Pension And Postretirement Benefits (Schedule of Pension Plan Weighted-Average Asset Allocation By Cateogry) (Details) - Pension Plan, Defined Benefit [Member]	Jul. 29, 2018	Jul. 30, 2017
Defined Benefit Plan, Information about Plan Assets [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	100.00%
Defined Benefit Plan, Actual Plan Asset Allocations	100.00%	100.00%
Equity Securities [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	42.00%
Defined Benefit Plan, Actual Plan Asset Allocations	42.00%	48.00%
Debt Securities [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	46.00%
Defined Benefit Plan, Actual Plan Asset Allocations	46.00%	40.00%
Real Estate [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	12.00%
Defined Benefit Plan, Actual Plan Asset Allocations	12.00%	12.00%