Pension And Postretirement Benefits (Schedule of Assumed Health Care Cost Trend Rates) (Details) (Other Postretirement Benefit Plans, Defined Benefit [Member])	12 Months Ended
	Jul. 28, 2013	Jul. 29, 2012
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year	8.25%	8.25%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	4.50%	4.50%
Defined Benefit Plan, Year that Rate Reaches Ultimate Trend Rate	2021	2020