Segment Information and Major Customers - Summary of Net Revenue for Groups of Similar Products and Services (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 26, 2025	Apr. 27, 2024	Apr. 26, 2025	Apr. 27, 2024
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 14,149	$ 12,702	$ 41,981	$ 40,161
Total Product
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	10,374	9,024	30,722	29,395
Networking
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	7,068	6,522	20,671	22,425
Security
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	2,013	1,304	6,142	3,288
Collaboration
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	1,031	987	3,112	3,093
Observability
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	261	211	796	589
Services
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 3,775	$ 3,678	$ 11,259	$ 10,766