Interim Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - 9 months ended Sep. 30, 2016 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Loss
Balance at Dec. 31, 2015	$ 360,469	$ 1,139	$ 96,778	$ (426)	$ 299,057	$ (36,079)
Balance (shares) at Dec. 31, 2015		11,350
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	32,457				32,457
Translation adjustment	(5,283)					(5,283)
Net actuarial gain arising during period	504					504
Tax effect of non-qualified stock options	141		141
Stock-based compensation	1,075		1,075
Exercise of stock options	1,254	$ 7	1,247
Exercise of stock options (shares)		68
Repurchased shares	(19)		(19)
Dividends paid ($.27 per share)	(3,082)				(3,082)
Balance at Sep. 30, 2016	$ 387,516	$ 1,146	$ 99,222	$ (426)	$ 328,432	$ (40,858)
Balance (shares) at Sep. 30, 2016		11,418