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.

No definition available.

+ Details

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- Definition

Amount of gain (loss) on sale or disposal of property, plant and equipment assets, including oil and gas property and timber property.

+ References

Reference 1: 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=98514028&loc=d3e3602-108585

+ 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=84176398&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=98514028&loc=d3e3602-108585

+ Details

Name:	us-gaap_ImpairmentOfOilAndGasProperties
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Balance Type:	debit
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- Definition

The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=cog_OilandGasPropertiesProvedandUnprovedMember
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- Details

Name:	us-gaap_StatementGeographicalAxis=cog_WestVirginiaVirginiaandOhioMember
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Name:	us-gaap_StatementGeographicalAxis=cog_EastTexasMember
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Divestitures - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		12 Months Ended
Divestitures - Narrative (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Feb. 29, 2016	Jun. 30, 2017	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Significant Acquisitions and Disposals
Gain (loss) on sale of assets					$ (11,565)	$ (1,857)	$ 3,866
Proceeds from sale of assets					115,444	50,419	7,653
Impairment of oil and gas properties and other assets					$ 482,811	$ 435,619	$ 114,875
Oil and gas properties, proved and unproved \| West Virginia, Virginia, and Ohio
Significant Acquisitions and Disposals
Gain (loss) on sale of assets	$ (11,900)
Proceeds from sale of assets	$ 41,300
Impairment of oil and gas properties and other assets			$ 68,600
Oil and gas properties, proved and unproved \| East Texas
Significant Acquisitions and Disposals
Gain (loss) on sale of assets		$ 500
Proceeds from sale of assets		$ 56,400		$ 6,300