Pension And Postretirement Benefits (Schedule of Pension Plan Weighted-Average Asset Allocation By Cateogry) (Details) - Pension Plan, Defined Benefit [Member]	Jul. 28, 2019	Jul. 29, 2018
Defined Benefit Plan, Information about Plan Assets [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	100.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	100.00%	100.00%
Equity Securities [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	39.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	42.00%	42.00%
Debt Securities [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	50.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	46.00%	46.00%
Real Estate [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	11.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	12.00%	12.00%