Fair Value Measurements - Additional Information (Detail) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Fair Value Measurements [Line Items]
Debt, fair value	$ 564,200,000	$ 594,400,000
Principal amount	$ 800,000,000	625,000,000
7.0% Senior Notes
Fair Value Measurements [Line Items]
Debt, stated interest rate	7.00%
Debt, fair value	$ 320,900,000	329,700,000
Principal amount	$ 350,000,000	350,000,000
8.75% Senior Notes
Fair Value Measurements [Line Items]
Debt, stated interest rate	8.75%
Debt, fair value	$ 243,300,000	264,700,000
Principal amount	275,000,000	275,000,000
Amended Credit Facility
Fair Value Measurements [Line Items]
Principal amount	$ 175,000,000	$ 0

Fair Value Measurements [Line Items]

No definition available.

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

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- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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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