Debt (Shelf Facility Agreements) (Narrative) (Details)	9 Months Ended
	May 30, 2020 USD ($)
Line of Credit Facility [Line Items]
Maximum consolidated leverage ratio of total indebtedness to EBITDA	3.00
Maximum consolidated leverage ratio of total indebtedness to EBITDA after material acquisition	3.50
Minimum consolidated interest coverage ratio of EBITDA to total interest expense	3.00
Met Life Note Purchase Agreement [Member]
Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity	$ 250,000,000
Remaining borrowing capacity	160,000,000
Prudential Note Purchase Agreement [Member]
Line of Credit Facility [Line Items]
Credit facility, maximum borrowing capacity	250,000,000
Remaining borrowing capacity	$ 200,000,000