ASSET RETIREMENT OBLIGATIONS (ARO) (Details) (USD $) In Thousands	12 Months Ended
Sep. 30, 2011	Sep. 30, 2010
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at October 1	$ 26,009	$ 25,097
Accretion	1,663	1,572
Additions	180	149
Retirements	(826)	(809)
Balance at period end	27,026	26,009
Future Accretion [Abstract]
2012	1,754
2013	1,849
2014	1,931
2015	1,991
2016	2,051
Total	$ 9,576

Future Accretion associated with an asset retirement obligation

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Future Accretion [Abstract]

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Future Accretion, Year Five

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Future Accretion, Year Four

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Future Accretion, Year One

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Future Accretion, Year Three

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Future Accretion, Year Two

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The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 143

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-Publisher FASB

-Name Accounting Standards Codification

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-Name Accounting Standards Codification

-Glossary Asset Retirement Obligation

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Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Amount of asset retirement obligations incurred during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

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Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 143

-Paragraph 22

-Subparagraph c(2)

-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.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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