Goodwill and Purchased Intangible Assets (Schedule Of Amortization Of Purchased Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 29, 2017	Apr. 30, 2016	Apr. 29, 2017	Apr. 30, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	$ 59	$ 81	$ 201	$ 221
Cost of sales
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	141	134	394	419
Amortization of purchased intangible assets
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	59	81	201	221
Restructuring and other charges
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	0	0	38	0
Total
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of purchased intangible assets	$ 200	$ 215	$ 633	$ 640