DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Fair Value of Each Classification of Derivative Instrument (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value
Fair value	$ (4,112)	$ 78,129
Netting balance sheet adjustment	0	0
Net Total
Derivatives, Fair Value
Fair value	(4,112)	78,129
Derivatives NOT Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	(200)	43,113
Derivatives Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	(3,912)	35,016
Total current derivative assets
Derivatives, Fair Value
Fair value	27,671	199,750
Netting balance sheet adjustment	(14,906)	(121,465)
Total current derivative assets | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	12,157	26,698
Netting balance sheet adjustment	545	(79)
Total current derivative assets | Physical index derivative contracts
Derivatives, Fair Value
Fair value	126	87
Netting balance sheet adjustment	(63)	(62)
Total current derivative assets | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	15,388	172,965
Netting balance sheet adjustment	(15,388)	(121,324)
Total current derivative assets | Net Total
Derivatives, Fair Value
Fair value	12,765	78,285
Total current derivative assets | Net Total | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	12,702	26,619
Total current derivative assets | Net Total | Physical index derivative contracts
Derivatives, Fair Value
Fair value	63	25
Total current derivative assets | Net Total | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	0	51,641
Total current derivative assets | Derivatives NOT Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	25,370	162,916
Total current derivative assets | Derivatives NOT Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	10,461	26,698
Total current derivative assets | Derivatives NOT Designated as Hedging Instruments | Physical index derivative contracts
Derivatives, Fair Value
Fair value	126	87
Total current derivative assets | Derivatives NOT Designated as Hedging Instruments | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	14,783	136,131
Total current derivative assets | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	2,301	36,834
Total current derivative assets | Derivatives Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	1,696	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
Derivatives, Fair Value
Fair value	605	36,834
Total non-current derivative assets
Derivatives, Fair Value
Fair value	502	1,057
Netting balance sheet adjustment	(75)	0
Total non-current derivative assets | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	462	1,057
Netting balance sheet adjustment	(35)	0
Total non-current derivative assets | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	40
Netting balance sheet adjustment	(40)
Total non-current derivative assets | Net Total
Derivatives, Fair Value
Fair value	427	1,057
Total non-current derivative assets | Net Total | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	427	1,057
Total non-current derivative assets | Net Total | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	0
Total non-current derivative assets | Derivatives NOT Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	502	1,057
Total non-current derivative assets | Derivatives NOT Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	462	1,057
Total non-current derivative assets | Derivatives NOT Designated as Hedging Instruments | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	40
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 non-current derivative assets | Derivatives Designated as Hedging Instruments | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	0
Total current derivative liabilities
Derivatives, Fair Value
Fair value	(31,836)	(121,975)
Netting balance sheet adjustment	14,906	121,465
Total current derivative liabilities | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	(3,650)	(535)
Netting balance sheet adjustment	(545)	79
Total current derivative liabilities | Physical index derivative contracts
Derivatives, Fair Value
Fair value	(132)	(116)
Netting balance sheet adjustment	63	62
Total current derivative liabilities | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	(28,054)	(121,324)
Netting balance sheet adjustment	15,388	121,324
Total current derivative liabilities | Net Total
Derivatives, Fair Value
Fair value	(16,930)	(510)
Total current derivative liabilities | Net Total | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	(4,195)	(456)
Total current derivative liabilities | Net Total | Physical index derivative contracts
Derivatives, Fair Value
Fair value	(69)	(54)
Total current derivative liabilities | Net Total | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	(12,666)	0
Total current derivative liabilities | Derivatives NOT Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	(25,623)	(120,157)
Total current derivative liabilities | Derivatives NOT Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	(979)	(535)
Total current derivative liabilities | Derivatives NOT Designated as Hedging Instruments | Physical index derivative contracts
Derivatives, Fair Value
Fair value	(132)	(116)
Total current derivative liabilities | Derivatives NOT Designated as Hedging Instruments | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	(24,512)	(119,506)
Total current derivative liabilities | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	(6,213)	(1,818)
Total current derivative liabilities | Derivatives Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	(2,671)	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
Derivatives, Fair Value
Fair value	(3,542)	(1,818)
Total non-current derivative liabilities
Derivatives, Fair Value
Fair value	(449)	(703)
Netting balance sheet adjustment	75	0
Total non-current derivative liabilities | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	(72)
Netting balance sheet adjustment	35
Total non-current derivative liabilities | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	(377)	(703)
Netting balance sheet adjustment	40	0
Total non-current derivative liabilities | Net Total
Derivatives, Fair Value
Fair value	(374)	(703)
Total non-current derivative liabilities | Net Total | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	(37)
Total non-current derivative liabilities | Net Total | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	(337)	(703)
Total non-current derivative liabilities | Derivatives NOT Designated as Hedging Instruments
Derivatives, Fair Value
Fair value	(449)	(703)
Total non-current derivative liabilities | Derivatives NOT Designated as Hedging Instruments | Physical fixed price derivative contracts
Derivatives, Fair Value
Fair value	(72)
Total non-current derivative liabilities | Derivatives NOT Designated as Hedging Instruments | Futures contracts for refined petroleum products
Derivatives, Fair Value
Fair value	(377)	(703)
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
Derivatives, Fair Value
Fair value	$ 0	$ 0