Commitments and Contingencies - Schedule of Financing Guarantees Outstanding (Details) - USD ($) $ in Millions	Jan. 25, 2020	Jul. 27, 2019
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	$ 271	$ 218
Deferred revenue associated with financing guarantees:	(82)	(77)
Maximum potential future payments relating to financing guarantees, net of associated deferred revenue	189	141
Channel partner
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	258	197
Deferred revenue associated with financing guarantees:	(69)	(62)
End user
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	13	21
Deferred revenue associated with financing guarantees:	$ (13)	$ (15)