Employee Benefit Plans - Employee Stock Purchase Plan (Details) - Employee stock purchase plan	12 Months Ended
	Jul. 25, 2020 period shares	Jul. 27, 2019 shares	Jul. 28, 2018 shares
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Shares reserved for issuance (in shares)	721,400,000
Expiration period for stock options and stock appreciation rights	24 months
Number of purchase periods | period	4
Purchase period	6 months
Shares eligible for employees purchase, percentage of discount	15.00%
Shares issued under employee purchase plan, shares (in shares)	18,000,000	19,000,000	22,000,000
ESPP- shares available for issuance (in shares)	141,000,000