Financing Receivables and Guarantees (Schedule Of Financing Guarantees Outstanding) (Detail) (USD $) In Millions, unless otherwise specified	Jul. 28, 2012	Jul. 30, 2011
Guarantor Obligations [Line Items]
Maximum potential future payments relating to financing guarantees	$ 509	$ 613
Deferred revenue associated with financing guarantees	(393)	(496)
Maximum potential future payments relating to financing guarantees, net of associated deferred revenue	116	117
Channel Partner
Guarantor Obligations [Line Items]
Maximum potential future payments relating to financing guarantees	277	336
Deferred revenue associated with financing guarantees	(193)	(248)
End User
Guarantor Obligations [Line Items]
Maximum potential future payments relating to financing guarantees	232	277
Deferred revenue associated with financing guarantees	$ (200)	$ (248)