Employee Benefit Plans (Summary Of Share-Based Compensation Expense) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 27, 2012	Oct. 29, 2011
Option Indexed to Issuer's Equity [Line Items]
Allocated Share-based Compensation Expense	$ 306	$ 341
Cost Of Sales Product [Member]
Option Indexed to Issuer's Equity [Line Items]
Allocated Share-based Compensation Expense	10	13
Cost Of Sales-Service [Member]
Option Indexed to Issuer's Equity [Line Items]
Allocated Share-based Compensation Expense	35	37
Share-Based Compensation Expense In Cost Of Sales [Member]
Option Indexed to Issuer's Equity [Line Items]
Allocated Share-based Compensation Expense	45	50
Research And Development [Member]
Option Indexed to Issuer's Equity [Line Items]
Allocated Share-based Compensation Expense	84	101
Sales And Marketing [Member]
Option Indexed to Issuer's Equity [Line Items]
Allocated Share-based Compensation Expense	130	142
General And Administrative [Member]
Option Indexed to Issuer's Equity [Line Items]
Allocated Share-based Compensation Expense	50	48
Restructuring And Other Charges [Member]
Option Indexed to Issuer's Equity [Line Items]
Allocated Share-based Compensation Expense	(3)	0
Share-Based Compensation Expense In Operating Expenses [Member]
Option Indexed to Issuer's Equity [Line Items]
Allocated Share-based Compensation Expense	$ 261	$ 291