Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Nov. 30, 2012 segment	Nov. 30, 2011
Segment Information [Abstract]
Reportable business segments	2
Company Drive-Ins	$ 93,456	$ 96,782
Franchise Operations	31,406	30,364
Unallocated revenues	1,146	1,133
Total revenues	126,008	128,279
Company Drive-Ins	11,383	11,062
Franchise Operations	31,406	30,364
Unallocated income	1,139	1,211
Selling, general and administrative	(16,130)	(15,417)
Depreciation and amortization	(10,595)	(10,466)
Income from operations	17,203	16,754
Net interest expense	7,534	7,877
Income before income taxes	$ 9,669	$ 8,877