Pension And Postretirement Benefits (Schedule Of Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets) (Details) - Pension Plan, Defined Benefit [Member] - USD ($) $ in Millions	Jul. 30, 2017	Jul. 31, 2016
Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets [Abstract]
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Projected Benefit Obligation	$ 2,270	$ 2,434
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Accumulated Benefit Obligation	2,232	2,385
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets	$ 1,995	$ 1,933