Revenue - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 25, 2020	Jul. 27, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Payment terms	30 days
Accounts receivable, net	$ 5,472	$ 5,491
Deferred revenue	20,446	18,467
Revenue recognized	10,600
Total deferred sales commissions	732	750
Amortization of sales commissions, expense	477	471
Software and Service Agreements
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total contract assets	$ 1,200	$ 860