Taxes on Earnings Schedule of Activity Related to Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 29, 2018	Jul. 30, 2017	Jul. 31, 2016
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits	$ 64	$ 63	$ 58
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	0	4	2
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions	(37)	0	0
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	2	4	3
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	(1)	(7)	0
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	4	0	0
Unrecognized Tax Benefits	$ 32	$ 64	$ 63