Segment Information and Major Customers (Summary of Reportable Segments) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 26, 2019	Jan. 27, 2018	Jan. 26, 2019	Jan. 27, 2018
Segment Reporting Information [Line Items]
Revenue, total	$ 12,446	$ 11,887	$ 25,518	$ 24,023
Gross margin	7,773	7,498	15,919	14,925
Operating Segments | Americas
Segment Reporting Information [Line Items]
Revenue, total	7,352	7,004	15,103	14,354
Gross margin	4,796	4,614	9,866	9,336
Operating Segments | EMEA
Segment Reporting Information [Line Items]
Revenue, total	3,223	3,062	6,447	5,971
Gross margin	2,070	1,977	4,141	3,816
Operating Segments | APJC
Segment Reporting Information [Line Items]
Revenue, total	1,872	1,820	3,968	3,698
Gross margin	1,109	1,094	2,309	2,259
Segment Reconciling Items
Segment Reporting Information [Line Items]
Gross margin	7,975	7,685	16,316	15,411
Intersegment Eliminations
Segment Reporting Information [Line Items]
Gross margin	$ (202)	$ (187)	$ (397)	$ (486)