COMMITMENTS AND CONTINGENT LIABILITIES, LEGAL PROCEEDINGS (Details) (USD $)							12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Enviromental remediation costs expended, net of recoveries [Member]	Sep. 30, 2010 Enviromental remediation costs expended, net of recoveries [Member]	Sep. 30, 2011 Enviromental remediation costs liability for future expenditures [Member]	Sep. 30, 2010 Enviromental remediation costs liability for future expenditures [Member]	Sep. 30, 2011 Maximum [Member]	Sep. 30, 2011 Minimum [Member]
Site Contingency [Line Items]
Operating Leases, Future Minimum Payments Due, Current							$ 2,300,000
Site Contingency, Recovery from Third Party of Environmental Remediation Cost							20,000,000	17,700,000
Regulatory assets	434,185,000	454,601,000	75,646,000	75,707,000	182,900,000	201,600,000
Litigation Settlement, Gross							278,500,000	161,500,000
Operating Leases, Future Minimum Payments, Due Thereafter							$ 5,700,000