Business Combinations Intangible Assets Acquired (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 31, 2011 Y
Acquired Intangible Assets [Line Items]
Weighted Average Life In Years	4.4
Gross Carrying Amount	$ 7,182
Gross Carrying Amount	257	[1]
Covenants not to compete [Member]
Acquired Intangible Assets [Line Items]
Weighted Average Life In Years	4.8
Gross Carrying Amount	6,062
Other intangible assets subject to amortization [Member]
Acquired Intangible Assets [Line Items]
Weighted Average Life In Years	1.5	[2]
Gross Carrying Amount	$ 863	[2]

[1] Indefinite-lived intangible assets include tradenames and real property options.

[2] Other intangible assets subject to amortization include supply contracts, permits and licenses and leasehold interests.