Employee Benefit Plans (Summary Of Stock Option Activity) (Details) (USD $) In Millions, except Per Share data	12 Months Ended
	Jul. 30, 2011		Jul. 31, 2010		Jul. 25, 2009
Employee Benefit Plans
Number outstanding, beginning balance	732		1,004		1,199
Granted and assumed, number outstanding			15		14
Exercised, number outstanding	(80)	[1]	(158)	[1]	(33)	[1]
Canceled/forfeited/expired, number outstanding	(31)		(129)		(176)
Number outstanding, ending balance	621		732		1,004
Weighted-average exercise price per share, beginning balance	$ 21.39		$ 24.29		$ 27.83
Granted and assumed, weighted-average exercise price per share			$ 13.23		$ 19.01
Exercised, weighted-average exercise price per share	$ 16.55	[1]	$ 17.88	[1]	$ 14.67	[1]
Canceled/forfeited/expired, weighted-average exercise price per share	$ 25.91		$ 47.31		$ 49.79
Weighted-average exercise price per share, ending balance	$ 21.79		$ 21.39		$ 24.29

[1] The total pretax intrinsic value of stock options exercised during fiscal 2011, 2010, and 2009 was $312 million, $1.0 billion, and $158 million, respectively.