Employee Benefit Plans (Summary Of Share-Based Compensation Expense) (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 24, 2015	Oct. 25, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 376	$ 369
Income tax benefit for share-based compensation	95	94
Cost of sales—product
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	13	11
Cost of sales—service
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	38	37
Cost of sales
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	51	48
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	114	119
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	139	147
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	57	59
Restructuring and other charges
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	15	(4)
Operating expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 325	$ 321