Segment Information and Major Customers (Summary of Net Revenue for Groups of Similar Products and Services) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 27, 2018	Jan. 28, 2017	Jan. 27, 2018	Jan. 28, 2017
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, total	$ 11,887	$ 11,580	$ 24,023	$ 23,932
Infrastructure Platforms
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, total	6,694	6,545	13,664	13,818
Applications
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, total	1,184	1,116	2,387	2,252
Security
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, total	558	528	1,143	1,068
Other Products
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, total	273	302	569	655
Total Product
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, total	8,709	8,491	17,763	17,793
Service
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, total	$ 3,178	$ 3,089	$ 6,260	$ 6,139