Acquisitions and Divestitures (Additional Information) (Details) $ / shares in Units, $ in Millions		3 Months Ended
	Oct. 23, 2017 USD ($) $ / shares	Oct. 28, 2017 USD ($) acquisition	Oct. 29, 2016 USD ($)
Supplementary Information [Line Items]
Number of business combinations (acquisition) | acquisition		3
Acquired cash and cash equivalents		$ 11
Gains recognized from acquisitions		46
Purchase Consideration		761
BroadSoft, Inc
Supplementary Information [Line Items]
Share price for each share acquired (in dollars per share) | $ / shares	$ 55
Purchase Consideration	$ 1,900
General and administrative
Supplementary Information [Line Items]
Acquisition related costs		$ 9	$ 1