Number of distributor representing more than ten percent of entity's net sales during the period.

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- Definition

Percentage of net sales from external customers attributed to entity's largest distributor from which net sales is material.

+ Details

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- Definition

Percentage of net sales from external customers attributed to an individual country or group of countries from which net sales is greater than 10%.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, and production equipment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 13
-Subparagraph a
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 12
-Paragraph 5
-Subparagraph b, c

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 8
-Article 7

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Amount of profit or loss recognized by the reportable segment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 131
-Paragraph 27

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Amount of total revenue for the reportable segment, including revenue from external customers, transactions with other operating segments of the same entity, and (gross) interest revenue. All considered to be "operating revenue" for purposes of the taxonomy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 131
-Paragraph 27
-Subparagraph a, b, c

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Geographic and Segment Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2011	Mar. 31, 2010	Mar. 31, 2009
Segment reporting information [Line Items]
Net sales	$ 1,487,205
Gross profit	874,436
Schedule of identifiable long-lived assets [Abstract]
Amount of identifiable long-lived assets (consisting of property, plant and equipment)	540,513	493,039
Entity-Wide Disclosure on Geographic Areas, Revenue from External Customers Attributed to Individual Foreign Countries [Line Items]
Number of distributor with more than 10 percent of entity's net sales (in number of distributor)	1
Percentage of net sales from largest distributor (in hundredths)	10.00%	12.00%	14.00%
Semiconductor products [Member]
Segment reporting information [Line Items]
Net sales	1,415,137
Gross profit	806,398
Technology licensing [Member]
Segment reporting information [Line Items]
Net sales	72,068
Gross profit	68,038
United States [Member]
Schedule of identifiable long-lived assets [Abstract]
Amount of identifiable long-lived assets (consisting of property, plant and equipment)	330,046	332,920
Thailand [Member]
Schedule of identifiable long-lived assets [Abstract]
Amount of identifiable long-lived assets (consisting of property, plant and equipment)	193,729	147,732
Various other countries [Member]
Schedule of identifiable long-lived assets [Abstract]
Amount of identifiable long-lived assets (consisting of property, plant and equipment)	$ 16,738	$ 12,387
Located outside US, in aggregate [Member]
Entity-Wide Disclosure on Geographic Areas, Revenue from External Customers Attributed to Individual Foreign Countries [Line Items]
Percentage of net sales to unaffiliated customers in one country or geographic area. (in hundredths)	80.00%	77.00%	75.00%
Europe [Member]
Entity-Wide Disclosure on Geographic Areas, Revenue from External Customers Attributed to Individual Foreign Countries [Line Items]
Percentage of net sales to unaffiliated customers in one country or geographic area. (in hundredths)	23.00%	25.00%	29.00%
Asia [Member]
Entity-Wide Disclosure on Geographic Areas, Revenue from External Customers Attributed to Individual Foreign Countries [Line Items]
Percentage of net sales to unaffiliated customers in one country or geographic area. (in hundredths)	57.00%	51.00%	46.00%
China, including Hong-Kong [Member]
Entity-Wide Disclosure on Geographic Areas, Revenue from External Customers Attributed to Individual Foreign Countries [Line Items]
Percentage of net sales to unaffiliated customers in one country or geographic area. (in hundredths)	25.00%	25.00%	23.00%
Taiwan [Member]
Entity-Wide Disclosure on Geographic Areas, Revenue from External Customers Attributed to Individual Foreign Countries [Line Items]
Percentage of net sales to unaffiliated customers in one country or geographic area. (in hundredths)	13.00%	10.00%