Revenue (Additional Information) (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 27, 2018	Jul. 29, 2018	Jul. 28, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Payment terms	30 days
Accounts receivable, net	$ 4,536	$ 5,450	$ 5,554
Total contract assets	5,500
Total deferred revenue	16,814		19,685
Revenue recognized	3,400
Remaining performance obligation	22,300
Total deferred sales commissions	673		644
Amortization of sales commissions, expense	112
Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net		(104)
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total deferred revenue	2,800	$ 2,800
Software and Service Agreements
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total contract assets	$ 447		$ 122