Pension And Postretirement Benefits (Schedule of Change In Fair Value Of Pension Assets) (Details) - Pension Plan, Defined Benefit [Member] - USD ($) $ in Millions	12 Months Ended
	Jul. 30, 2017	Jul. 31, 2016
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Fair Value of Plan Assets	$ 2,111	$ 2,316
Defined Benefit Plan, Actual Return on Plan Assets	208	54
Defined Benefit Plan, Contributions by Employer	5	2
Defined Benefit Plan, Benefits Paid, from Plan Assets	(154)	(106)
Defined Benefit Plan, Settlements, Plan Assets	0	(160)
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets	13	5
Defined Benefit Plan, Fair Value of Plan Assets	$ 2,183	$ 2,111