shares at Dec. 31, 2011		24,289,723
Exercise of stock options	73	1		72
Exercise of stock options, Shares	17,885	17,884
Net exercise of stock warrants	0	0	0	0	0	0
Net exercise of stock warrants, Shares		2,188
Stock-based compensation	1,801			1,801
Excess tax benefit of stock based compensation	160			160
Stock issued to Board of Directors	162			162
Stock issued to Board of Directors, Shares		17,345
Foreign currency translation adjustments	(8)				(8)
Unrealized (gain) loss on investments, net of tax	505				505
Net loss	(5,538)					(5,538)
Ending Balance at Dec. 31, 2012	225,386	25	(12,148)	334,314	447	(97,252)
Ending Balance, Treasury Shares at Dec. 31, 2012			(1,774,844)
Ending Balance, Shares at Dec. 31, 2012		24,327,140
Exercise of stock options	140			140
Exercise of stock options, Shares	27,930	27,930
Stock-based compensation	1,246			1,246
Excess tax benefit of stock based compensation	(114)			(114)
Restricted stock issued	292			292
Restricted stock issued, shares		73,707
Stock issued to Board of Directors	57			57
Stock issued to Board of Directors, Shares		4,746
Foreign currency translation adjustments	(2)				(2)
Unrealized (gain) loss on investments, net of tax	(863)				(863)
Net loss	(30,351)					(30,351)
Ending Balance at Dec. 31, 2013	195,791	25	(12,148)	335,935	(418)	(127,603)
Ending Balance, Treasury Shares at Dec. 31, 2013	(1,774,844)		(1,774,844)
Ending Balance, Shares at Dec. 31, 2013		24,433,523
Exercise of stock options	256			256
Exercise of stock options, Shares	47,654	47,654
Stock-based compensation	960			960
Restricted stock issued, net of unvested restricted stock cancelled	448			448
Restricted stock issued, net of unvested restricted stock cancelled, Shares		7,013
Common stock issued, net of shares withheld for employee taxes	(55)			(55)
Common stock issued, net of shares withheld for employee taxes, Shares		3,098
Common stock issued, net of issuance costs	34,778	3		34,775
Common stock issued, net of issuance costs, Shares		3,422,500
Reclassification of unrealized gain included in net loss	388				388
Foreign currency translation adjustments	(4)				(4)
Unrealized (gain) loss on investments, net of tax	(9)				(9)
Net loss	(43,993)					(43,993)
Ending Balance at Dec. 31, 2014	$ 188,560	$ 28	$ (12,148)	$ 372,319	$ (43)	$ (171,596)
Ending Balance, Treasury Shares at Dec. 31, 2014	(1,774,844)		(1,774,844)
Ending Balance, Shares at Dec. 31, 2014		27,913,788