Condensed Consolidated Statements Of Income - USD ($) $ in Thousands	3 Months Ended
	Nov. 30, 2016	Nov. 30, 2015
Revenues [Abstract]
Company Drive-In sales	$ 87,152	$ 103,883
Franchise Drive-Ins:
Franchise royalties and fees	40,139	39,922
Lease revenue	1,381	1,592
Other	879	406
Total revenues	129,551	145,803
Costs and expenses:
Food and packaging	24,116	28,946
Payroll and other employee benefits	31,766	36,364
Other operating expenses, exclusive of depreciation and amortization included below	19,426	22,908
Total cost of Company Drive-In sales	75,308	88,218
Selling, general and administrative	19,754	20,940
Depreciation and amortization	10,277	10,999
Other operating income, net	(2,840)	(399)
Total costs and expenses	102,499	119,758
Income from operations	27,052	26,045
Interest expense	7,189	6,222
Interest income	(494)	(100)
Net interest expense	6,695	6,122
Income before income taxes	20,357	19,923
Provision for income taxes	7,239	7,465
Net income	$ 13,118	$ 12,458
Basic income per share (usd per share)	$ 0.29	$ 0.25
Diluted income per share (usd per share)	0.28	0.24
Cash dividends declared per common share (usd per share)	$ 0.14	$ 0.11