FAIR VALUE - HIERARCHY (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 149,145		$ 69,877
Available for sale equity securities - energy industry	11,786	[1]	10,672
Liabilities	96,948		86,553
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	11,786	[1]	10,672	[1]
Other	1,514	[2]	1,299	[2]
Total assets at fair value	162,445		81,848
Total liabilities at fair value	96,948		86,553
Fair Value, Measurements, Recurring [Member] | Physical Forward Commodity Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	15,313		15,426
Liabilities	26,027		30,910
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	133,832		54,451
Liabilities	70,717		55,488
Fair Value, Measurements, Recurring [Member] | Financial Derivative Contracts - Foreign Exchange [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	204		155
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	11,786	[1]	10,672	[1]
Other	1,514	[2]	1,299	[2]
Total assets at fair value	147,132		66,422
Total liabilities at fair value	70,717		55,488
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	133,832		54,451
Liabilities	70,717		55,488
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]
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	15,313		15,426
Total liabilities at fair value	26,231		31,065
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	15,313		15,426
Liabilities	26,027		30,910
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]
Liabilities	204		155
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]
Liabilities	$ 0		$ 0

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

[2] Includes various money market funds in Level 1.