CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Net sales	$ 229,981	$ 199,277
Cost of goods sold	148,330	123,249
Gross profit	81,651	76,028
Selling, general, and administrative expenses	41,930	40,407
Technical and research expenses	10,317	10,262
Restructuring expenses, net	8,573	2,681
Operating income	20,831	22,678
Interest expense, net	4,288	4,328
Other expense, net	1,452	826
Income before income taxes	15,091	17,524
Income tax expense	4,609	6,550
Net income	10,482	10,974
Net income attributable to the noncontrolling interest	237	135
Net income attributable to the Company	$ 10,245	$ 10,839
Earnings per share attributable to Company shareholders - Basic	$ 0.32	$ 0.34
Earnings per share attributable to Company shareholders - Diluted	$ 0.32	$ 0.34
Shares of the Company used in computing earnings per share:
Basic	32,220	32,128
Diluted	32,236	32,164
Dividends declared per share, Class A and Class B	$ 0.17	$ 0.17