Derivatives Derivatives - Schedule of Derivative Positions (Natural Gas) (Details) - Natural Gas Swaps [Member] - Not Designated as Hedging Instrument [Member] - Specialty Product [Member]	Mar. 31, 2020 $ / MMBtu	Mar. 31, 2020 MMBTU	Dec. 31, 2019 MMBTU
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	2.11	4,042,500	0
Second Quarter 2020
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	1.97	1,006,500
Third Quarter 2020
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	2.08	1,518,000
Fourth Quarter 2020
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	2.25	1,518,000