Restructuring And Other Charges (Additional Information) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 26, 2013	Oct. 27, 2012
August Fiscal 2014 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected Number of Positions Eliminated (headcounts)	4,000
Restructuring, position eliminated of total positions, percent	5.00%
Restructuring and Related Cost, Cost Incurred to Date	$ 237
Restructuring and Related Cost, Expected Cost	550
Restructuring Reserve	170
Restructuring Charges	237
Fiscal 2011 Plans
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	1,100
Restructuring Reserve	22
Restructuring Charges	$ 0	$ 59