Commitments and Contingencies (Schedule of Financing Guarantees Outstanding) (Details) - USD ($) $ in Millions	Jul. 25, 2015	Jul. 26, 2014
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	$ 417	$ 465
Deferred revenue associated with financing guarantees:	(234)	(293)
Maximum potential future payments relating to financing guarantees, net of associated deferred revenue	183	172
Channel partner
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	288	263
Deferred revenue associated with financing guarantees:	(127)	(127)
End user
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	129	202
Deferred revenue associated with financing guarantees:	$ (107)	$ (166)