DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Fair Value of Each Classification of Derivative Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value
Fair value	$ 78,129	$ 67,686
Netting Balance Sheet Adjustment	0	0
Total
Derivatives, Fair Value
Fair value	78,129	67,686
Derivatives NOT Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	43,113	36,984
Derivatives Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	35,016	30,702
Total current derivative assets
Derivatives, Fair Value
Fair value	199,750	223,171
Netting Balance Sheet Adjustment	(121,465)	(153,982)
Total current derivative assets | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	26,698	42,005
Netting Balance Sheet Adjustment	(79)	(12)
Total current derivative assets | Physical index derivative contracts
Derivatives, Fair Value
Fair value	87	112
Netting Balance Sheet Adjustment	(62)	(59)
Total current derivative assets | Futures contracts for refined petroleum products | Futures Contracts
Derivatives, Fair Value
Fair value	172,965	181,054
Netting Balance Sheet Adjustment	(121,324)	(153,911)
Total current derivative assets | Total
Derivatives, Fair Value
Fair value	78,285	69,189
Total current derivative assets | Total | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	26,619	41,993
Total current derivative assets | Total | Physical index derivative contracts
Derivatives, Fair Value
Fair value	25	53
Total current derivative assets | Total | Futures contracts for refined petroleum products | Futures Contracts
Derivatives, Fair Value
Fair value	51,641	27,143
Total current derivative assets | Derivatives NOT Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	162,916	192,469
Total current derivative assets | Derivatives NOT Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	26,698	42,005
Total current derivative assets | Derivatives NOT Designated as Hedging Instruments | Physical index derivative contracts
Derivatives, Fair Value
Fair value	87	112
Total current derivative assets | Derivatives NOT Designated as Hedging Instruments | Futures contracts for refined petroleum products | Futures Contracts
Derivatives, Fair Value
Fair value	136,131	150,352
Total current derivative assets | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	36,834	30,702
Total current derivative assets | Derivatives Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	0	0
Total current derivative assets | Derivatives Designated as Hedging Instruments | Physical index derivative contracts
Derivatives, Fair Value
Fair value	0	0
Total current derivative assets | Derivatives Designated as Hedging Instruments | Futures contracts for refined petroleum products | Futures Contracts
Derivatives, Fair Value
Fair value	36,834	30,702
Total non-current derivative assets
Derivatives, Fair Value
Fair value	1,057	2,919
Netting Balance Sheet Adjustment	0	0
Total non-current derivative assets | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	1,057	2,919
Netting Balance Sheet Adjustment	0	0
Total non-current derivative assets | Total
Derivatives, Fair Value
Fair value	1,057	2,919
Total non-current derivative assets | Total | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	1,057	2,919
Total non-current derivative assets | Derivatives NOT Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	1,057	2,919
Total non-current derivative assets | Derivatives NOT Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	1,057	2,919
Total non-current derivative assets | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	0	0
Total non-current derivative assets | Derivatives Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	0	0
Total current derivative liabilities
Derivatives, Fair Value
Fair value	(121,975)	(155,784)
Netting Balance Sheet Adjustment	121,465	153,982
Total current derivative liabilities | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	(535)	(1,502)
Netting Balance Sheet Adjustment	79	12
Total current derivative liabilities | Physical index derivative contracts
Derivatives, Fair Value
Fair value	(116)	(371)
Netting Balance Sheet Adjustment	62	59
Total current derivative liabilities | Futures contracts for refined petroleum products | Futures Contracts
Derivatives, Fair Value
Fair value	(121,324)	(153,911)
Netting Balance Sheet Adjustment	121,324	153,911
Total current derivative liabilities | Total
Derivatives, Fair Value
Fair value	(510)	(1,802)
Total current derivative liabilities | Total | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	(456)	(1,490)
Total current derivative liabilities | Total | Physical index derivative contracts
Derivatives, Fair Value
Fair value	(54)	(312)
Total current derivative liabilities | Total | Futures contracts for refined petroleum products | Futures Contracts
Derivatives, Fair Value
Fair value	0	0
Total current derivative liabilities | Derivatives NOT Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	(120,157)	(155,784)
Total current derivative liabilities | Derivatives NOT Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	(535)	(1,502)
Total current derivative liabilities | Derivatives NOT Designated as Hedging Instruments | Physical index derivative contracts
Derivatives, Fair Value
Fair value	(116)	(371)
Total current derivative liabilities | Derivatives NOT Designated as Hedging Instruments | Futures contracts for refined petroleum products | Futures Contracts
Derivatives, Fair Value
Fair value	(119,506)	(153,911)
Total current derivative liabilities | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	(1,818)	0
Total current derivative liabilities | Derivatives Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	0	0
Total current derivative liabilities | Derivatives Designated as Hedging Instruments | Physical index derivative contracts
Derivatives, Fair Value
Fair value	0	0
Total current derivative liabilities | Derivatives Designated as Hedging Instruments | Futures contracts for refined petroleum products | Futures Contracts
Derivatives, Fair Value
Fair value	(1,818)	0
Total non-current derivative liabilities
Derivatives, Fair Value
Fair value	(703)	(2,620)
Netting Balance Sheet Adjustment	0	0
Total non-current derivative liabilities | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value		(5)
Netting Balance Sheet Adjustment		0
Total non-current derivative liabilities | Futures contracts for refined petroleum products | Futures Contracts
Derivatives, Fair Value
Fair value	(703)	(2,615)
Netting Balance Sheet Adjustment	0	0
Total non-current derivative liabilities | Total
Derivatives, Fair Value
Fair value	(703)	(2,620)
Total non-current derivative liabilities | Total | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value		(5)
Total non-current derivative liabilities | Total | Futures contracts for refined petroleum products | Futures Contracts
Derivatives, Fair Value
Fair value	(703)	(2,615)
Total non-current derivative liabilities | Derivatives NOT Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	(703)	(2,620)
Total non-current derivative liabilities | Derivatives NOT Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value		(5)
Total non-current derivative liabilities | Derivatives NOT Designated as Hedging Instruments | Futures contracts for refined petroleum products | Futures Contracts
Derivatives, Fair Value
Fair value	(703)	(2,615)
Total non-current derivative liabilities | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	0	0
Total non-current derivative liabilities | Derivatives Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value		0
Total non-current derivative liabilities | Derivatives Designated as Hedging Instruments | Futures contracts for refined petroleum products | Futures Contracts
Derivatives, Fair Value
Fair value	$ 0	$ 0