Derivative Instruments - Outstanding Commodity Derivatives (Details) - Natural gas (NYMEX)	6 Months Ended
Jun. 30, 2020 MMBTU $ / MMBTU	Apr. 30, 2020 $ / MMBTU
Derivative [Line Items]
Volume (in Mmbtu) \| MMBTU	36,900,000
Swaps weighted-average (in usd per Mmbtu)	2.25
Volume (in Mmbtu) \| MMBTU	61,500,000
Floor, weighted-average (in usd per Mmbtu)	2.05
Ceiling, weighted-average (in usd per Mmbtu)	2.24
Minimum
Derivative [Line Items]
Floor, range (in usd per Mmbtu)		1.90
Ceiling, range (in usd per Mmbtu)	2.10
Maximum
Derivative [Line Items]
Floor, range (in usd per Mmbtu)		2.15
Ceiling, range (in usd per Mmbtu)	2.38

- 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_
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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
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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

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Data Type:	srt-types:perUnitItemType
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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

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

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Namespace Prefix:	us-gaap_
Data Type:	srt-types:perUnitItemType
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- Details

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- Details

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- Details

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