Revenue - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	May 01, 2021	Apr. 25, 2020	May 01, 2021	Apr. 25, 2020	Jul. 25, 2020
Disaggregation of Revenue [Line Items]
Allowance for future sales returns	$ 61		$ 61		$ 79
Payment terms			30 days
Accounts receivable, net	4,425		$ 4,425		5,472
Deferred revenue	20,889		20,889		20,446
Revenue recognized	2,600		9,500
Total deferred sales commissions	893		893		732
Amortization of sales commissions, expense	134	$ 118	386	$ 356
Software and Service Agreements
Disaggregation of Revenue [Line Items]
Contract assets, net of allowances	$ 1,300		$ 1,300		$ 1,200