Acquisitions - Net revenues and corresponding net income (loss attributable) to acquired entities (Details) (Gennum [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jul. 28, 2013	Jul. 29, 2012	Jul. 28, 2013	Jul. 29, 2012
Gennum [Member]
Net revenues and corresponding net loss attributable to acquired entities [Line Items]
Net revenue - Gennum	$ 47,376	$ 35,346	$ 87,657	$ 47,340
Net income (loss) - Gennum	$ 5,130	$ (22,741)	$ 4,320	$ (51,274)

This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)

-URI http://asc.fasb.org/extlink&oid=7659399&loc=d3e1392-128463

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph r(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration