Income Taxes - Breakdown Between Current and Noncurrent Net Deferred Tax Assets (Details) - USD ($) $ in Millions	Jul. 25, 2020	Jul. 27, 2019
Income Tax Disclosure [Abstract]
Deferred tax assets	$ 3,990	$ 4,065
Deferred tax liabilities	(81)	(95)
Total net deferred tax assets	$ 3,909	$ 3,970