Employee Benefit Plans (Summary of Share-Based Awards Available for Grant) (Details) - shares shares in Millions	12 Months Ended
	Jul. 29, 2017	Jul. 30, 2016	Jul. 25, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Balance at beginning of fiscal year (in shares)	242	276	310
Restricted stock, stock units, and other share-based awards granted (in shares)	(76)	(96)	(101)
Share-based awards canceled/forfeited/expired (in shares)	78	30	40
Shares withheld for taxes and not issued (in shares)	28	30	27
Other (in shares)	0	2	0
Balance at end of fiscal year (in shares)	272	242	276