Stock-Based Compensation (Schedule Of Stock Option Activity) (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	9 Months Ended
	Apr. 29, 2012
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Beginning of year, Options	8,706
Granted, Options	0
Exercised, Options	(3,609)
Terminated, Options	(75)
End of year, Options	5,022
Exercisable at end of period, Options	5,022
Beginning of period, Weighted-Average Exercise Price	$ 26.23
Granted, Weighted-Average Exercise Price	$ 0.00
Exercised, Weighted-Average Exercise Price	$ 26.11
Terminated, Weighted-Average Exercise Price	$ 26.62
End of period, Weighted-Average Exercise Price	$ 26.32
Exercisable at end of period, Weighted-Average Exercise Price	$ 26.32
Outstanding at end of period, Weighted-Average Remaining Contractual Life (In years)	1.8
Exercisable at end of period, Weighted-Average Remaining Contractual Life (In years)	1.8
Outstanding at end of period, Aggregate Intrinsic Value	$ 38
Exercisable at end of period, Aggregate Intrinsic Value	$ 38