Income Taxes (Additional Information) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Oct. 27, 2018	Oct. 28, 2017	Jul. 28, 2018
Income Tax Contingency [Line Items]
Benefit for provision for income taxes	$ (360)	$ (568)
Tax Cuts and Jobs Act of 2017, provisional tax expense			$ 10,400
Tax Cuts and Jobs Act of 2017, transition tax expense (benefit)	8,100		$ (863)
Tax Cuts and Jobs Act of 2017, tax expense for foreign withholding tax	1,200
Tax Cuts and Jobs Act of 2017, re-measurement of net deferred tax assets	1,100
Unrecognized tax benefits	1,900
Unrecognized tax benefits that would impact effective tax rate	1,700
Unrecognized tax benefit that could be reduced in next 12 months	200
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Income Tax Contingency [Line Items]
Benefit for provision for income taxes	$ 152