Taxes on Earnings Schedule of Activity Related to Unrecognized Tax Benefits (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Aug. 03, 2014	Jul. 28, 2013	Jul. 29, 2012
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits	$ 61	$ 48	$ 43
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	0	28	2
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions	(1)	(7)	(1)
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	11	9	9
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	0	(15)	0
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	0	(2)	(5)
Unrecognized Tax Benefits	$ 71	$ 61	$ 48