FAIR VALUE - HIERARCHY (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Sep. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 47,452		$ 56,088
Available for sale equity securities - energy industry	11,200	[1]	11,700
Liabilities	76,415		42,848
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale equity securities - energy industry	11,218	[1]	11,716	[1]
Other	1,263	[2]	1,129	[2]
Total assets at fair value	59,933		68,933
Total liabilities at fair value	76,415		42,848
Fair Value, Measurements, Recurring [Member] | Physical Forward Commodity Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	5,832		11,823
Liabilities	35,680		14,595
Fair Value, Measurements, Recurring [Member] | Financial Derivative Contracts - Natural Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	41,620		44,249
Liabilities	40,451		28,248
Fair Value, Measurements, Recurring [Member] | Financial Derivative Contracts - Foreign Exchange [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0		16
Liabilities	284		5
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets, (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale equity securities - energy industry	11,218	[1]	11,716	[1]
Other	1,263	[2]	1,129	[2]
Total assets at fair value	54,101		57,094
Total liabilities at fair value	40,451		28,248
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets, (Level 1) [Member] | Physical Forward Commodity Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0		0
Liabilities	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets, (Level 1) [Member] | Financial Derivative Contracts - Natural Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	41,620		44,249
Liabilities	40,451		28,248
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets, (Level 1) [Member] | Financial Derivative Contracts - Foreign Exchange [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0		0
Liabilities	0		0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale equity securities - energy industry	0	[1]	0	[1]
Other	0	[2]	0	[2]
Total assets at fair value	5,832		11,839
Total liabilities at fair value	35,964		14,600
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Physical Forward Commodity Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	5,832		11,823
Liabilities	35,680		14,595
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Financial Derivative Contracts - Natural Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0		0
Liabilities	0		0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Financial Derivative Contracts - Foreign Exchange [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0		16
Liabilities	284		5
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale equity securities - energy industry	0	[1]	0	[1]
Other	0	[2]	0	[2]
Total assets at fair value	0		0
Total liabilities at fair value	0		0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Physical Forward Commodity Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0		0
Liabilities	0		0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Financial Derivative Contracts - Natural Gas [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0		0
Liabilities	0		0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Financial Derivative Contracts - Foreign Exchange [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0		0
Liabilities	$ 0		$ 0

[1] Included in Other noncurrent assets on the Unaudited Condensed Consolidated Balance Sheets

[2] Includes various money market funds.