Derivative Instruments - Outstanding Commodity Derivatives (Details) - Natural gas (NYMEX)	3 Months Ended
Mar. 31, 2021 MMBTU $ / MMBTU
Derivative [Line Items]
Volume (in Mmbtu) \| MMBTU	13,750,000
Swaps Weighted-Average (in usd per Mmbtu)	2.74
Volume (in Mmbtu) \| MMBTU	123,750,000
Floor, Weighted-Average (in usd per Mmbtu)	2.68
Ceiling, Weighted-Average (in usd per Mmbtu)	3.03
Minimum
Derivative [Line Items]
Derivative, Floor Price	2.50
Derivative, Cap Price	2.83
Maximum
Derivative [Line Items]
Derivative, Floor Price	2.85
Derivative, Cap Price	3.80
Volume (in Mmbtu) \| MMBTU	10,700,000
Derivative, Floor Price	0
Floor, Weighted-Average (in usd per Mmbtu)	2.50
Derivative, Cap Price	0
Ceiling, Weighted-Average (in usd per Mmbtu)	2.80
Swaps Weighted-Average (in usd per Mmbtu)
Volume (in Mmbtu) \| MMBTU	21,400,000
Ceiling, Weighted-Average (in usd per Mmbtu)
Swaps Weighted-Average (in usd per Mmbtu)	2.78

- Definition

The average cap rate on a group of price risk derivatives such as caps or collars. A payment or receipt is triggered if the market rate exceeds the cap rate on the contract.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
Period Type:	instant

- Definition

The average floor rate on a group of price risk derivatives such as floors or collars. A payment or receipt is triggered if the market rate falls below the floor rate on the contract.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeAverageFloorPrice
Namespace Prefix:	us-gaap_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
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- Definition

The cap rate on a price risk derivative such as a cap or collar. A payment or receipt is triggered if the market rate exceeds the cap rate on the contract.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeCapPrice
Namespace Prefix:	us-gaap_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
Period Type:	instant

- Definition

Floor rate on a price risk derivative such as a floor or a collar. A payment or receipt is triggered if the market rate falls below the floor rate on the contract.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFloorPrice
Namespace Prefix:	us-gaap_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
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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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Data Type:	xbrli:stringItemType
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- Definition

Nominal energy measure used to calculate payments on a derivative instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeNonmonetaryNotionalAmountEnergyMeasure
Namespace Prefix:	us-gaap_
Data Type:	num:energyItemType
Balance Type:	na
Period Type:	duration

- Definition

Average fixed price related to the group of price risk swap derivatives.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeSwapTypeAverageFixedPrice
Namespace Prefix:	us-gaap_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cog_NaturalGasContractContractOneMember
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- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cog_NaturalGasContractTwoMember
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- Details

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- Details

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- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cog_NaturalGasContractThreeMember
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- Details

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