Supplemental Financial Statement Data (Schedule of Statements of Cash Flow) (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 30, 2017	Jul. 31, 2016	Aug. 02, 2015
Statement of Financial Position [Abstract]
Employee Benefits And Deferred Compensation Payments	$ (53)	$ (55)	$ (53)
Other Operating Activities, Cash Flow Statement	0	(3)	1
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities	(53)	(58)	(52)
Interest Paid	110	113	111
Interest Received	5	4	3
Income Taxes Paid, Net	$ 320	$ 325	$ 333