Derivative Instruments - Commodity derivatives (Details)	6 Months Ended
	Jun. 30, 2020 MMBTU / d $ / bbl $ / MMBTU $ / gal bbl gal
Swaps | NYMEX | Six months ending December 31, 2020
Derivative Instruments
Weighted average index price | $ / MMBTU	2.87
Swaps | NYMEX | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / MMBTU	2.02
Swaps | NYMEX | Year ending December 31, 2021
Derivative Instruments
Weighted average index price | $ / MMBTU	2.80
Swaps | NYMEX | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / MMBTU	2.58
Swaps | NYMEX | Year ending December 31, 2022 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / MMBTU	2.39
Swaps | NYMEX | Year ending December 31, 2023
Derivative Instruments
Weighted average index price | $ / gal	2.38
Swaps | NYMEX | Year ending December 31, 2023 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / MMBTU	2.35
Swaps | NYMEX | Year ending December 31, 2024 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / MMBTU	2.33
Swaps | NYMEX | Three months ending March 31, 2025 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / MMBTU	2.53
Swaps | ARA Propane | Six months ending December 31, 2020
Derivative Instruments
Weighted average index price | $ / MMBTU	0.65
Swaps | ARA Propane | Year ending December 31, 2022
Derivative Instruments
Weighted average index price | $ / gal	2.44
Swaps | OPIS Propane Mt Belv Non-TET | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / gal	0.49
Swaps | OPIS Propane Mt Belv Non-TET | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / gal	0.43
Swaps | OPIS Propane Mt Belv Non-TET | Three months ending March 31, 2022 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / gal	0.43
Swaps | OPIS Natural Gasoline Mt Belv Non-TET | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / gal	0.67
Swaps | OPIS Natural Gasoline Mt Belv Non-TET | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / gal	0.71
Swaps | OPIS Natural Gasoline Mt Belv Non-TET | Three months ending March 31, 2022 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / gal	0.72
Swaps | OPIS Ethane Mt Belv | Six months ending December 31, 2020
Derivative Instruments
Weighted average index price | $ / gal	0.20
Swaps | OPIS Ethane Mt Belv | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / gal	0.20
Swaps | OPIS Ethane Mt Belv | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / gal	0.17
Swaps | OPIS Ethane Mt Belv | Three months ending March 31, 2021
Derivative Instruments
Weighted average index price | $ / MMBTU	0.20
Swaps | OPIS Ethane Mt Belv | Three months ending March 31, 2022 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / gal	0.16
Swaps | NYMEX-WTI | Six months ending December 31, 2020
Derivative Instruments
Weighted average index price | $ / MMBTU	55.63
Swaps | NYMEX-WTI | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / bbl	37.15
Swaps | NYMEX-WTI | Year ending December 31, 2021
Derivative Instruments
Weighted average index price | $ / bbl	55.16
Swaps | NYMEX-WTI | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / bbl	38.99
Swaps | NYMEX-WTI | Year ending December 31, 2022 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / bbl	40.92
Swaps | NYMEX-WTI | Year ending December 31, 2023 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / bbl	42.45
Swaps | NYMEX-WTI | Year ending December 31, 2024 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / bbl	44.02
Swaps | NYMEX-WTI | Three months ending March 31, 2025 | VIE, Martica
Derivative Instruments
Weighted average index price | $ / bbl	45.06
Swaps | Natural gas | Six months ending December 31, 2020
Derivative Instruments
Notional amount (MMBtu/day)	2,227,500
Swaps | Natural gas | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Notional amount (MMBtu/day)	40,217
Swaps | Natural gas | Year ending December 31, 2021
Derivative Instruments
Notional amount (MMBtu/day)	2,400,000
Swaps | Natural gas | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Notional amount (MMBtu/day)	41,096
Swaps | Natural gas | Year ending December 31, 2022 | VIE, Martica
Derivative Instruments
Notional amount (MMBtu/day)	38,356
Swaps | Natural gas | Year ending December 31, 2023 | VIE, Martica
Derivative Instruments
Notional amount (MMBtu/day)	35,616
Swaps | Natural gas | Year ending December 31, 2024 | VIE, Martica
Derivative Instruments
Notional amount (MMBtu/day)	23,885
Swaps | Natural gas | Three months ending March 31, 2025 | VIE, Martica
Derivative Instruments
Notional amount (MMBtu/day)	18,021
Swaps | Natural gas | NYMEX | Six months ending December 31, 2020
Derivative Instruments
Notional amount (MMBtu/day)	2,227,500
Swaps | Natural gas | NYMEX | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Notional amount (MMBtu/day)	40,217
Swaps | Natural gas | NYMEX | Year ending December 31, 2021
Derivative Instruments
Notional amount (MMBtu/day)	2,400,000
Swaps | Natural gas | NYMEX | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Notional amount (MMBtu/day)	41,096
