Consolidated Statement of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Accumulated Deficit	Accumulated Other Comprehensive Income (loss)
Beginning balance, shares at Dec. 31, 2014		36,532,000
Beginning balance at Dec. 31, 2014	$ 77,776	$ 334,024	$ (256,671)	$ 423
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued pursuant to benefit plans, shares		205,000
Shares issued pursuant to benefit plans	331	$ 331
Stock based compensation associated with employee benefit plans	3,952	$ 3,952
Vesting of restricted stock units, shares		279,000
Restricted share forfeitures for tax settlements, shares		(57,000)
Restricted share forfeitures for tax settlements	(142)	$ (142)
Net adjustment for fair value of hedge derivatives, net of taxes	(67)			(67)
Translation adjustments	(1,255)			(1,255)
Net income (loss)	(14,678)			0
Ending balance, shares at Dec. 31, 2015		36,959,000
Ending balance at Dec. 31, 2015	65,917	$ 338,165	(271,349)	(899)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued pursuant to benefit plans, shares		393,000
Shares issued pursuant to benefit plans	1,040	$ 1,040
Stock based compensation associated with employee benefit plans	3,797	$ 3,797
Vesting of restricted stock units, shares		1,799,000
Restricted share forfeitures for tax settlements, shares		(630,000)
Restricted share forfeitures for tax settlements	(3,287)	$ (3,287)
Net adjustment for fair value of hedge derivatives, net of taxes	292			292
Translation adjustments	(952)			(952)
Net income (loss)	$ (10,251)
Ending balance, shares at Dec. 31, 2016	36,959,000	38,521,000
Ending balance at Dec. 31, 2016	$ 56,556	$ 339,715	(281,600)	(1,559)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued pursuant to benefit plans, shares	319,000	283,000
Shares issued pursuant to benefit plans	$ 516	$ 516
Stock based compensation associated with employee benefit plans	2,192	$ 2,192
Vesting of restricted stock units, shares		530,000
Restricted share forfeitures for tax settlements, shares		(54,000)
Restricted share forfeitures for tax settlements	(204)	$ (204)
Net adjustment for fair value of hedge derivatives, net of taxes	350			350
Translation adjustments	1,722			1,722
intellectual property tax adjustment	(1,978)			(1,978)
Net income (loss)	$ (52,604)
Ending balance, shares at Dec. 31, 2017	38,521,000	39,280,000
Ending balance at Dec. 31, 2017	$ 6,550	$ 342,219	$ (336,182)	$ 513