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Additional draw down available under the indenture.

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Debt Instrument Borrowing Base

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Debt instrument repurchase amount per unit.

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Cash outflow associated with the settlement of an interest rate swap not designated as an effective hedge.

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Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities.

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Fair value amount of debt instrument that was repurchased.

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The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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The noncurrent cash, cash equivalents and investments that is restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits classified as long-term; that is not expected to be released from such existing restrictions within one year of the balance sheet date or operating cycle, whichever is longer. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. Includes noncurrent cash equivalents and investments that are similarly restricted as to withdrawal, usage or disposal.

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Long-Term Debt - Additional Information (Detail) $ in Thousands	1 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2015 USD ($) $ / NotesPayable	Feb. 28, 2015 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Debt Instrument [Line Items]
Restricted cash reserved for repayment of capital projects	$ 5,283		$ 5,283	$ 5,283	$ 6,632
Revolver borrowings	531,745		531,745	531,745	535,711
Cash payment for settlement of interest rate derivative		$ 830
Loss on debt extinguishment			345	866
Senior Subordinated Notes Due 2019 Notes [Member]
Debt Instrument [Line Items]
Carrying value of bonds	$ 375,300		$ 375,300	$ 375,300
Debt instrument stated percentage	7.75%	7.75%	7.75%	7.75%
Maturity date		Feb. 15, 2019		Feb. 15, 2019
Issued discount	$ 1,486	$ 476	$ 1,486	$ 1,486	1,319
Revolver borrowings	373,814		373,814	373,814	$ 323,681
Aggregate principal repurchase amount	$ 9,700		9,700	$ 9,700
Repurchase price per debt instrument \| $ / NotesPayable	101.25
Loss on debt extinguishment			345
Senior Secured Revolving Credit Facility Due 2016 [Member]
Debt Instrument [Line Items]
Maturity date		Mar. 18, 2016
Senior Secured Asset Based Revolving Credit Facility, Due 2020 [Member]
Debt Instrument [Line Items]
Maturity date				Feb. 26, 2020
Revolving credit facility	$ 190,000		190,000	$ 190,000
Additional increase in credit facility	100,000		100,000	$ 100,000
Line of credit facility interest rate description				LIBOR plus between 1.75% and 2.50%
Debt instrument stated percentage				2.25%
Maturity date description				The ABL Facility matures on February 26, 2020. If we fail to refinance the 2019 Notes on or before November 16, 2018, the maturity date for the ABL Facility shall be November 16, 2018.
Borrowing base	147,115		147,115	$ 147,115
Available revolving credit facility	57,252		57,252	57,252
Revolver borrowings	62,900		62,900	62,900
Outstanding irrevocable letters of credit totaling	26,963		26,963	$ 26,963
Senior Secured Asset Based Revolving Credit Facility, Due 2020 [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument stated percentage				1.75%
Senior Secured Asset Based Revolving Credit Facility, Due 2020 [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument stated percentage				2.50%
Revenue Bonds Series 2015 Due August 2035 [Member]
Debt Instrument [Line Items]
Carrying value of bonds	$ 15,000		$ 15,000	$ 15,000
Debt instrument stated percentage	5.125%		5.125%	5.125%
Additional bond issued	$ 15,000		$ 15,000	$ 15,000
Maturity date				Aug. 01, 2035
Restricted cash reserved for repayment of capital projects	4,500		4,500	$ 4,500
Revolver borrowings	$ 15,000		$ 15,000	15,000
Senior Secured Revolving Credit Facility Due 2016 [Member] \| Write off Deferred Financing Costs [Member]
Debt Instrument [Line Items]
Loss on debt extinguishment				$ 521
Subsequent Issuance of Senior Subordinated Notes [Member] \| Senior Subordinated Notes Due 2019 Notes [Member]
Debt Instrument [Line Items]
Issuance of senior subordinated notes, face amount		$ 60,000
Original Issuance of Senior Subordinated Notes [Member] \| Senior Subordinated Notes Due 2019 Notes [Member]
Debt Instrument [Line Items]
Issuance of senior subordinated notes, face amount		$ 325,000