Goodwill and Purchased Intangible Assets - Schedule of Purchased Intangible Assets with Finite and Indefinite Lives (Details) - USD ($) $ in Millions	Jul. 25, 2020	Jul. 27, 2019
Finite-Lived Intangible Assets, Net [Abstract]
Gross	$ 4,084	$ 4,151
Accumulated Amortization	(2,721)	(2,286)
Total purchased intangible assets with finite lives, net	1,363	1,865
In-process research and development, with indefinite lives	213	336
Total finite and indefinite lives intangible assets, gross	4,297	4,487
Total finite and indefinite lives intangible assets, net	1,576	2,201
Technology
Finite-Lived Intangible Assets, Net [Abstract]
Gross	3,298	3,270
Accumulated Amortization	(2,336)	(1,933)
Total purchased intangible assets with finite lives, net	962	1,337
Customer relationships
Finite-Lived Intangible Assets, Net [Abstract]
Gross	760	840
Accumulated Amortization	(365)	(331)
Total purchased intangible assets with finite lives, net	395	509
Other
Finite-Lived Intangible Assets, Net [Abstract]
Gross	26	41
Accumulated Amortization	(20)	(22)
Total purchased intangible assets with finite lives, net	$ 6	$ 19