Goodwill and Purchased Intangible Assets - Schedule of Amortization of Purchased Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 23, 2021	Jan. 25, 2020	Jan. 23, 2021	Jan. 25, 2020
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	$ 39	$ 38	$ 75	$ 74
Total
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	195	203	401	405
Cost of sales
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	156	165	326	331
Operating expenses
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	$ 39	$ 38	$ 75	$ 74