Acquisitions and Divestitures (Additional Information) (Details) $ in Millions	3 Months Ended	9 Months Ended
	Apr. 28, 2018 USD ($) divestiture	Apr. 28, 2018 USD ($) acquisition	Apr. 29, 2017 USD ($)
Supplementary Information [Line Items]
Number of business combinations (acquisition) | acquisition		7
Acquired cash and cash equivalents		$ 174
Gains recognized from acquisitions		46
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Supplementary Information [Line Items]
Number of divestitures (divestiture) | divestiture	2
Discontinued Operations, Held-for-sale | Service Provider Video
Supplementary Information [Line Items]
Disposal group, tangible assets	$ 200	200
Disposal group, goodwill and intangible assets	300	300
Disposal group, liabilities	$ 370	370
General and administrative
Supplementary Information [Line Items]
Acquisition related costs		$ 25	$ 7