Commitments and Contingencies (Schedule of Financing Guarantees Outstanding) (Details) - USD ($) $ in Millions	Oct. 28, 2017	Jul. 29, 2017
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	$ 331	$ 314
Deferred revenue associated with financing guarantees:	(125)	(134)
Maximum potential future payments relating to financing guarantees, net of associated deferred revenue	206	180
Channel partner
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	266	240
Deferred revenue associated with financing guarantees:	(79)	(82)
End user
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	65	74
Deferred revenue associated with financing guarantees:	$ (46)	$ (52)