Commitments and Contingencies (Schedule of Financing Guarantees Outstanding) (Details) - USD ($) $ in Millions	Oct. 27, 2018	Jul. 28, 2018
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	$ 335	$ 308
Deferred revenue associated with financing guarantees:	(98)	(122)
Maximum potential future payments relating to financing guarantees, net of associated deferred revenue	237	186
Channel partner
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	307	277
Deferred revenue associated with financing guarantees:	(72)	(94)
End user
Loss Contingencies [Line Items]
Maximum potential future payments relating to financing guarantees:	28	31
Deferred revenue associated with financing guarantees:	$ (26)	$ (28)