Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jul. 02, 2011	Jun. 30, 2012	Jul. 02, 2011
Segment Reporting Information [Line Items]
Product Sales	$ 586,667	$ 708,279	$ 1,123,294	$ 1,402,074
Royalty Revenues	1,532	1,559	3,452	2,915
Total Revenue	588,199	709,838	1,126,746	1,404,989
Gross Margin	147,619	212,190	284,328	426,853
Gain on Sale of Property	12,153	0	12,153	0
Operating Income (Loss)	72,883	115,505	123,228	237,703
MOSFETS Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	111,326	153,180	206,027	296,081
Royalty Revenues	37	65	174	162
Total Revenue	111,363	153,245	206,201	296,243
Gross Margin	18,709	42,811	29,326	82,250
Operating Income	8,676	32,522	9,999	61,932
Diodes Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	136,008	169,613	256,142	329,030
Royalty Revenues	0	0	0	0
Total Revenue	136,008	169,613	256,142	329,030
Gross Margin	28,676	43,699	53,730	82,839
Operating Income	22,682	37,208	42,041	70,008
Optoelectronic Components Segments [Member]
Segment Reporting Information [Line Items]
Product Sales	58,083	63,761	108,695	121,467
Royalty Revenues	0	0	27	42
Total Revenue	58,083	63,761	108,722	121,509
Gross Margin	18,605	21,961	35,899	41,909
Operating Income	15,192	18,330	29,237	34,687
Resistors And Inductors Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	164,903	167,430	322,157	339,349
Royalty Revenues	1,495	1,494	3,251	2,711
Total Revenue	166,398	168,924	325,408	342,060
Gross Margin	55,073	58,956	109,332	120,114
Operating Income	46,688	51,757	93,200	105,861
Capacitors Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	116,347	154,295	230,273	316,147
Royalty Revenues	0	0	0	0
Total Revenue	116,347	154,295	230,273	316,147
Gross Margin	26,556	44,763	56,041	99,741
Operating Income	20,951	38,584	44,868	86,917
Unallocated Amount to Segment [Member]
Segment Reporting Information [Line Items]
Operating Income	(53,459)	(59,007)	(108,270)	(117,813)
Executive Compensation Charge [Member]
Segment Reporting Information [Line Items]
Operating Income		$ (3,889)		$ (3,889)