Employee Benefit Plans (Summary Of Stock Option Activity) (Details) - $ / shares	6 Months Ended	12 Months Ended
	Jan. 28, 2017	Jul. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, Number Outstanding, options (in shares)	73,000,000	103,000,000
Assumed from acquisitions (in shares)	1,000,000	18,000,000
Exercised (in shares)	(6,000,000)	(32,000,000)
Canceled/forfeited/expired (in shares)	(55,000,000)	(16,000,000)
Ending balance, Number Outstanding, options (in shares)	13,000,000	73,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted-Average Exercise Price per Share, Beginning Balance (in dollars per share)	$ 26.78	$ 28.68
Assumed from acquisitions, Weighted-Average Exercise Price per Share (in dollars per share)	1.59	5.17
Exercised, Weighted-Average Exercise Price per Share (in dollars per share)	17.43	19.22
Canceled/forfeited/expired, Weighted-Average Exercise Price per Share (in dollars per share)	31.95	30.01
Weighted-Average Exercise Price per Share, Ending Balance (in dollars per share)	$ 8.23	$ 26.78