Goodwill And Purchased Intangible Assets (Schedule Of Amortization Of Purchased Intangible Assets) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 27, 2012	Oct. 29, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of Acquired Intangible Assets	$ 265	$ 195
Cost of Sales [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of Acquired Intangible Assets	143	96
Operating Expenses [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of Acquired Intangible Assets	$ 122	$ 99