Employee Benefit Plans (Summary Of Share-Based Compensation Expense) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 28, 2012	Jul. 30, 2011	Jul. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 1,401	$ 1,620	$ 1,517
Cost Of Sales-Product
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	53	61	57
Cost Of Sales-Service
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	156	177	164
Share-Based Compensation Expense In Cost Of Sales
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	209	238	221
Research And Development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	401	481	450
Sales And Marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	588	651	602
General And Administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	203	250	244
Share-Based Compensation Expense In Operating Expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 1,192	$ 1,382	$ 1,296