Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net sales	$ 1,054,132	$ 982,479	$ 863,717
Cost of goods sold	656,431	632,730	567,434
Gross profit	397,701	349,749	296,283
Selling, general and administrative expenses	163,651	156,189	162,942
Technical and research expenses	37,569	40,582	41,174
Restructuring expenses, net	2,905	15,570	13,491
Operating income	193,576	137,408	78,676
Interest income	(2,729)	(2,118)	(1,511)
Interest expense	19,650	20,242	18,602
Other (income) / expense, net	(1,557)	4,037	6,877
Income before income taxes	178,212	115,247	54,708
Income tax expense	44,829	32,228	22,123
Net income	133,383	83,019	32,585
Net income/(loss) attributable to the noncontrolling interest	985	128	(526)
Net income attributable to the Company	$ 132,398	$ 82,891	$ 33,111
Earnings per share attributable to Company shareholders - Basic	$ 4.10	$ 2.57	$ 1.03
Earnings per share attributable to Company shareholders - Diluted	4.10	2.57	1.03
Dividends declared per share, Class A and Class B	$ 0.73	$ 0.69	$ 0.68