Commitments and Contingencies (Schedule of Financing Guarantees Outstanding) (Details) - USD ($) $ in Millions	Apr. 27, 2019	Jul. 28, 2018
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	$ 240	$ 308
Deferred revenue associated with financing guarantees:	(81)	(122)
Maximum potential future payments relating to financing guarantees, net of associated deferred revenue	159	186
Channel partner
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	221	277
Deferred revenue associated with financing guarantees:	(63)	(94)
End user
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	19	31
Deferred revenue associated with financing guarantees:	$ (18)	$ (28)