Goodwill And Other Intangibles (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 75,344	$ 75,756	$ 76,734
Gross carrying amount of franchise agreements, intellectual property franchise fees and other intangibles	5,900	9,300
Accumulated amortization of intangible assets	3,400	6,600
Amortization of intangible assets	$ 300	$ 1,000	$ 900
Weighted-average life of amortizable intangible assets	10 years 8 months 12 days
Estimated intangible assets amortization expense, 2019	$ 300
Estimated intangible assets amortization expense, 2020	300
Estimated intangible assets amortization expense, 2021	300
Estimated intangible assets amortization expense, 2022	300
Estimated intangible assets amortization expense, 2023	$ 200