Employee Benefit Plans (Employee Stock Purchase Plan) (Details) - Employee Stock Purchase Plan - shares	12 Months Ended
	Jul. 28, 2018	Jul. 29, 2017	Jul. 30, 2016
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Shares reserved for issuance (in shares)	621,000,000
Expiration period for stock options and stock appreciation rights	24 months
Shares eligible for employees purchase, percentage of discount	15.00%
Shares issued under employee purchase plan, shares (in shares)	22,000,000	23,000,000	25,000,000
ESPP- shares available for issuance (in shares)	78,000,000