FAIR VALUE - HIERARCHY (Details) - USD ($) $ in Thousands		Mar. 31, 2016	Sep. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		$ 55,977	$ 45,087
Liabilities		67,648	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		73,444	59,475
Other	[1]	1,607	1,572
Total assets at fair value		131,028	106,134
Total liabilities at fair value		67,648	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		6,217	6,572
Liabilities		9,140	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		49,753	38,515
Liabilities		45,576	24,821
Fair Value, Measurements, Recurring [Member] | Financial Commodity Contracts - Foreign Exchange [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		7
Fair Value, Measurements, Recurring [Member] | Interest Rate Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities		12,932	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		73,444	59,475
Other	[1]	1,607	1,572
Total assets at fair value		124,804	99,562
Total liabilities at fair value		45,576	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		49,753	38,515
Liabilities		45,576	24,821
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets, (Level 1) [Member] | Financial Commodity Contracts - Foreign Exchange [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		0
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		6,224	6,572
Total liabilities at fair value		22,072	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		6,217	6,572
Liabilities		9,140	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] | Financial Commodity Contracts - Foreign Exchange [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		7
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		12,932	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] | Financial Commodity Contracts - Foreign Exchange [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		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.