Commitments and Contingencies (Schedule of Financing Guarantees Outstanding) (Details) (USD $) In Millions, unless otherwise specified	Jul. 26, 2014	Jul. 27, 2013
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	$ 465	$ 675
Deferred revenue associated with financing guarantees:	(293)	(416)
Maximum potential future payments relating to financing guarantees, net of associated deferred revenue	172	259
Channel partner
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	263	438
Deferred revenue associated with financing guarantees:	(127)	(225)
End user
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	202	237
Deferred revenue associated with financing guarantees:	$ (166)	$ (191)