Represents the proceeds expected to be received on the sale of property before adjustment for closing costs.

No definition available.

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- Definition

The amount of exploratory well costs that have been capitalized for a period of one year or less after the completion of drilling.

+ References

No definition available.

+ Details

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- Definition

Ratio of the net operating income produced by an asset and its capital cost (original prices paid to buy the asset), used as an input to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

+ Details

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64862545&loc=d3e2921-110230

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 360
-Section 35
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=66906256&loc=d3e66150-109466

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

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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.

+ Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Properties and Equipment, Net - Narrative (Details) - USD ($)	1 Months Ended			12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Properties and Equipment
Impairment of oil and gas properties and other assets				$ 435,619,000	$ 114,875,000	$ 771,037,000
Capitalized exploratory well costs that have been capitalized for a period of one year or less	$ 0	$ 0	$ 10,600,000	$ 0	$ 0	$ 10,600,000
Oil and gas properties \| Significant Unobservable Inputs (Level 3)
Properties and Equipment
Capital rate			10.00%	10.00%
West Virginia and Virginia
Properties and Equipment
Impairment of oil and gas properties and other assets	435,600,000
West Virginia and Virginia \| Oil and gas properties, proved and unproved
Properties and Equipment
Sale of oil and gas properties before closing adjustments	$ 89,200,000
South Texas, East Texas and Louisiana
Properties and Equipment
Impairment of oil and gas properties and other assets		114,900,000
South Texas, East Texas and Louisiana \| Oil and gas properties, proved and unproved
Properties and Equipment
Sale of oil and gas properties before closing adjustments		$ 89,900,000
East And South Texas
Properties and Equipment
Impairment of oil and gas properties and other assets			$ 771,000,000
East And South Texas \| Oil and gas properties, proved and unproved
Properties and Equipment
Sale of oil and gas properties before closing adjustments			$ 86,500,000