Long-Term Debt - Components of Long-Term Debt and Capital Leases (Parenthetical) (Detail) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2015	Dec. 31, 2014
Senior Secured Asset Based Revolving Credit Facility, Due 2020 [Member]
Debt Instrument [Line Items]
Debt instrument, due date	Feb. 27, 2020
Debt instrument stated percentage	2.25%
Senior Secured Revolving Credit Facility, Due 2016 [Member]
Debt Instrument [Line Items]
Debt instrument, due date	Mar. 18, 2016
Debt instrument stated percentage	3.75%
Revenue Bonds Series 2014 Due December 2044 [Member]
Debt Instrument [Line Items]
Debt instrument, due date	Dec. 01, 2044
Debt instrument stated percentage	3.75%
Revenue Bonds Series 2005R-2, Due January 2025 [Member]
Debt Instrument [Line Items]
Debt instrument, due date	Jan. 01, 2025
Debt instrument stated percentage	6.25%
Long-Term Revenue Bonds Series 2013 Due April 2036 [Member]
Debt Instrument [Line Items]
Debt instrument, due date	Apr. 01, 2036
Debt instrument stated percentage	4.75%
Revenue Bonds Series 2013 Due April 2029 [Member]
Debt Instrument [Line Items]
Debt instrument, due date	Apr. 01, 2029
Debt instrument stated percentage	4.00%
Revenue Bonds Series, 2005R-1, Due January 2025 [Member]
Debt Instrument [Line Items]
Debt instrument, due date	Jan. 01, 2025
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Debt instrument maturity date	Apr. 01, 2023
Debt instrument stated percentage	7.70%
Notes Payable [Member]
Debt Instrument [Line Items]
Debt instrument maturity date	Apr. 01, 2017
Debt instrument stated percentage	6.00%
Senior Subordinated Notes Due 2019 Notes [Member]
Debt Instrument [Line Items]
Debt instrument, due date	Feb. 15, 2019
Debt instrument stated percentage	7.75%
Senior second lien notes, unamortized discount	$ 1,620	$ 1,319

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

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+ References

No definition available.

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- Definition

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

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Latest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

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

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

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