Consolidated Statements Of Income - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016
Revenues:
Company Drive-In sales	$ 240,722	$ 296,101	$ 425,795
Franchise Drive-Ins:
Franchise royalties and fees	172,443	170,527	170,319
Lease revenue	7,804	7,436	7,459
Other	2,621	3,203	2,747
Total revenues	423,590	477,267	606,320
Company Drive-Ins:
Food and packaging	66,583	80,971	118,136
Payroll and other employee benefits	88,008	107,477	150,260
Other operating expenses, exclusive of depreciation and amortization included below	48,586	61,463	88,424
Total cost of Company Drive-In sales	203,177	249,911	356,820
Selling, general and administrative	80,077	78,687	82,089
Depreciation and amortization	38,355	39,248	44,418
Provision for impairment of long-lived assets	664	1,140	232
Other operating income, net	(5,086)	(14,994)	(4,691)
Total costs and expenses	317,187	353,992	478,868
Income from operations	106,403	123,275	127,452
Interest expense	33,058	29,206	26,714
Interest income	(1,904)	(1,398)	(516)
Loss from debt transactions	1,310	0	8,750
Net interest expense	32,464	27,808	34,948
Income before income taxes	73,939	95,467	92,504
Provision for income taxes	2,734	31,804	28,437
Net income	$ 71,205	$ 63,663	$ 64,067
Basic income per share (usd per share)	$ 1.89	$ 1.47	$ 1.32
Diluted income per share (usd per share)	1.87	1.45	1.29
Cash dividends declared per common share (usd per share)	$ 0.64	$ 0.56	$ 0.44