Swaps | Natural gas | NYMEX | Year ending December 31, 2022
Derivative Instruments
Notional amount (MMBtu/day)	1,307,500
Swaps | Natural gas | NYMEX | Year ending December 31, 2022 | VIE, Martica
Derivative Instruments
Notional amount (MMBtu/day)	38,356
Swaps | Natural gas | NYMEX | Year ending December 31, 2023
Derivative Instruments
Notional amount (MMBtu/day)	150,000
Swaps | Natural gas | NYMEX | Year ending December 31, 2023 | VIE, Martica
Derivative Instruments
Notional amount (MMBtu/day)	35,616
Swaps | Natural gas | NYMEX | Year ending December 31, 2024 | VIE, Martica
Derivative Instruments
Notional amount (MMBtu/day)	23,885
Swaps | Natural gas | NYMEX | Three months ending March 31, 2025 | VIE, Martica
Derivative Instruments
Notional amount (MMBtu/day)	18,021
Swaps | Natural gas liquids | Six months ending December 31, 2020
Derivative Instruments
Notional amount | bbl	34,815
Swaps | Natural gas liquids | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Notional amount | bbl	1,856
Swaps | Natural gas liquids | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Notional amount | bbl	2,201
Swaps | Natural gas liquids | Three months ending March 31, 2022 | VIE, Martica
Derivative Instruments
Notional amount | bbl	1,015
Swaps | Natural gas liquids | ARA Propane | Six months ending December 31, 2020
Derivative Instruments
Notional amount | bbl	10,315
Swaps | Natural gas liquids | OPIS Propane Mt Belv Non-TET | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Notional amount | bbl	951
Swaps | Natural gas liquids | OPIS Propane Mt Belv Non-TET | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Notional amount | bbl	932
Swaps | Natural gas liquids | OPIS Propane Mt Belv Non-TET | Three months ending March 31, 2022 | VIE, Martica
Derivative Instruments
Notional amount | bbl	379
Swaps | Natural gas liquids | OPIS Natural Gasoline Mt Belv Non-TET | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Notional amount | bbl	288
Swaps | Natural gas liquids | OPIS Natural Gasoline Mt Belv Non-TET | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Notional amount | bbl	282
Swaps | Natural gas liquids | OPIS Natural Gasoline Mt Belv Non-TET | Three months ending March 31, 2022 | VIE, Martica
Derivative Instruments
Notional amount | bbl	115
Swaps | Natural gas liquids | OPIS Ethane Mt Belv | Six months ending December 31, 2020
Derivative Instruments
Notional amount | bbl	24,500
Swaps | Natural gas liquids | OPIS Ethane Mt Belv | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Notional amount | bbl	617
Swaps | Natural gas liquids | OPIS Ethane Mt Belv | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Notional amount | bbl	987
Swaps | Natural gas liquids | OPIS Ethane Mt Belv | Three months ending March 31, 2021
Derivative Instruments
Notional amount | bbl	18,791
Swaps | Natural gas liquids | OPIS Ethane Mt Belv | Three months ending March 31, 2022 | VIE, Martica
Derivative Instruments
Notional amount | bbl	521
Swaps | Oil | Six months ending December 31, 2020
Derivative Instruments
Notional amount | gal	26,000
Swaps | Oil | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Notional amount | gal	118
Swaps | Oil | Year ending December 31, 2021
Derivative Instruments
Notional amount | gal	3,000
Swaps | Oil | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Notional amount | gal	94
Swaps | Oil | Year ending December 31, 2022 | VIE, Martica
Derivative Instruments
Notional amount | gal	66
Swaps | Oil | Year ending December 31, 2023 | VIE, Martica
Derivative Instruments
Notional amount | gal	52
Swaps | Oil | Year ending December 31, 2024 | VIE, Martica
Derivative Instruments
Notional amount | gal	43
Swaps | Oil | Three months ending March 31, 2025 | VIE, Martica
Derivative Instruments
Notional amount | gal	39
Swaps | Oil | NYMEX-WTI | Six months ending December 31, 2020
Derivative Instruments
Notional amount | gal	26,000
Swaps | Oil | NYMEX-WTI | Six months ending December 31, 2020 | VIE, Martica
Derivative Instruments
Notional amount | gal	118
Swaps | Oil | NYMEX-WTI | Year ending December 31, 2021
Derivative Instruments
Notional amount | gal	3,000
Swaps | Oil | NYMEX-WTI | Year ending December 31, 2021 | VIE, Martica
Derivative Instruments
Notional amount | gal	94
Swaps | Oil | NYMEX-WTI | Year ending December 31, 2022 | VIE, Martica
Derivative Instruments
Notional amount | gal	66
Swaps | Oil | NYMEX-WTI | Year ending December 31, 2023 | VIE, Martica
Derivative Instruments
Notional amount | gal	52
Swaps | Oil | NYMEX-WTI | Year ending December 31, 2024 | VIE, Martica
Derivative Instruments
Notional amount | gal	43
Swaps | Oil | NYMEX-WTI | Three months ending March 31, 2025 | VIE, Martica
Derivative Instruments
Notional amount | gal	39
Fixed price swap agreement
Derivative Instruments
Notional amount (MMBtu/day)	427,500
Fixed price ($/MMBtu) | $ / MMBTU	2.77