Consolidated Statements Of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
BALANCE - value at Dec. 31, 2014	$ 255,963	$ 6		$ 278,166	$ (21,475)	$ (734)
BALANCE - shares at Dec. 31, 2014		60,170
Share-based compensation, Value	4,040			4,040
Share-based compensation, Shares		154
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(267)			(267)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		115
Exercise of stock options and purchases from employee stock plan, Value	1,365			1,365
Exercise of stock options and purchases from employee stock plan, Shares		270
Excess income tax benefit from share-based compensation	(57)			(57)
Purchase of treasury stock, value	(1,433)		$ (1,433)
Purchase of treasury stock, shares			(278)
Net loss	(6,189)				(6,189)
Other comprehensive income (loss)—net of tax	(1,249)					(1,249)
BALANCE - value at Dec. 31, 2015	252,173	$ 6	$ (1,433)	283,247	(27,664)	(1,983)
BALANCE - shares at Dec. 31, 2015		60,709	(278)
Share-based compensation, Value	2,455			2,455
Share-based compensation, Shares		148
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(171)			(171)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		74
Exercise of stock options and purchases from employee stock plan, Value	905			905
Exercise of stock options and purchases from employee stock plan, Shares		309
Excess income tax benefit from share-based compensation	(133)			(133)
Net loss	(8,177)				(8,177)
Other comprehensive income (loss)—net of tax	838					838
BALANCE - value at Dec. 31, 2016	247,890	$ 6	$ (1,433)	286,303	(35,841)	(1,145)
BALANCE - shares at Dec. 31, 2016		61,240	(278)
Share-based compensation, Value	2,963			2,963
Share-based compensation, Shares		248
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(328)			(328)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		147
Exercise of stock options and purchases from employee stock plan, Value	$ 883			883
Exercise of stock options and purchases from employee stock plan, Shares	4	262
Net loss	$ (31,260)				(31,260)
Other comprehensive income (loss)—net of tax	1,148					1,148
BALANCE - value at Dec. 31, 2017	$ 221,296	$ 6	$ (1,433)	$ 289,821	$ (67,101)	$ 3
BALANCE - shares at Dec. 31, 2017		61,897	(278)