Goodwill and Purchased Intangible Assets (Schedule of Goodwill by Reportable Segments) (Details) $ in Millions	6 Months Ended
	Jan. 27, 2018 USD ($)
Goodwill [Roll Forward]
Beginning Balance	$ 29,766
Acquisitions	458
Other	167
Ending Balance	30,391
Americas
Goodwill [Roll Forward]
Beginning Balance	18,691
Acquisitions	337
Other	101
Ending Balance	19,129
EMEA
Goodwill [Roll Forward]
Beginning Balance	7,057
Acquisitions	93
Other	42
Ending Balance	7,192
APJC
Goodwill [Roll Forward]
Beginning Balance	4,018
Acquisitions	28
Other	24
Ending Balance	$ 4,070