Segment Information and Major Customers (Summary of Reportable Segments) (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 27, 2018	Oct. 28, 2017
Segment Reporting Information [Line Items]
Revenue, total	$ 13,072	$ 12,136
Gross margin	8,146	7,427
Operating Segments | Americas
Segment Reporting Information [Line Items]
Revenue, total	7,751	7,350
Gross margin	5,070	4,722
Operating Segments | EMEA
Segment Reporting Information [Line Items]
Revenue, total	3,224	2,909
Gross margin	2,070	1,839
Operating Segments | APJC
Segment Reporting Information [Line Items]
Revenue, total	2,096	1,877
Gross margin	1,200	1,165
Segment Reconciling Items
Segment Reporting Information [Line Items]
Gross margin	8,341	7,726
Intersegment Eliminations
Segment Reporting Information [Line Items]
Gross margin	$ (195)	$ (299)