CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Common Stock in Treasury
Beginning Balance (in shares) at Dec. 31, 2015		16,588,118
Beginning Balance at Dec. 31, 2015	$ 327,644	$ 18	$ 206,996	$ 172,329	$ (19,861)	$ (31,838)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	11,107			11,107
Currency translation adjustment, net of income tax	(4,700)				(4,700)
Restricted stock issued and stock based compensation under incentive plans (in shares)		20,925
Restricted stock issued and stock based compensation under incentive plans	5,374		5,374
Stock options exercised, net of shares withheld for employee taxes (in shares)		71,748
Stock options exercised, net of shares withheld for employee taxes	674		674
Tax impact from restricted stock and stock options	(442)		(442)
Ending Balance (in shares) at Dec. 31, 2016		16,680,791
Ending Balance at Dec. 31, 2016	339,657	$ 18	212,602	183,436	(24,561)	(31,838)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(14,516)			(14,516)
Currency translation adjustment, net of income tax	16,739				16,739
Restricted stock issued and stock based compensation under incentive plans (in shares)		19,881
Restricted stock issued and stock based compensation under incentive plans	6,450		6,450
Stock options exercised, net of shares withheld for employee taxes (in shares)		86,994
Stock options exercised, net of shares withheld for employee taxes	3,284		3,284
Reissuance of treasury shares (in shares)		9,218
Reissuance of treasury shares	$ 310		281			29
Ending Balance (in shares) at Dec. 31, 2017	16,796,884	16,796,884
Ending Balance at Dec. 31, 2017	$ 352,066	$ 18	223,055	168,624	(7,822)	(31,809)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of the adoption of ASU 2016-09 | Accounting Standards Update 2014-09	142		438	(296)
Net income (loss)	4,930
Currency translation adjustment, net of income tax	(10,661)				(10,661)
Restricted stock issued and stock based compensation under incentive plans (in shares)		15,960
Restricted stock issued and stock based compensation under incentive plans	7,620		7,620
Stock options exercised, net of shares withheld for employee taxes (in shares)		382,957
Stock options exercised, net of shares withheld for employee taxes	17,028	$ 1	17,027
Reissuance of treasury shares (in shares)		57,210
Reissuance of treasury shares	$ 3,827					200
Ending Balance (in shares) at Dec. 31, 2018	17,253,011	17,253,011
Ending Balance at Dec. 31, 2018	$ 376,609	$ 19	$ 251,329	175,353	$ (18,483)	$ (31,609)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of the adoption of ASU 2016-09 | Accounting Standards Update 2014-09	$ 1,799			$ 1,799