Investments - Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Oct. 28, 2012	Jul. 28, 2013 Minimum [Member]	Jul. 28, 2013 Temporary Investments [Member] Minimum [Member]	Jul. 28, 2013 Temporary Investments [Member] Maximum [Member]	Jul. 28, 2013 Long-Term Investments [Member] Minimum [Member]
Investment [Line Items]
Investment maturity period		3 months	3 months	12 months	12 months
Purchase of cost method investment	$ 2.5

The cash outflow associated with other investments held by the entity for investment purposes not otherwise defined in the taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3213-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 15

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration