Acquisitions and Divestitures (Additional Information) (Details) $ in Millions		3 Months Ended		6 Months Ended
	Feb. 01, 2018 USD ($)	Jan. 27, 2018 divestiture	Oct. 28, 2017 USD ($)	Jan. 27, 2018 USD ($) acquisition	Jan. 28, 2017 USD ($)
Supplementary Information [Line Items]
Number of business combinations (acquisition) | acquisition				5
Acquired cash and cash equivalents				$ 12
Gains recognized from acquisitions			$ 46
Purchase consideration				788
BroadSoft, Inc | Subsequent Event
Supplementary Information [Line Items]
Purchase consideration	$ 1,900
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Supplementary Information [Line Items]
Number of divestitures (divestiture) | divestiture		2
General and administrative
Supplementary Information [Line Items]
Acquisition related costs				$ 14	$ 3