Derivatives - Open Derivative Contracts (Details) MMBTU in Thousands	1 Months Ended	6 Months Ended
	Jul. 31, 2020 MMBTU $ / Unit	Jun. 30, 2020 MMBTU $ / Unit
Natural Gas Price Swaps: July 2020 - October 2020
Derivative [Line Items]
Notional (MMBtu) | MMBTU		4,920
Weighted Average Fixed Price (in dollars per unit) | $ / Unit		2.14
Natural Gas Price Swaps: November 2020 - December 2020 | Subsequent Event
Derivative [Line Items]
Notional (MMBtu) | MMBTU	2,135
Weighted Average Fixed Price (in dollars per unit) | $ / Unit	2.54
Natural Gas Price Swaps: January 2021 - December 2021 | Subsequent Event
Derivative [Line Items]
Notional (MMBtu) | MMBTU	10,950
Weighted Average Fixed Price (in dollars per unit) | $ / Unit	2.61