Pension And Postretirement Benefits (Schedule of Pension Plan Weighted-Average Asset Allocation By Cateogry) (Details) - Pension Plan, Defined Benefit [Member]	12 Months Ended
	Jul. 30, 2017	Jul. 31, 2016
Defined Benefit Plan, Information about Plan Assets [Abstract]
Defined Benefit Plan, Target Plan Asset Allocations	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, Target Plan Asset Allocations	47.00%
Defined Benefit Plan, Actual Plan Asset Allocations	48.00%	51.00%
Debt Securities [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Defined Benefit Plan, Target Plan Asset Allocations	40.00%
Defined Benefit Plan, Actual Plan Asset Allocations	40.00%	35.00%
Real Estate [Member]
Defined Benefit Plan, Information about Plan Assets [Abstract]
Defined Benefit Plan, Target Plan Asset Allocations	13.00%
Defined Benefit Plan, Actual Plan Asset Allocations	12.00%	14.00%