Business Combinations (Details) (USD $)	9 Months Ended
	Apr. 28, 2012	Apr. 30, 2011
Business Acquisition [Line Items]
Number of business combinations	5
Purchase Consideration	$ 361,000,000
Net Tangible Assets Acquired (Liabilities Assumed)	(36,000,000)
Purchased Intangible Assets	181,000,000
Goodwill	216,000,000
Total transaction costs related to business combination activities	9,000,000	10,000,000
Cash payment includes assumption of debt and retention-based incentives	5,000,000,000
Lightwire, Inc. [Member]
Business Acquisition [Line Items]
Purchase Consideration	239,000,000
Net Tangible Assets Acquired (Liabilities Assumed)	(15,000,000)
Purchased Intangible Assets	97,000,000
Goodwill	157,000,000
All Others [Member]
Business Acquisition [Line Items]
Purchase Consideration	122,000,000
Net Tangible Assets Acquired (Liabilities Assumed)	(21,000,000)
Purchased Intangible Assets	84,000,000
Goodwill	$ 59,000,000