FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Jun. 30, 2015

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The tables below present information about the Company's financial assets and liabilities measured and recorded at fair value on a recurring basis and indicate the fair value hierarchy of the inputs utilized to determine the fair values as of June 30, 2015 and December 31, 2014.

We have elected to offset the fair value amounts recognized for multiple derivative contracts executed with the same counterparty; however, fair value amounts by hierarchy level are presented on a gross basis in the tables below. We have posted cash margin with various counterparties to support hedging and trading activities. The cash margin posted is required by counterparties as collateral deposits and cannot be offset against the fair value of open contracts except in the event of default. We have no derivative contracts that are subject to master netting arrangements that are reflected gross on the balance sheet.

	As of June 30, 2015
	Fair Value Hierarchy						Total Gross Fair Value		Effect of Counter-party Netting		Net Carrying Value on Balance Sheet
	Level 1		Level 2		Level 3
Assets:
Money market funds	$	365,371	$	—	$	—	$	365,371	N/A		$	365,371
Non-qualified pension plan assets	5,398		—		—		5,398		N/A		5,398
Commodity contracts	65,997		14,814		2,564		83,375		(66,126	)	17,249
Derivatives included with intermediation agreement obligations	—		10,260		—		10,260		—		10,260
Liabilities:
Commodity contracts	59,827		7,050		659		67,536		(66,126	)	1,410
Catalyst lease obligations	—		32,571		—		32,571		—		32,571
Derivatives included with inventory supply arrangement obligations	—		378		—		378		—		378

	As of December 31, 2014
	Fair Value Hierarchy						Total Gross Fair Value		Effect of Counter-party Netting		Total
	Level 1		Level 2		Level 3
Assets:
Money market funds	$	5,575	$	—	$	—	$	5,575	N/A		$	5,575
Non-qualified pension plan assets	5,494		—		—		5,494		N/A		5,494
Commodity contracts	415,023		12,093		1,715		428,831		(397,676	)	31,155
Derivatives included with inventory intermediation agreement obligations	—		94,834		—		94,834		—		94,834
Derivatives included with inventory supply arrangement obligation	—		4,251		—		4,251		—		4,251
Liabilities:
Commodity contracts	390,144		7,338		194		397,676		(397,676	)	—
Catalyst lease obligations	—		36,559		—		36,559		—		36,559

Schedule of Effect of Significant Unobservable Inputs

The table below summarizes the changes in fair value measurements categorized in Level 3 of the fair value hierarchy:

	Three Months Ended June 30,						Six Months Ended June 30,
	2015			2014			2015			2014
Balance at beginning of period	$	9,678		$	(3,751	)	$	1,521		$	(23,365	)
Purchases	—			—			—			—
Settlements	(10,111		)	4,972			(11,311		)	3,667
Unrealized gain included in earnings	2,338			1,468			11,695			22,387
Transfers into Level 3	—			—			—			—
Transfers out of Level 3	—			—			—			—
Balance at end of period	$	1,905		$	2,689		$	1,905		$	2,689

Schedule of Fair value of Debt

The table below summarizes the fair value and carrying value of debt as of June 30, 2015 and December 31, 2014.

	June 30, 2015				December 31, 2014
	Carrying value		Fair  value		Carrying  value		Fair value
Senior Secured Notes (a)	$	669,070	$	687,850	$	668,520	$	675,580
Revolving Loan (b)	—		—		—		—
Rail Facility (b)	43,393		43,393		37,270		37,270
Catalyst leases (c)	32,571		32,571		36,559		36,559
	745,034		763,814		742,349		749,409
Less - Current maturities	—		—		—		—
Long-term debt	$	745,034	$	763,814	$	742,349	$	749,409

(a) The estimated fair value, categorized as a Level 2 measurement, was calculated based on the present value of future expected payments utilizing implied current market interest rates based on quoted prices of the Senior Secured Notes.

(b) The estimated fair value approximates carrying value, categorized as a Level 2 measurement, as these borrowings bear interest based upon short-term floating market interest rates.

(c) Catalyst leases are valued using a market approach based upon commodity prices for similar instruments quoted in active markets and are categorized as a Level 2 measurement. The Company has elected the fair value option for accounting for its catalyst lease repurchase obligations as the Company's liability is directly impacted by the change in fair value of the underlying catalyst.