Fair Value Measurements - Additional Information (Detail) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Fair Value Measurements [Line Items]
Unproved Oil and Gas Property, Successful Effort Method	$ 490,868,000	$ 468,208,000
Debt, fair value	596,000,000	594,400,000
Debt Instrument, Face Amount	$ 695,000,000	625,000,000
7.0% Senior Notes
Fair Value Measurements [Line Items]
Debt, stated interest rate	7.00%
Debt, fair value	$ 332,700,000	329,700,000
Debt Instrument, Face 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	$ 263,300,000	264,700,000
Debt Instrument, Face Amount	275,000,000	275,000,000
Amended Credit Facility
Fair Value Measurements [Line Items]
Debt Instrument, Face Amount	70,000,000	0
Lease Financing Obligation
Fair Value Measurements [Line Items]
Debt, fair value		1,800,000
Debt Instrument, Face Amount	$ 0	$ 1,859,000

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
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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))
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- Definition

Oil and Gas properties with unproved reserves under the successful effort method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 360
-Section 25
-Paragraph 3
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-URI http://asc.fasb.org/topic&trid=2145477

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