Segment Information and Major Customers - Summary of Net Revenue for Groups of Similar Products and Services (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 27, 2024	Jul. 29, 2023	Jul. 30, 2022
Segment Reporting, Revenue Reconciling Item [Line Items]
Total revenue	$ 53,803	$ 56,998	$ 51,557
Product
Segment Reporting, Revenue Reconciling Item [Line Items]
Total revenue	39,253	43,142	38,018
Networking
Segment Reporting, Revenue Reconciling Item [Line Items]
Total revenue	29,229	34,570	29,265
Security
Segment Reporting, Revenue Reconciling Item [Line Items]
Total revenue	5,075	3,859	3,699
Collaboration
Segment Reporting, Revenue Reconciling Item [Line Items]
Total revenue	4,113	4,052	4,472
Observability
Segment Reporting, Revenue Reconciling Item [Line Items]
Total revenue	837	661	581
Services
Segment Reporting, Revenue Reconciling Item [Line Items]
Total revenue	$ 14,550	$ 13,856	$ 13,539