Segment And Geographic Information (Schedule Of Geographic Net Sales And Long-Lived Assets) (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]
Geographic 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
Long-lived assets	301,589				282,480				268,070				301,589	282,480	268,070
United States [Member]
Segment Reporting Information [Line Items]
Geographic net sales													1,741,321	1,650,791	1,624,050
Long-lived assets	190,056				167,858				167,367				190,056	167,858	167,367
Asia [Member]
Segment Reporting Information [Line Items]
Geographic net sales													423,245	432,530	336,022
Long-lived assets	79,051				77,750				67,998				79,051	77,750	67,998
Europe [Member]
Segment Reporting Information [Line Items]
Geographic net sales													299,676	291,006	254,272
Long-lived assets	9,537				11,042				8,415				9,537	11,042	8,415
Other Foreign [Member]
Segment Reporting Information [Line Items]
Geographic net sales													102,223	80,152	107,941
Long-lived assets	$ 22,945				$ 25,830				$ 24,290				$ 22,945	$ 25,830	$ 24,290