Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 24, 2020	Oct. 26, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 11,929	$ 13,159
Product
Disaggregation of Revenue [Line Items]
Revenue	8,587	9,878
Infrastructure Platforms
Disaggregation of Revenue [Line Items]
Revenue	6,341	7,553
Applications
Disaggregation of Revenue [Line Items]
Revenue	1,380	1,499
Security
Disaggregation of Revenue [Line Items]
Revenue	861	816
Other Products
Disaggregation of Revenue [Line Items]
Revenue	5	11
Services
Disaggregation of Revenue [Line Items]
Revenue	$ 3,342	$ 3,281