Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	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, 2014	$ 188,560	$ 28	$ (12,148)	$ 372,319	$ (43)	$ (171,596)
Beginning Balance, Shares at Dec. 31, 2014		27,913,788
Beginning Balance, Treasury Shares at Dec. 31, 2014			(1,774,844)
Exercise of stock options	$ 4			4
Exercise of stock options, Shares	5,692	5,692
Stock-based compensation	$ 731			731
Restricted stock issued, net of restricted shares withheld for employee taxes	287			287
Restricted stock issued, net of restricted shares withheld for employee taxes, Shares		58,899
Common stock issued, net of shares withheld for employee taxes	224			224
Common stock issued, net of shares withheld for employee taxes, Shares		29,432
Unrealized gain on investments, net of tax	10				10
Net loss	(77,830)					(77,830)
Ending Balance at Dec. 31, 2015	$ 111,986	$ 28	$ (12,148)	373,565	(33)	(249,426)
Ending Balance, Shares at Dec. 31, 2015		28,007,811
Ending Balance, Treasury Shares at Dec. 31, 2015	(1,774,844)		(1,774,844)
Exercise of stock options
Stock-based compensation	527			527
Restricted stock issued, net of restricted shares withheld for employee taxes	559	$ 1		558
Restricted stock issued, net of restricted shares withheld for employee taxes, Shares		529,896
Common stock issued, net of shares withheld for employee taxes	253			253
Common stock issued, net of shares withheld for employee taxes, Shares		65,958
Foreign currency translation adjustments	(2)				(2)
Unrealized gain on investments, net of tax	5				5
Net loss	(62,879)					(62,879)
Ending Balance at Dec. 31, 2016	$ 50,449	$ 29	$ (12,148)	$ 374,903	$ (30)	$ (312,305)
Ending Balance, Shares at Dec. 31, 2016		28,603,665
Ending Balance, Treasury Shares at Dec. 31, 2016	(1,774,844)		(1,774,844)