Accounts And Notes Receivable (Schedule Of Accounts And Notes Receivable) (Details) - USD ($) $ in Thousands	Aug. 31, 2018	Aug. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Royalties and other trade receivables	$ 20,177	$ 19,571
Current accounts and notes receivable, gross	35,743	34,847
Allowance for doubtful accounts and notes receivable	(776)	(1,089)
Current accounts and notes receivable, net	34,967	33,758
Allowance for doubtful notes receivable	(1,808)	(42)
Noncurrent notes receivable, net	10,932	9,801
Notes Receivable From Franchisees [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current accounts and notes receivable, gross	2,006	1,441
Noncurrent notes receivable, gross	7,597	6,810
Receivables From System Funds [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current accounts and notes receivable, gross	2,480	6,360
Noncurrent notes receivable, gross	5,143	3,033
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current accounts and notes receivable, gross	$ 11,080	$ 7,475