Commitments and Contingencies - Schedule of Financing Guarantees Outstanding (Details) - USD ($) $ in Millions	Apr. 25, 2020	Jul. 27, 2019
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	$ 215	$ 218
Deferred revenue associated with financing guarantees:	(70)	(77)
Maximum potential future payments relating to financing guarantees, net of associated deferred revenue	145	141
Channel partner
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	203	197
Deferred revenue associated with financing guarantees:	(59)	(62)
End user
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	12	21
Deferred revenue associated with financing guarantees:	$ (11)	$ (15)