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. 24, 2026	Jan. 25, 2025	Jan. 24, 2026	Jan. 25, 2025
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 15,349	$ 13,991	$ 30,232	$ 27,832
Total Product
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	11,642	10,234	22,719	20,348
Networking
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	8,294	6,850	16,061	13,603
Security
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	2,018	2,111	3,998	4,129
Collaboration
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	1,054	996	2,109	2,081
Observability
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	277	277	550	535
Services
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 3,707	$ 3,757	$ 7,513	$ 7,484