CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Net sales	$ 191,272	$ 178,789	$ 566,793	$ 532,402
Cost of goods sold	118,852	103,045	343,557	325,382
Gross profit	72,420	75,744	223,236	207,020
Selling, general and administrative expenses	38,042	35,509	120,997	110,674
Technical, product engineering, and research expenses	9,232	10,675	29,640	33,387
Restructuring expenses, net	326	3,717	7,653	13,929
Operating income	24,820	25,843	64,946	49,030
Interest expense, net	3,681	2,671	9,610	8,049
Other (income)/expense, net	242	1,249	(2,103)	784
Income before income taxes	20,897	21,923	57,439	40,197
Income tax expense	7,488	12,243	20,613	20,398
Net income	13,409	9,680	36,826	19,799
Net (loss)/income attributable to the noncontrolling interest	340	22	(111)	100
Net income attributable to the Company	$ 13,069	$ 9,658	$ 36,937	$ 19,699
Earnings per share attributable to Company shareholders - Basic	$ 0.41	$ 0.30	$ 1.15	$ 0.62
Earnings per share attributable to Company shareholders - Diluted	$ 0.41	$ 0.30	$ 1.15	$ 0.62
Shares of the Company used in computing earnings per share:
Basic	32,104	32,012	32,079	31,965
Diluted	32,141	32,055	32,118	32,028
Dividends per share, Class A and Class B	$ 0.17	$ 0.17	$ 0.51	$ 0.5