Segment And Geographic Information (Operating Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 640,688	$ 610,929	$ 1,909,415	$ 1,788,443
Depreciation and amortization	14,560	12,274	39,643	36,591
Income from operations	10,957	20,903	43,273	54,916
Interest expense	(3,822)	(2,324)	(8,543)	(6,861)
Interest income	1,619	1,334	5,197	3,621
Other Non operating Income Expense	1,139	(394)	827	(1,305)
Income before income taxes	9,893	19,519	40,754	50,371
Capital expenditures	14,570	11,357	52,933	37,736
Total assets	1,940,771		1,940,771		$ 2,109,304
Elimination Of Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Net sales	(16,656)	(20,521)	(50,893)	(67,199)
Corporate And Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Income from operations	(19,834)	(18,171)	(59,450)	(54,651)
Americas [Member]
Segment Reporting Information [Line Items]
Net sales	404,137	379,417	1,217,200	1,146,171
Depreciation and amortization	5,746	5,679	17,171	16,599
Income from operations	9,586	15,046	41,845	46,823
Capital expenditures	8,975	8,548	34,369	17,584
Total assets	848,998		848,998		812,187
Asia [Member]
Segment Reporting Information [Line Items]
Net sales	210,153	208,207	602,903	581,991
Depreciation and amortization	2,967	2,882	8,660	9,021
Income from operations	18,963	21,477	53,441	55,314
Capital expenditures	3,898	1,696	12,548	12,820
Total assets	548,571		548,571		674,783
Europe [Member]
Segment Reporting Information [Line Items]
Net sales	43,054	43,826	140,205	127,480
Depreciation and amortization	860	705	2,644	2,041
Income from operations	2,242	2,551	7,437	7,430
Capital expenditures	651	638	2,303	4,018
Total assets	144,352		144,352		470,786
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Total assets	398,850		398,850		$ 151,548
Corporate [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization	4,987	3,008	11,168	8,930
Capital expenditures	$ 1,046	$ 475	$ 3,713	$ 3,314