Segment Information and Major Customers (Summary of Reportable Segments) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jul. 28, 2018	Apr. 28, 2018	Jan. 27, 2018	Oct. 28, 2017	Jul. 29, 2017	Apr. 29, 2017	Jan. 28, 2017	Oct. 29, 2016	Jul. 28, 2018	Jul. 29, 2017	Jul. 30, 2016
Segment Reporting Information [Line Items]
Revenue:	$ 12,844	$ 12,463	$ 11,887	$ 12,136	$ 12,133	$ 11,940	$ 11,580	$ 12,352	$ 49,330	$ 48,005	$ 49,247
Gross margin:	$ 7,922	$ 7,759	$ 7,498	$ 7,427	$ 7,546	$ 7,518	$ 7,276	$ 7,884	30,606	30,224	30,960
Operating Segments | Americas
Segment Reporting Information [Line Items]
Revenue:									29,070	28,351	29,392
Gross margin:									18,792	18,284	18,986
Operating Segments | EMEA
Segment Reporting Information [Line Items]
Revenue:									12,425	12,004	12,302
Gross margin:									7,945	7,855	7,998
Operating Segments | APJC
Segment Reporting Information [Line Items]
Revenue:									7,834	7,650	7,553
Gross margin:									4,726	4,741	4,620
Segment Reconciling Items
Segment Reporting Information [Line Items]
Gross margin:									31,463	30,880	31,604
Unallocated corporate items
Segment Reporting Information [Line Items]
Gross margin:									$ (857)	$ (656)	$ (644)