Goodwill And Purchased Intangible Assets (Schedule Of Amortization Of Purchased Intangible Assets) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 26, 2013	Jan. 28, 2012	Jan. 26, 2013	Jan. 28, 2012
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of Acquired Intangible Assets	$ 263	$ 196	$ 528	$ 391
Cost of Sales [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of Acquired Intangible Assets	145	99	288	195
Operating Expenses [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of Acquired Intangible Assets	$ 118	$ 97	$ 240	$ 196