Current And Long-Term Debt (Narrative) (Details) (USD $)	0 Months Ended		3 Months Ended					0 Months Ended
	Nov. 13, 2018	Nov. 13, 2013	Nov. 30, 2013	Nov. 24, 2012	Nov. 30, 2013 Line Of Credit [Member]	Nov. 30, 2013 Standby Letters Of Credit [Member]	Nov. 30, 2013 Four Year Unsecured Revolving Credit Facility [Member] Amended [Member]	Nov. 13, 2017 ThreeHundredMillionFacility [Domain] [Domain]	Nov. 13, 2013 ThreeHundredMillionFacility [Domain] [Domain]	Nov. 30, 2013 ThreeHundredMillionFacility [Domain] [Domain]	Nov. 30, 2013 Five Year Unsecured Revolving Credit Facility [Member] Amended [Member]
Repayment of long-term debt			$ 16,200,000	$ 16,200,000
Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year			16,200,000
Line of Credit Facility, Initiation Date		Nov. 13, 2013							Nov. 13, 2013
Line of Credit Facility, Maximum Borrowing Capacity			600,000,000				400,000,000			300,000,000	300,000,000
Line of Credit Facility, Expiration Date	Nov. 13, 2018							Nov. 13, 2017
Current borrowing capacity			900,000,000
Amount outstanding					242,000,000
Line of Credit Facility, Increase (Decrease) for Period, Net			242,000,000
Line of Credit Facility, Average Daily Balance Outstanding					149,000,000
Weighted-average interest rate					1.50%
Other commercial commitments						$ 18,700,000