Segment And Geographic Information (Operating Segments) (Details) - USD ($) $ 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
Segment Reporting Information [Line Items]
Net sales	$ 657,050	$ 640,688	$ 660,591	$ 608,136	$ 666,036	$ 610,929	$ 619,611	$ 557,903	$ 620,043	$ 586,534	$ 580,513	$ 535,195	$ 2,566,465	$ 2,454,479	$ 2,322,285
Depreciation and amortization													51,839	48,672	55,139
Income from operations													58,538	76,826	76,860
Interest expense													(10,473)	(9,405)	(9,304)
Interest income													6,848	5,370	2,136
Other income (expense)													628	(1,786)	(282)
Income before income taxes													55,541	71,005	69,410
Capital expenditures													66,732	54,506	32,334
Total assets	1,899,783				2,109,304				2,008,925				1,899,783	2,109,304	2,008,925
Elimination Of Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Net sales													(68,766)	(84,820)	(79,373)
Corporate And Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Income from operations													(85,864)	(77,113)	(67,529)
Americas [Member]
Segment Reporting Information [Line Items]
Net sales													1,647,402	1,584,729	1,589,933
Depreciation and amortization													22,668	21,972	23,275
Income from operations													61,731	68,433	87,582
Capital expenditures													44,204	27,139	20,766
Total assets	852,776				812,187				871,577				852,776	812,187	871,577
Asia [Member]
Segment Reporting Information [Line Items]
Net sales													801,312	777,616	653,888
Depreciation and amortization													11,496	11,849	15,832
Income from operations													72,442	74,701	46,749
Capital expenditures													14,400	18,115	7,858
Total assets	540,094				674,783				637,376				540,094	674,783	637,376
Europe [Member]
Segment Reporting Information [Line Items]
Net sales													186,517	176,954	157,837
Depreciation and amortization													3,498	2,891	2,794
Income from operations													10,229	10,805	10,058
Capital expenditures													2,388	4,915	1,441
Total assets	113,165				470,786				393,973				113,165	470,786	393,973
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Total assets	$ 393,748				$ 151,548				$ 105,999				393,748	151,548	105,999
Corporate [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization													14,177	11,960	13,238
Capital expenditures													$ 5,740	$ 4,337	$ 2,269