Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2013	Jun. 30, 2012	Jun. 29, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Number of reportable segments			5
Product Sales	$ 596,070	$ 586,667	$ 1,148,344	$ 1,123,294
Royalty Revenues	1,595	1,532	3,575	3,452
Total Revenue	597,665	588,199	1,151,919	1,126,746
Gross Margin	142,857	147,619	279,591	284,328
Gain on Sale of Property	0	12,153	0	12,153
Executive compensation credit (charge)	1,778	0	1,778	0
Operating Income (Loss)	51,890	72,883	97,495	123,228
MOSFETS Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	115,484	111,326	216,330	206,027
Royalty Revenues	79	37	121	174
Total Revenue	115,563	111,363	216,451	206,201
Gross Margin	16,466	18,709	29,366	29,326
Segment Operating Income	5,682	8,676	8,515	9,999
Diodes Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	140,623	136,008	265,735	256,142
Royalty Revenues	0	0	0	0
Total Revenue	140,623	136,008	265,735	256,142
Gross Margin	31,427	28,676	58,688	53,730
Segment Operating Income	25,339	22,682	46,728	42,041
Optoelectronic Components Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	58,397	58,083	114,623	108,695
Royalty Revenues	0	0	0	27
Total Revenue	58,397	58,083	114,623	108,722
Gross Margin	19,151	18,605	38,925	35,899
Segment Operating Income	15,558	15,192	31,767	29,237
Resistors And Inductors Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	169,817	164,903	333,745	322,157
Royalty Revenues	1,516	1,495	3,454	3,251
Total Revenue	171,333	166,398	337,199	325,408
Gross Margin	54,345	55,073	106,946	109,332
Segment Operating Income	45,540	46,688	89,740	93,200
Capacitors Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	111,749	116,347	217,911	230,273
Royalty Revenues	0	0	0	0
Total Revenue	111,749	116,347	217,911	230,273
Gross Margin	21,468	26,556	45,666	56,041
Segment Operating Income	15,585	20,951	34,041	44,868
Unallocated Amount to Segment [Member]
Segment Reporting Information [Line Items]
Segment Operating Income	$ (57,592)	$ (53,459)	$ (115,074)	$ (108,270)