Goodwill And Purchased Intangible Assets (Schedule Of Purchased Intangible Assets With Finite And Indefinite Lives) (Detail) (USD $) In Millions, unless otherwise specified	Jan. 26, 2013	Jul. 28, 2012
Business Acquisition [Line Items]
Intangible Assets Gross Excluding Goodwill	$ 6,627
Finite-Lived Intangible Assets, Accumulated Amortization	(3,085)
Intangible Assets, Net (Excluding Goodwill)	3,542	1,959
Technology [Member]
Business Acquisition [Line Items]
Intangible Assets Gross Excluding Goodwill	3,400	2,267
Finite-Lived Intangible Assets, Accumulated Amortization	(1,154)	(908)
Intangible Assets, Net (Excluding Goodwill)	2,246	1,359
Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible Assets Gross Excluding Goodwill	3,118	2,261
Finite-Lived Intangible Assets, Accumulated Amortization	(1,890)	(1,669)
Intangible Assets, Net (Excluding Goodwill)	1,228	592
Finite Lived Intangible Other [Member]
Business Acquisition [Line Items]
Intangible Assets Gross Excluding Goodwill	67	49
Finite-Lived Intangible Assets, Accumulated Amortization	(41)	(41)
Intangible Assets, Net (Excluding Goodwill)	26	8
Total Purchased Intangible Assets With Finite Lives [Member]
Business Acquisition [Line Items]
Intangible Assets Gross Excluding Goodwill	6,585	4,577
Finite-Lived Intangible Assets, Accumulated Amortization	(3,085)	(2,618)
Intangible Assets, Net (Excluding Goodwill)	3,500	1,959
In Process Research And Development With Indefinite Lives [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	0
Gross In Process Research Development With Indefinite Lives	42
Net In Process Research Development With Indefinite Lives	$ 42