FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Jun. 30, 2016

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, 2016 and December 31, 2015.

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, 2016
	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	$	25,005	$	—	$	—	$	25,005	N/A		$	25,005
Commodity contracts	17,039		23,098		493		40,630		(26,175	)	14,455
Derivatives included with inventory intermediation agreement obligations	—		9,338		—		9,338		—		9,338
Liabilities:
Commodity contracts	21,690		4,485		—		26,175		(26,175	)	—
Catalyst lease obligations	—		36,436		—		36,436		—		36,436

	As of December 31, 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	$	631,280	$	—	$	—	$	631,280	N/A		$	631,280
Commodity contracts	63,810		31,256		3,543		98,609		(52,482	)	46,127
Derivatives included with inventory intermediation agreement obligations	—		35,511		—		35,511		—		35,511
Liabilities:
Commodity contracts	49,960		2,522		—		52,482		(52,482	)	—
Catalyst lease obligations	—		31,802		—		31,802		—		31,802

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,
	2016			2015			2016			2015
Balance at beginning of period	$	1,915		$	9,678		$	3,543		$	1,521
Purchases	—			—			—			—
Settlements	(746		)	(10,111		)	(1,003		)	(11,311		)
Unrealized gain included in earnings	(676		)	2,338			(2,047		)	11,695
Transfers into Level 3	—			—			—			—
Transfers out of Level 3	—			—			—			—
Balance at end of period	$	493		$	1,905		$	493		$	1,905

Schedule of Fair value of Debt

The table below summarizes the fair value and carrying value of debt as of June 30, 2016 and December 31, 2015.

	June 30, 2016				December 31, 2015
	Carrying value		Fair  value		Carrying  value		Fair value
Senior Secured Notes due 2020 (a)	$	670,243	$	704,783	$	669,644	$	706,246
Revolving Loan (b)	550,000		550,000		—		—
Senior Secured Notes due 2023 (a)	500,000		483,584		500,000		492,452
Rail Facility (b)	60,521		60,521		67,491		67,491
Catalyst leases (c)	36,436		36,436		31,802		31,802
	1,817,200		1,835,324		1,268,937		1,297,991
Less - Current maturities	—		—		—		—
Less - Unamortized deferred financing costs	28,330		n/a		32,217		n/a
Long-term debt	$	1,788,870	$	1,835,324	$	1,236,720	$	1,297,991

(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.