Income Taxes - Income Before Provision for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
Oct. 26, 2019	Oct. 27, 2018
Income Tax Disclosure [Abstract]
Income before provision for income taxes	$ 3,686	$ 3,909
Provision for income taxes	$ 760	$ 360
Effective tax rate	20.60%	9.20%

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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