Employee Benefit Plans (Summary Of Stock Option Activity) (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	6 Months Ended	12 Months Ended
	Jan. 25, 2014	Jul. 27, 2013
Summary of Stock Option Activity
Beginning balance, Number Outstanding (in shares)	276	520
Share Based Compensation Arrangement By Share Based Payment Award Options Assumed From Acquisitions In Period	6	10
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)	(33)	(154)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period	(11)	(100)
Ending balance, Number Outstanding (in shares)	238	276
Weighted-average exercise price per share, beginning balance	$ 24.44	$ 22.68
Share Based Compensation Arrangement By Share Based Payment Award Options Assumed From Acquisition In Period Weighted Average Exercise Price	$ 3.69	$ 0.77
Exercised, weighted-average exercise price per share	$ 17.85	$ 18.51
Canceled/forfeited/expired, weighted-average exercise price per share	$ 27.36	$ 22.18
Weighted-average exercise price per share, beginning balance	$ 24.70	$ 24.44