Long-Term Debt - Summary of Components of Long-Term Debt and Capital Leases by Debt Instrument (Parenthetical) (Detail) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Unamortized discount and deferred financing costs	$ 15,816	$ 17,586
Senior Secured Asset Based Revolving Credit Facility, Due 2020 [Member]
Debt Instrument [Line Items]
Debt instrument, due date	Feb. 26, 2020
Debt instrument stated percentage	2.25%
Debt instrument, description of variable rate basis	One month LIBOR
Unamortized discount and deferred financing costs	$ 4,976	5,593
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%
Unamortized discount and deferred financing costs	$ 1,314	1,407
Revenue Bonds Series 2014R-2, Due December 2044 [Member]
Debt Instrument [Line Items]
Debt instrument, due date	Dec. 01, 2044
Debt instrument stated percentage	3.125%
Unamortized discount and deferred financing costs	$ 602
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%
Unamortized discount and deferred financing costs	$ 534	566
Revenue Bonds Series 2015 Due August 2035 [Member]
Debt Instrument [Line Items]
Debt instrument, due date	Aug. 01, 2035
Debt instrument stated percentage	5.125%
Unamortized discount and deferred financing costs	$ 795	830
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%
Unamortized discount and deferred financing costs	$ 620	636
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%
Unamortized discount and deferred financing costs	$ 627	690
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	Jan. 01, 2021
Debt instrument stated percentage	7.00%
Senior Subordinated Notes Due 2019 Notes [Member]
Debt Instrument [Line Items]
Debt instrument, due date	Feb. 15, 2019
Debt instrument stated percentage	7.75%
Unamortized discount and deferred financing costs	$ 6,315	7,829
Revenue Bond Series 2013 Letter Of Credit Backed Due 2029 [Member]
Debt Instrument [Line Items]
Unamortized discount and deferred financing costs	$ 33	$ 35

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

No definition available.

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- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

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- Definition

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

+ 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)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

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.

+ 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

Amount of unamortized debt discount (premium) and debt issuance costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

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