FAIR VALUE MEASUREMENTS (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Sep. 30, 2012	Mar. 31, 2012
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	$ 13,922	$ 13,187	$ 17,907
NYMEX natural gas contracts- Asset	10,862	7,338	709
NYMEX gasoline and heating oil contracts- Asset	322	344	81
Total Assets	25,106	20,869	18,697
NYMEX natural gas contracts- Liabilities	339	9,563	36,437
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	(7,687)	(7,338)	(709)
NYMEX gasoline and heating oil contracts- Asset	(192)	(344)	(81)
Total Assets	(7,879)	(7,682)	(790)
NYMEX natural gas contracts- Liabilities	$ (339)	$ (9,563)	$ (36,437)