Property, Equipment And Capital Leases (Schedule Of Property, Equipment And Capital Leases) (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2015	Aug. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 733,778	$ 720,776
Accumulated depreciation related to buildings and equipment	(330,219)	(298,580)
Property and equipment, net	403,559	422,196
Capital leases	48,079	50,243
Accumulated amortization	(30,232)	(30,470)
Capital leases, net	17,847	19,773
Property, equipment and capital leases, net	421,406	441,969
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	157,861	156,336
Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	343,256	345,309
Drive-In Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	139,801	136,556
Brand Technology Development And Other Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 92,860	$ 82,575
Minimum [Member] | Buildings [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 [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