Goodwill And Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Millions	Jan. 29, 2017	Jul. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 296	$ 297
Finite-Lived Intangible Assets, Accumulated Amortization	(81)	(72)
Finite-Lived Intangible Assets, Net	215	225
Indefinite-Lived Intangible Assets (Excluding Goodwill)	900	927
Total net intangible assets	1,115	1,152
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	221	222
Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	40	40
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 35	$ 35