Goodwill and Purchased Intangible Assets (Schedule of Amortization of Purchased Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 27, 2019	Apr. 28, 2018	Apr. 27, 2019	Apr. 28, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	$ 39	$ 67	$ 112	$ 188
Cost of sales
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	157	177	464	491
Share-based compensation expense in operating expenses
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	39	67	112	188
Total
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	$ 196	$ 244	$ 576	$ 679