Pension And Postretirement Benefits (Schedule Of Assumed Health Care Cost Trend Rates) (Details) - Other Postretirement Benefit Plan, Defined Benefit [Member]	12 Months Ended
	Jul. 30, 2017	Jul. 31, 2016
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year	7.25%	7.25%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	4.50%	4.50%
Defined Benefit Plan, Year that Rate Reaches Ultimate Trend Rate	2023	2022