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. 29, 2017	Apr. 30, 2016	Apr. 29, 2017	Apr. 30, 2016
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, Net	$ 11,940	$ 12,000	$ 35,872	$ 36,609
Switching
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, Net	3,489	3,435	10,510	10,919
NGN Routing
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, Net	2,032	2,074	5,938	6,057
Collaboration
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, Net	1,022	1,069	3,165	3,203
Data Center
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, Net	767	811	2,391	2,492
Wireless
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, Net	703	620	1,967	1,882
Security
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, Net	527	482	1,595	1,429
Service Provider Video
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, Net	207	296	719	1,482
Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, Net	138	88	393	238
Product
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, Net	8,885	8,875	26,678	27,702
Service
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, Net	$ 3,055	$ 3,125	$ 9,194	8,907
SP Video CPE Business
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue, Net				$ 504