Employee Benefit Plans - Employee Stock Purchase Plan (Details) - Employee Stock Purchase Plan - shares	12 Months Ended
	Jul. 27, 2019	Jul. 28, 2018	Jul. 29, 2017
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Shares reserved for issuance (in shares)	721,400,000.0
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)	19,000,000	22,000,000	23,000,000
ESPP- shares available for issuance (in shares)	159,000,000