Segment Information and Major Customers (Summary Of Net Revenue For Groups Of Similar Products And Services) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 27, 2013	Jul. 28, 2012	Jul. 30, 2011
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 48,607	$ 46,061	$ 43,218
Service
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	10,578	9,735	8,692
Sales Revenue, Product Line | Switching
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	14,741	14,589	14,177
Sales Revenue, Product Line | NGN Routing
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	8,230	8,382	8,186
Sales Revenue, Product Line | Service Provider Video
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	4,852	3,861	3,515
Sales Revenue, Product Line | Collaboration
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	3,956	4,193	4,072
Sales Revenue, Product Line | Wireless
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	2,166	1,659	1,400
Sales Revenue, Product Line | Data Center [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	2,073	1,298	696
Sales Revenue, Product Line | Security
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	1,347	1,341	1,191
Sales Revenue, Product Line | Other products
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	664	1,003	1,289
Sales Revenue, Product Line | Product
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 38,029	$ 36,326	$ 34,526