Segment And Geographic Information (Operating Segments) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	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, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Sales	$ 508,444	$ 555,229	$ 601,602	$ 602,820	$ 657,050	$ 640,688	$ 660,591	$ 608,136	$ 666,036	$ 610,929	$ 619,611	$ 557,903	$ 2,268,095	$ 2,566,465	$ 2,454,479
Depreciation and amortization													48,427	51,839	48,672
Income from operations													28,545	58,538	76,826
Interest expense													(6,664)	(10,473)	(9,405)
Interest income													3,829	6,848	5,370
Other income (expense)													1,559	628	(1,786)
Income before income taxes													27,269	55,541	71,005
Capital expenditures													35,118	66,732	54,506
Total assets	1,759,874				1,899,783				2,109,304				1,759,874	1,899,783	2,109,304
Elimination Of Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Sales													(78,714)	(68,766)	(84,820)
Corporate And Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Income from operations													(82,049)	(85,864)	(77,113)
Americas [Member]
Segment Reporting Information [Line Items]
Sales													1,428,795	1,647,402	1,584,729
Depreciation and amortization													21,784	22,668	21,972
Income from operations													55,749	61,731	68,433
Capital expenditures													15,822	44,204	27,139
Total assets	792,180				852,776				812,187				792,180	852,776	812,187
Asia [Member]
Segment Reporting Information [Line Items]
Sales													741,630	801,312	777,616
Depreciation and amortization													11,108	11,496	11,849
Income from operations													47,862	72,442	74,701
Capital expenditures													9,493	14,400	18,115
Total assets	533,508				540,094				674,783				533,508	540,094	674,783
Europe [Member]
Segment Reporting Information [Line Items]
Sales													176,384	186,517	176,954
Depreciation and amortization													3,035	3,498	2,891
Income from operations													6,983	10,229	10,805
Capital expenditures													3,702	2,388	4,915
Total assets	139,977				113,165				470,786				139,977	113,165	470,786
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Total assets	$ 294,209				$ 393,748				$ 151,548				294,209	393,748	151,548
Corporate [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization													12,500	14,177	11,960
Capital expenditures													$ 6,101	$ 5,740	$ 4,337