Commitments and Contingencies (Schedule of Financing Guarantees Outstanding) (Details) (USD $) In Millions, unless otherwise specified	Oct. 25, 2014	Jul. 26, 2014
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	$ 446	$ 465
Deferred revenue associated with financing guarantees:	(256)	(293)
Maximum potential future payments relating to financing guarantees, net of associated deferred revenue	190	172
Channel partner
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	285	263
Deferred revenue associated with financing guarantees:	(126)	(127)
End user
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	161	202
Deferred revenue associated with financing guarantees:	$ (130)	$ (166)