Fair Value Measurements [Line Items]

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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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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- Definition

The expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties as the estimate of future successful production from these properties is reduced.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
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- Definition

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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
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-URI http://asc.fasb.org/topic&trid=2145477

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Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Fair Value Measurements [Line Items]
Unproved Oil and Gas Property, Successful Effort Method	$ 657,541,000		$ 657,541,000		$ 84,676,000
Debt, fair value	$ 638,800,000		638,800,000		661,400,000
Impairment of Oil and Gas Properties			$ 0
7.0% Senior Notes
Fair Value Measurements [Line Items]
Debt, stated interest rate	7.00%		7.00%
Debt, fair value	$ 348,600,000		$ 348,600,000		356,100,000
8.75% Senior Notes
Fair Value Measurements [Line Items]
Debt, stated interest rate	8.75%		8.75%
Debt, fair value	$ 290,200,000		$ 290,200,000		305,300,000
Amended Credit Facility
Fair Value Measurements [Line Items]
Debt, fair value	0		0
Lease Financing Obligation
Fair Value Measurements [Line Items]
Debt, fair value	1,800,000		1,800,000		2,100,000
Uinta Basin [Member]
Fair Value Measurements [Line Items]
Impairment of Oil and Gas Properties					37,945,000
DJ Basin, non-core [Member]
Fair Value Measurements [Line Items]
Impairment of Oil and Gas Properties					2,100,000
Unproved Oil And Gas Properties
Fair Value Measurements [Line Items]
Impairment of Oil and Gas Properties	$ 0	$ 0	$ 0	$ 8,010,000
Piceance [Member]
Fair Value Measurements [Line Items]
Impairment of Oil and Gas Properties					$ 9,100,000