Commitments and Contingencies (Schedule of Financing Guarantees Outstanding) (Details) - USD ($) $ in Millions	Jul. 28, 2018	Jul. 29, 2017
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	$ 308	$ 314
Deferred revenue associated with financing guarantees:	(122)	(134)
Maximum potential future payments relating to financing guarantees, net of associated deferred revenue	186	180
Channel partner
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	277	240
Deferred revenue associated with financing guarantees:	(94)	(82)
End user
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	31	74
Deferred revenue associated with financing guarantees:	$ (28)	$ (52)