Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Number of reportable segments	5	5
Product Sales	$ 552,274	$ 536,627
Royalty Revenues	1,980	1,920
Total Revenue	554,254	538,547
Gross Margin	136,734	136,709
Operating Income	45,605	50,345
Operating Income (Loss)	45,605	50,345
MOSFETS Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	100,846	94,701
Royalty Revenues	42	137
Total Revenue	100,888	94,838
Gross Margin	12,900	10,617
Operating Income	2,833	1,323
Diodes Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	125,112	120,134
Royalty Revenues	0	0
Total Revenue	125,112	120,134
Gross Margin	27,261	25,054
Operating Income	21,389	19,359
Optoelectronic Components Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	56,226	50,612
Royalty Revenues	0	27
Total Revenue	56,226	50,639
Gross Margin	19,774	17,294
Operating Income	16,209	14,045
Resistors And Inductors Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	163,928	157,254
Royalty Revenues	1,938	1,756
Total Revenue	165,866	159,010
Gross Margin	52,601	54,259
Operating Income	44,200	46,512
Capacitors Segment [Member]
Segment Reporting Information [Line Items]
Product Sales	106,162	113,926
Royalty Revenues	0	0
Total Revenue	106,162	113,926
Gross Margin	24,198	29,485
Operating Income	18,456	23,917
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	$ (57,482)	$ (54,811)