Goodwill and Other Intangible Assets, net Intangible Assets (Details) (USD $)	12 Months Ended
	Aug. 31, 2011		Aug. 31, 2010		Aug. 31, 2009
Intangible Assets [Line Items]
Accumulated Amortization	$ (20,846,000)		$ (17,150,000)
Gross Carrying Amount	1,255,000	[1]	1,321,000	[1]
Gross Carrying Amount	41,752,000		37,594,000
Amortization of intangible assets	7,000,000		6,000,000		5,000,000
2012	5,430,000
2013	4,277,000
2014	3,370,000
2015	1,880,000
2016	865,000
Thereafter	3,829,000
Estimated Amortization Expense	19,651,000
Covenants not to compete [Member]
Intangible Assets [Line Items]
Gross Carrying Amount	30,831,000		27,797,000
Accumulated Amortization	(15,254,000)		(13,329,000)
Contractual Rights [Member]
Intangible Assets [Line Items]
Gross Carrying Amount	5,274,000		4,571,000
Accumulated Amortization	(3,376,000)		(2,035,000)
Other [Member]
Intangible Assets [Line Items]
Gross Carrying Amount	4,392,000	[2]	3,905,000	[2]
Accumulated Amortization	$ (2,216,000)	[2]	$ (1,786,000)	[2]

[1] Indefinite-lived intangibles include tradenames, permits and licenses and real property options.

[2] Other intangibles assets subject to amortization include tradenames, marketing agreements, employment agreements, leasehold interests, permits and licenses and real property options.