Goodwill And Purchased Intangible Assets (Schedule Of Intangible Assets Acquired Through Business Combinations) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Apr. 28, 2012
Schedule Of Finite Lived And Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired indefinite and finite lives intangible assets	$ 181
Technology [Member]
Schedule Of Finite Lived And Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired finite lives	181
Lightwire, Inc. [Member]
Schedule Of Finite Lived And Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired indefinite and finite lives intangible assets	97
Lightwire, Inc. [Member] | Technology [Member]
Schedule Of Finite Lived And Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	5.0
Amount, acquired finite lives	97
All Others [Member]
Schedule Of Finite Lived And Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired indefinite and finite lives intangible assets	84
All Others [Member] | Technology [Member]
Schedule Of Finite Lived And Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	3.6
Amount, acquired finite lives	$ 84