Goodwill and Other Intangible Assets, net Intangible Assets (Details) (USD $)	12 Months Ended
	Aug. 31, 2012		Aug. 31, 2011		Aug. 31, 2010
Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,255,000	[1]	$ 1,255,000	[1]
Total Gross Carrying Amount	34,801,000		41,752,000
Accumulated Amortization	(19,023,000)		(20,846,000)
Amortization of intangible assets	5,000,000		7,000,000		6,000,000
Estimated amortization expense:
2013	4,326,000
2014	3,441,000
2015	1,950,000
2016	944,000
2017	444,000
Thereafter	3,418,000
Total	14,523,000
Covenants not to compete [Member]
Intangible Assets [Line Items]
Gross Carrying Amount	25,041,000		30,831,000
Accumulated Amortization	(13,231,000)		(15,254,000)
Supply contracts [Member]
Intangible Assets [Line Items]
Gross Carrying Amount	5,274,000		5,274,000
Accumulated Amortization	(4,274,000)		(3,376,000)
Other intangible assets subject to amortization [Member]
Intangible Assets [Line Items]
Gross Carrying Amount	3,231,000	[2]	4,392,000	[2]
Accumulated Amortization	$ (1,518,000)	[2]	$ (2,216,000)	[2]

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

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