Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 26, 2019	Oct. 27, 2018
Income Tax Contingency [Line Items]
Benefit for provision for income taxes	$ (760)	$ (360)
Unrecognized tax benefits	2,000
Unrecognized tax benefits that would impact effective tax rate	1,700
Unrecognized tax benefits approximately reduced in next 12 months	50
Internal Revenue Service (IRS)
Income Tax Contingency [Line Items]
Income tax examination, benefit to income taxes from settlement with taxing authority	102
Internal Revenue Service (IRS) | Interest expense
Income Tax Contingency [Line Items]
Income tax examination, benefit to income taxes from settlement with taxing authority	4
Accounting Standards Update 2014-09
Income Tax Contingency [Line Items]
Benefit for provision for income taxes	$ 152