Commitments and Contingencies (Schedule of Other Commitments) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 28, 2017	Jan. 23, 2016	Jan. 28, 2017	Jan. 23, 2016
Acquisition
Contingency [Line Items]
Compensation expense related to acquisitions	$ 73	$ 71	$ 137	$ 144