Employee Benefit Plans (Summary Of Stock Option Activity) (Details) - $ / shares	3 Months Ended	12 Months Ended
	Oct. 28, 2017	Jul. 29, 2017
Number Outstanding
Beginning balance (in shares)	12,000,000	73,000,000
Assumed from acquisitions (in shares)	3,000,000	8,000,000
Exercised (in shares)	(2,000,000)	(14,000,000)
Canceled/forfeited/expired (in shares)		(55,000,000)
Ending balance (in shares)	13,000,000	12,000,000
Weighted-Average Exercise Price per Share
Beginning balance (in dollars per share)	$ 6.15	$ 26.78
Assumed from acquisitions (in dollars per share)	8.07	4.47
Exercised (in dollars per share)	5.19	12.11
Canceled/forfeited/expired (in dollars per share)		31.83
Ending Balance (in dollars per share)	$ 6.68	$ 6.15