Commitments and Contingencies (Schedule of Other Commitments) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 29, 2017	Apr. 30, 2016	Apr. 29, 2017	Apr. 30, 2016
Acquisition
Contingency [Line Items]
Compensation expense related to acquisitions	$ 36	$ 68	$ 173	$ 212