Summary Of Significant Accounting Policies (Narrative) (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended		12 Months Ended
	Mar. 17, 2011	Mar. 17, 2011	Jul. 30, 2011	Jul. 31, 2010	Jul. 25, 2009
Cumulative effect of adopting revised accounting guidance related to other than temporary impairments			$ 49
Leases and loans average term, years			4
Maximum period for recognition of net asset acquired in business combinations, months			12
Purchased intangible assets, estimated useful lives, years, minimum			2
Purchased intangible assets, estimated useful lives, years, maximum			7
Percent of historical standalone transactions for determining VSOE			80.00%
Advertising costs			$ 325	$ 290	$ 165
Expected dividend yield	0.00%	0.00%	0.00%
Risk Level, High [Member]
Internal credit risk rating			10
Risk Level, Low [Member]
Internal credit risk rating			1
Minimum [Member]
Revolving short-term financing, payment terms range (in days)			60
Maximum [Member]
Revolving short-term financing, payment terms range (in days)			90
Period for recognition of technical support services revenue, in years			3