Derivative Instruments - Commodity derivatives (Details)	3 Months Ended
	Mar. 31, 2020 MMBTU / d $ / MMBTU $ / gal gal bbl
Swaps | NYMEX | Three Months Ending June 30 2020
Derivative Instruments
Weighted average index price | $ / MMBTU	2.87
Swaps | NYMEX | Three Months Ending September 30 2020
Derivative Instruments
Weighted average index price | $ / MMBTU	2.48
Swaps | ARA Propane | Three Months Ending June 30 2020
Derivative Instruments
Weighted average index price | $ / MMBTU	0.65
Swaps | ARA Propane | Three Months Ending September 30 2020
Derivative Instruments
Weighted average index price | $ / gal	2.39
Swaps | FEI Propane | Three Months Ending June 30 2020
Derivative Instruments
Weighted average index price | $ / MMBTU	55.63
Swaps | Mont Belvieu Natural Gasoline Non-TET | Three Months Ending June 30 2020
Derivative Instruments
Weighted average index price | $ / MMBTU	2.80
Swaps | NYMEX-WTI | Three Months Ending June 30 2020
Derivative Instruments
Weighted average index price | $ / MMBTU	55.16
Swaps | Natural gas | Three Months Ending June 30 2020
Derivative Instruments
Notional amount (MMBtu/day)	2,400,000
Swaps | Natural gas | Year ending December 31, 2021
Derivative Instruments
Notional amount (MMBtu/day)	60,000
Swaps | Natural gas | Year ending December 31, 2022
Derivative Instruments
Notional amount (MMBtu/day)	50,000
Swaps | Natural gas | Year ending December 31, 2023
Derivative Instruments
Notional amount (MMBtu/day)	50,000
Swaps | Natural gas | NYMEX | Three Months Ending June 30 2020
Derivative Instruments
Notional amount (MMBtu/day)	2,227,500
Swaps | Natural gas | NYMEX | Three Months Ending September 30 2020
Derivative Instruments
Notional amount (MMBtu/day)	687,500
Swaps | Natural gas | FEI Propane | Three Months Ending September 30 2020
Derivative Instruments
Notional amount (MMBtu/day)	50,000
Swaps | Natural gas | Mont Belvieu Propane Non-TET | Three Months Ending June 30 2020
Derivative Instruments
Notional amount (MMBtu/day)	2,227,500
Swaps | Natural gas | Mont Belvieu Natural Gasoline Non-TET | Three Months Ending June 30 2020
Derivative Instruments
Notional amount (MMBtu/day)	2,400,000
Swaps | Natural gas liquids | ARA Propane | Three Months Ending June 30 2020
Derivative Instruments
Notional amount | bbl	10,352
Swaps | Natural gas liquids | Mont Belvieu Propane Non-TET | Three Months Ending June 30 2020
Derivative Instruments
Notional amount | bbl	10,352
Swaps | Oil | Three Months Ending June 30 2020
Derivative Instruments
Notional amount | gal	3,000
Swaps | Oil | FEI Propane | Three Months Ending June 30 2020
Derivative Instruments
Notional amount | gal	26,000
Swaps | Oil | Mont Belvieu Propane Non-TET | Three Months Ending June 30 2020
Derivative Instruments
Notional amount | gal	26,000
Swaps | Oil | NYMEX-WTI | Three Months Ending June 30 2020
Derivative Instruments
Notional amount | gal	3,000
Fixed price swap agreement
Derivative Instruments
Notional amount (MMBtu/day)	427,500
Fixed price ($/MMBtu) | $ / MMBTU	2.77