Goodwill and Intangible Assets (Details) (USD $) In Thousands	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Subject to amortization:
Accumulated amortization	$ (35,671)	$ (27,613)
Intangible assets, net	41,542	37,590
Not subject to amortization:
Goodwill	691,910	678,721	665,663
Customer relationships and noncompete agreements [Member]
Subject to amortization:
Customer relationships and noncompete agreements	$ 77,213	$ 65,203

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details