Revenue Recognition (Schedule of Consolidated Statement of Income) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net sales	$ 251,600	$ 251,900	$ 255,400	$ 223,600	$ 226,700	$ 222,100	$ 215,600	$ 199,300	$ 213,000	$ 191,300	$ 203,200	$ 172,300	$ 982,479	$ 863,717	$ 779,839
Cost of goods sold							15,800						632,730	567,434	478,555
Gross profit	87,900	92,400	91,700	77,700	77,500	79,600	63,200	76,000	77,500	72,600	78,500	72,700	349,749	296,283	301,284
Selling, general and administrative expenses													156,189	162,942	158,358
Technical and research expenses													40,582	41,174	40,306
Restructuring expenses, net													15,570	13,491	8,488
Operating income	37,400	40,800	42,200	17,000									137,408	78,676	94,132
Other expense, net													4,037	6,877	2,402
Income before income taxes													115,247	54,708	78,266
Income tax expense													32,228	22,123	25,454
Net income													83,019	32,585	52,812
Net income/(loss) attributable to the noncontrolling interest													128	(526)	79
Net income attributable to the Company	$ 17,600	$ 27,700	$ 29,900	$ 7,700	$ 5,900	$ 15,300	$ 1,100	$ 10,800	$ 15,700	$ 13,100	$ 10,400	$ 13,500	$ 82,891	$ 33,111	$ 52,733
Earnings per share attributable to Company shareholders - Basic	$ 0.54	$ 0.86	$ 0.93	$ 0.24	$ 0.19	$ 0.47	$ 0.03	$ 0.34	$ 0.49	$ 0.41	$ 0.32	$ 0.42	$ 2.57	$ 1.03	$ 1.64
Earnings per share attributable to Company shareholders - Diluted	$ 0.54	$ 0.86	$ 0.93	$ 0.24	$ 0.19	$ 0.47	$ 0.03	$ 0.34	$ 0.49	$ 0.41	$ 0.32	$ 0.42	$ 2.57	$ 1.03	$ 1.64
As reported [Member]
Net sales													$ 982,479
Cost of goods sold													632,730
Gross profit													349,749
Selling, general and administrative expenses													156,189
Technical and research expenses													40,582
Restructuring expenses, net													15,570
Operating income													137,408
Interest income													(2,118)
Interest expense													20,242
Other expense, net													(4,037)
Income before income taxes													115,247
Income tax expense													32,228
Net income													83,019
Net income/(loss) attributable to the noncontrolling interest													128
Net income attributable to the Company													$ 82,891
Earnings per share attributable to Company shareholders - Basic													$ 2.57
Earnings per share attributable to Company shareholders - Diluted													$ 2.57
Adjustments to reverse effects of ASC 606 [Member]
Net sales													$ 7,120
Cost of goods sold													10,433
Gross profit													(3,313)
Selling, general and administrative expenses													12
Technical and research expenses
Restructuring expenses, net
Operating income													(3,325)
Interest income
Interest expense
Other expense, net
Income before income taxes													(3,325)
Income tax expense													(877)
Net income													(2,448)
Net income/(loss) attributable to the noncontrolling interest													(129)
Net income attributable to the Company													$ (2,319)
Earnings per share attributable to Company shareholders - Basic													$ (0.07)
Earnings per share attributable to Company shareholders - Diluted													$ (0.07)
As adjusted to exclude adoption of ASC 606 [Member]
Net sales													$ 989,599
Cost of goods sold													643,163
Gross profit													346,436
Selling, general and administrative expenses													156,201
Technical and research expenses													40,582
Restructuring expenses, net													15,570
Operating income													134,083
Interest income													(2,118)
Interest expense													20,242
Other expense, net													(4,037)
Income before income taxes													111,922
Income tax expense													31,351
Net income													80,571
Net income/(loss) attributable to the noncontrolling interest													(1)
Net income attributable to the Company													$ 80,572
Earnings per share attributable to Company shareholders - Basic													$ 2.50
Earnings per share attributable to Company shareholders - Diluted													$ 2.50