FAIR VALUE MEASUREMENTS (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U. S. Stock/Bond Mutual Funds	$ 13,146	$ 13,187	$ 15,916
NYMEX natural gas contracts- Asset	1,726	7,338	8
NYMEX gasoline and heating oil contracts- Asset	281	344	31
Total Assets	15,153	20,869	15,955
NYMEX natural gas contracts- Liabilities	6,162	9,563	26,349
Significant Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U. S. Stock/Bond Mutual Funds	0	0	0
NYMEX natural gas contracts- Asset	0	0	0
NYMEX gasoline and heating oil contracts- Asset	0	0	0
Total Assets	0	0	0
NYMEX natural gas contracts- Liabilities	0	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U. S. Stock/Bond Mutual Funds	0	0	0
NYMEX natural gas contracts- Asset	0	0	0
NYMEX gasoline and heating oil contracts- Asset	0	0	0
Total Assets	0	0	0
NYMEX natural gas contracts- Liabilities	0	0	0
Effects of Netting and Cash Margin Receivables Payables [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U. S. Stock/Bond Mutual Funds	0	0	0
NYMEX natural gas contracts- Asset	(1,726)	(7,338)	(8)
NYMEX gasoline and heating oil contracts- Asset	(281)	(344)	(31)
Total Assets	(2,007)	(7,682)	(39)
NYMEX natural gas contracts- Liabilities	$ (6,162)	$ (9,563)	$ (26,349)