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Concentration of Risk - Narrative (Details) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Apr. 29, 2018 | Apr. 30, 2017 | Jan. 28, 2018
Concentration Risk [Line Items] |  |  |
Description of geographic concentration risk related to distributors | For the third quarter of fiscal year 2018, our two largest distributors were based in Asia. |  |
Accounts Receivable [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Minimum concentration risk threshold | 10.00% |  | 10.00%
Net sales [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Minimum concentration risk threshold | 10.00% |  |
Concentration risk, percentage | 100.00% | 100.00% |
Net sales [Member] | Distributor concentration risk [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk, percentage | 69.00% | 64.00% |
China | Cost of Silicon Wafers [Member] | Supplier concentration risk [Member] |  |  |
Concentration Risk [Line Items] |  |  |
Concentration risk, percentage | 14.00% | 21.00% |

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- Definition Description of risks that arise due to concentrations of operating facilities, revenues, assets, customers, vendors or the like in a certain geographic area, either domestic or foreign. The description may address risks inherent in the geographic area, and, at a minimum, informs users of the general nature of the risk, but excludes "Information about Geographic Areas" that may be disclosed elsewhere (for instance, segment disclosures).. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6327-108592 + 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. + References No definition available. + Details
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- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611 + Details
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