Goodwill and Purchased Intangible Assets - Schedule of Amortization of Purchased Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 26, 2019	Oct. 27, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	$ 36	$ 34
Total
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	202	185
Cost of sales
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	166	151
Operating expenses
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	$ 36	$ 34