Long-term Debt - Long-term Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Sep. 06, 2016
Debt Instrument [Line Items]
Debt issuance costs, net of amortization	$ (10,685)	$ (16,183)
Long-term Debt	1,110,529	1,044,506
10% Senior Secured Toggle Notes due 2020
Debt Instrument [Line Items]
Principal	697,195	697,195
Discount, net of amortization	(8,901)	(11,955)
7¾% Senior Notes due 2019
Debt Instrument [Line Items]
Principal	17,959	17,959	$ 18,000
Premium, net of amortization	65	118
7¾% Convertible Second Lien PIK Notes due 2019
Debt Instrument [Line Items]
Principal	284,442	268,432
Accrued interest payable in kind	5,572	6,645
Discount, net of amortization	(38,748)	(61,230)
9½% Senior Notes due 2020
Debt Instrument [Line Items]
Principal	4,860	4,860	$ 4,900
Discount, net of amortization	(70)	(98)
9½% Convertible Second Lien PIK Notes due 2020
Debt Instrument [Line Items]
Principal	187,062	174,182
Accrued interest payable in kind	817	735
Discount, net of amortization	(31,844)	(38,959)
10% Senior Notes due 2020
Debt Instrument [Line Items]
Principal	$ 2,805	$ 2,805

Long term debt principal amount.

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- Definition

Payable in kind accrued interest.

+ References

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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

Amount, after accumulated amortization, of debt discount.

+ 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=64930785&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=64930739&loc=d3e28878-108400

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- Definition

Amount, after accumulated amortization, of debt premium.

+ References

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- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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

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- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ 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 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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