Property, Equipment And Capital Leases (Schedule Of Property, Equipment And Capital Leases) (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2016	Aug. 31, 2015
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 739,418	$ 733,778
Accumulated depreciation	(352,390)	(330,219)
Property and equipment, net	387,028	403,559
Capital leases	43,991	48,079
Accumulated amortization	(28,857)	(30,232)
Capital leases, net	15,134	17,847
Property, equipment and capital leases, net	402,162	421,406
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	154,420	157,861
Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	341,956	343,598
Drive-In Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	132,678	139,494
Brand Technology Development And Other Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 110,364	$ 92,825
Minimum [Member] | Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	8 years
Minimum [Member] | Drive-In Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Minimum [Member] | Brand Technology Development And Other Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	2 years
Maximum [Member] | Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	25 years
Maximum [Member] | Drive-In Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Maximum [Member] | Brand Technology Development And Other Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years