Acquisitions and Divestitures (Divestiture Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jan. 23, 2016	Jul. 29, 2017	Jul. 30, 2016	Jul. 25, 2015
Divestiture [Line Items]
Cash consideration		$ 0	$ 372	$ 0
Client premises equipment portion of SPV connected devices BU
Divestiture [Line Items]
Divestiture, consideration received	$ 542
Cash consideration	372
Equity fair value as of divestiture date	170
Divestiture gain, net of transaction costs	$ 253