Segment Information and Major Customers - Additional Information (Details) $ in Millions	3 Months Ended								12 Months Ended
	Jul. 25, 2020 USD ($)	Apr. 25, 2020 USD ($)	Jan. 25, 2020 USD ($)	Oct. 26, 2019 USD ($)	Jul. 27, 2019 USD ($)	Apr. 27, 2019 USD ($)	Jan. 26, 2019 USD ($)	Oct. 27, 2018 USD ($)	Jul. 25, 2020 USD ($) segment	Jul. 27, 2019 USD ($)	Jul. 28, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of geographic segments | segment									3
Revenue	$ 12,154	$ 11,983	$ 12,005	$ 13,159	$ 13,428	$ 12,958	$ 12,446	$ 13,072	$ 49,301	$ 51,904	$ 49,330
United States
Segment Reporting Information [Line Items]
Revenue									$ 26,100	$ 27,400	$ 25,500