DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES Part 3 (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Sep. 30, 2012	Mar. 31, 2012
Derivatives, Fair Value [Line Items]
Liabilities Fair Value	$ 339	$ 9,563	$ 36,437
Asset Derivatives Fair Value	11,184	7,682	790
Not Designated as Hedging Instrument [Member] | NYMEX Natural Gas Contracts [Member] | Accounts Receivable - Other [Member]
Derivatives, Fair Value [Line Items]
Liabilities Fair Value		9,563	36,437
Asset Derivatives Fair Value		7,338	709
Not Designated as Hedging Instrument [Member] | NYMEX Natural Gas Contracts [Member] | Derivative Instruments Assets [Member]
Derivatives, Fair Value [Line Items]
Liabilities Fair Value	339
Asset Derivatives Fair Value	10,862
Not Designated as Hedging Instrument [Member] | NYMEX Gasoline and Heating Oil Contracts [Member] | Accounts Receivable - Other [Member]
Derivatives, Fair Value [Line Items]
Liabilities Fair Value	0	0	0
Asset Derivatives Fair Value		10	9
Not Designated as Hedging Instrument [Member] | NYMEX Gasoline and Heating Oil Contracts [Member] | Derivative Instruments Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	10
Designated as Hedging Instrument [Member] | NYMEX Gasoline and Heating Oil Contracts [Member] | Accounts Receivable - Other [Member]
Derivatives, Fair Value [Line Items]
Liabilities Fair Value	0	0	0
Asset Derivatives Fair Value		334	72
Designated as Hedging Instrument [Member] | NYMEX Gasoline and Heating Oil Contracts [Member] | Derivative Instruments Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	$ 312