Stock-based Compensation (Schedule Of Stock Option Activity) (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	6 Months Ended
	Jan. 27, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Beginning of year, Options	4,254
Granted, Options	0
Exercised, Options	(1,898)
Terminated, Options	0
End of year, Options	2,356
Exercisable at end of period, Options	2,356
Beginning of period, Weighted-Average Exercise Price	$ 26.73
Granted, Weighted-Average Exercise Price	$ 0.00
Exercised, Weighted-Average Exercise Price	$ 26.47
Terminated, Weighted-Average Exercise Price	$ 0.00
End of period, Weighted-Average Exercise Price	$ 26.94
Exercisable at end of period, Weighted-Average Exercise Price	$ 26.94
Outstanding at end of period, Weighted-Average Remaining Contractual Life (In years)	1 year 5 months
Exercisable at end of period, Weighted-Average Remaining Contractual Life (In years)	1 year 5 months
Outstanding at end of period, Aggregate Intrinsic Value	$ 23
Exercisable at end of period, Aggregate Intrinsic Value	$ 23