FAIR VALUE - HIERARCHY (Details) - USD ($) $ in Thousands		Jun. 30, 2016	Sep. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		$ 43,796	$ 45,087
Liabilities		106,867	38,330
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		64,377	59,475
Other	[1]	1,567	1,572
Total assets at fair value		109,740	106,134
Total liabilities at fair value		106,867	38,330
Fair Value, Measurements, Recurring [Member] | Physical Commodity Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		8,590	6,572
Liabilities		10,257	9,281
Fair Value, Measurements, Recurring [Member] | Financial Commodity Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		35,206	38,515
Liabilities		73,978	24,821
Fair Value, Measurements, Recurring [Member] | Interest Rate Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities		22,632	4,228
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		64,377	59,475
Other	[1]	1,567	1,572
Total assets at fair value		101,150	99,562
Total liabilities at fair value		73,978	24,821
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets, (Level 1) [Member] | Physical 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 Commodity Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		35,206	38,515
Liabilities		73,978	24,821
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets, (Level 1) [Member] | Interest Rate Contracts [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	0
Other	[1]	0	0
Total assets at fair value		8,590	6,572
Total liabilities at fair value		32,889	13,509
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Physical Commodity Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		8,590	6,572
Liabilities		10,257	9,281
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Financial 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 Other Observable Inputs (Level 2) [Member] | Interest Rate Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities		22,632	4,228
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	0
Other	[1]	0	0
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 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 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] | Interest Rate Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities		$ 0	$ 0

[1] Includes various money market funds.