Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Apr. 02, 2011
Segment Reporting Information [Line Items]
Product Sales	$ 536,627	$ 693,795
Royalty Revenues	1,920	1,356
Total Revenue	538,547	695,151
Gross Margin	136,709	214,663
Operating Income (Loss)	50,345	122,198
MOSFETS Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	94,701	142,901
Royalty Revenues	137	97
Total Revenue	94,838	142,998
Gross Margin	10,617	39,439
Operating Income	1,323	29,410
Diodes Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	120,134	159,417
Royalty Revenues	0	0
Total Revenue	120,134	159,417
Gross Margin	25,054	39,140
Operating Income	19,359	32,800
Optoelectronic Components Segments [Member]
Segment Reporting Information [Line Items]
Product Sales	50,612	57,706
Royalty Revenues	27	42
Total Revenue	50,639	57,748
Gross Margin	17,294	19,948
Operating Income	14,045	16,357
Resistors And Inductors Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	157,254	171,919
Royalty Revenues	1,756	1,217
Total Revenue	159,010	173,136
Gross Margin	54,259	61,158
Operating Income	46,512	54,104
Capacitors Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	113,926	161,852
Royalty Revenues	0	0
Total Revenue	113,926	161,852
Gross Margin	29,485	54,978
Operating Income	23,917	48,333
Unallocated Amount to Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	0	0
Royalty Revenues	0	0
Total Revenue	0	0
Gross Margin	0	0
Operating Income	$ (54,811)	$ (58,806)