Commitments and Contingencies (Schedule of Financing Guarantees Outstanding) (Details) - USD ($) $ in Millions	Jan. 23, 2016	Jul. 25, 2015
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	$ 357	$ 417
Deferred revenue associated with financing guarantees:	(190)	(234)
Maximum potential future payments relating to financing guarantees, net of associated deferred revenue	167	183
Channel partner
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	244	288
Deferred revenue associated with financing guarantees:	(100)	(127)
End user
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	113	129
Deferred revenue associated with financing guarantees:	$ (90)	$ (107)