Cost related to sale of oil and gas properties.

No definition available.

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- Definition

Area of land held.

+ References

No definition available.

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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

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- Definition

Amount of gain (loss) on sale or disposal of proven and unproven oil and gas properties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&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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- Definition

The cash inflow to dispose of long-lived, physical assets and mineral interests in oil and gas properties used for normal oil and gas operations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

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Sale of Oil and Natural Gas Property Interests - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018 USD ($) a	Dec. 31, 2017 USD ($) a	Dec. 31, 2016 USD ($) a	Dec. 31, 2015 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property			$ 4,700,000
Acreage Trades [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property			1,600,000
Gain (loss) on sale of oil and gas property			$ 0
Area of land \| a			249.5
Pipelines [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property			$ 400,000
Pipelines [Member] \| Maximum [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on sale of oil and gas property			(100,000)
Mineral Interests [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property			3,900,000
Gain (loss) on sale of oil and gas property			0
Unproved Lease Properties [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property			4,800,000
Gain (loss) on sale of oil and gas property			0
Assets Held for Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cost related to sale of oil and gas properties				$ 21,800,000
Asset retirement obligations related to sale of oil and gas properties				19,100,000
Gain (loss) on sale of oil and gas property				$ 1,100,000
Assets Held for Sale [Member] \| Pipelines [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property	$ 200,000
Assets Held for Sale [Member] \| Pipelines [Member] \| Maximum [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on sale of oil and gas property	(100,000)
Asset Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property			63,800,000
Gain (loss) on sale of oil and gas property			$ (7,600,000)
Area of land \| a			9,900
Asset Sale 100 Acres [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property		$ 500,000
Gain (loss) on sale of oil and gas property		$ 0
Area of land \| a		100
Asset Sale 150 Acres [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property		$ 800,000
Gain (loss) on sale of oil and gas property		$ 200,000
Area of land \| a		150
Asset Sale 1,000 Acres [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property	6,000,000.0
Gain (loss) on sale of oil and gas property	$ 1,500,000
Area of land \| a	1,000
Asset Sale 400 Acres [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property	$ 3,800,000
Gain (loss) on sale of oil and gas property	$ 0
Area of land \| a	400
Asset Sale 50 Acres [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of oil and gas property	$ 300,000
Gain (loss) on sale of oil and gas property	$ 300,000
Area of land \| a	50