Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments - Commodity derivatives (Details)

v3.19.2
Derivative Instruments - Commodity derivatives (Details)
$ in Thousands
6 Months Ended
Jun. 30, 2019
USD ($)
MMBTU / d
MT
$ / MMBTU
$ / bbl
bbl
Dec. 31, 2018
USD ($)
Derivatives not designated as hedges for accounting purposes | NYMEX | Three months ending September 30, 2019    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 1,575,000  
Weighted average index price ceiling price 3.30  
Weighted average index price floor price 2.50  
Derivatives not designated as hedges for accounting purposes | NYMEX | Three months ending December 31, 2019    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 1,575,000  
Weighted average index price ceiling price 3.52  
Weighted average index price floor price 2.50  
Derivatives not designated as hedges for accounting purposes | Mont Belvieu-Propane    
Derivative Instruments    
Mont Belvieu Propane index price (as a percent) 50.00%  
Derivatives not designated as hedges for accounting purposes | Natural gas liquids | Mont Belvieu-Propane    
Derivative Instruments    
Notional amount (Bbls/day) | bbl 500  
Commodity derivative    
Derivative Instruments    
Gross amounts on balance sheet | $ $ 729,664 $ 658,830
Commodity derivative | Derivatives not designated as hedges for accounting purposes    
Derivative Instruments    
Gross amounts on balance sheet | $ 13,000  
Unamortized portion of premium | $ $ 9,000  
Swaps | NYMEX | Three months ending September 30, 2019    
Derivative Instruments    
Weighted average index price 3.32  
Swaps | NYMEX | Three months ending December 31, 2019    
Derivative Instruments    
Weighted average index price 3.45  
Swaps | NYMEX | Year ending December 31, 2020    
Derivative Instruments    
Weighted average index price 2.87  
Swaps | NYMEX | Year Ending December 31, 2021    
Derivative Instruments    
Weighted average index price 2.88  
Swaps | NYMEX | Year ending December 31, 2022    
Derivative Instruments    
Weighted average index price 3.00  
Swaps | NYMEX | Year ending December 31, 2023    
Derivative Instruments    
Weighted average index price 2.91  
Swaps | Argus Butane ARA | Three months ending September 30, 2019    
Derivative Instruments    
Weighted average index price 330.25  
Swaps | Argus Butane FEI | Three months ending September 30, 2019    
Derivative Instruments    
Weighted average index price 370.00  
Swaps | Propane Argus ARA | Three months ending September 30, 2019    
Derivative Instruments    
Weighted average index price 328.17  
Swaps | Propane Argus FEI | Three months ending September 30, 2019    
Derivative Instruments    
Weighted average index price 383.41  
Swaps | NYMEX-WTI | Three months ending September 30, 2019    
Derivative Instruments    
Weighted average index price 61.83  
Swaps | NYMEX-WTI | Three months ending December 31, 2019    
Derivative Instruments    
Weighted average index price | $ / bbl 61.83  
Swaps | NYMEX-WTI | Year ending December 31, 2020    
Derivative Instruments    
Weighted average index price | $ / bbl 59.03  
Swaps | Natural gas | Three months ending September 30, 2019    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 755,000  
Swaps | Natural gas | Three months ending December 31, 2019    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 755,000  
Swaps | Natural gas | Year ending December 31, 2020    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 60,000  
Swaps | Natural gas | Year Ending December 31, 2021    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 40,000  
Swaps | Natural gas | Year ending December 31, 2022    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 60,000  
Swaps | Natural gas | Year ending December 31, 2023    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 50,000  
Swaps | Natural gas | NYMEX | Three months ending September 30, 2019    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 755,000  
Swaps | Natural gas | NYMEX | Three months ending December 31, 2019    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 755,000  
Swaps | Natural gas | NYMEX | Year ending December 31, 2020    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 2,227,500  
Swaps | Natural gas | NYMEX | Year Ending December 31, 2021    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 1,010,000  
Swaps | Natural gas | NYMEX | Year ending December 31, 2022    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 850,000  
Swaps | Natural gas | NYMEX | Year ending December 31, 2023    
Derivative Instruments    
Notional amount (MMBtu/day) | MMBTU / d 90,000  
Swaps | Natural gas liquids | Three months ending September 30, 2019    
Derivative Instruments    
Notional amount (MT/day) | MT 1,024  
Swaps | Natural gas liquids | Argus Butane ARA | Three months ending September 30, 2019    
Derivative Instruments    
Notional amount (MT/day) | MT 242  
Swaps | Natural gas liquids | Argus Butane FEI | Three months ending September 30, 2019    
Derivative Instruments    
Notional amount (MT/day) | MT 24  
Swaps | Natural gas liquids | Propane Argus ARA | Three months ending September 30, 2019    
Derivative Instruments    
Notional amount (MT/day) | MT 484  
Swaps | Natural gas liquids | Propane Argus FEI | Three months ending September 30, 2019    
Derivative Instruments    
Notional amount (MT/day) | MT 274  
Swaps | Oil | Three months ending September 30, 2019    
Derivative Instruments    
Notional amount (Bbls/day) | bbl 5,000  
Swaps | Oil | Three months ending December 31, 2019    
Derivative Instruments    
Notional amount (Bbls/day) | bbl 5,000  
Swaps | Oil | NYMEX | Three months ending September 30, 2019    
Derivative Instruments    
Notional amount (Bbls/day) | bbl 5,000  
Swaps | Oil | NYMEX | Year ending December 31, 2020    
Derivative Instruments    
Notional amount (Bbls/day) | bbl 5,000  
Swaps | Oil | NYMEX-WTI | Three months ending December 31, 2019    
Derivative Instruments    
Notional amount (Bbls/day) | bbl 5,000  
Swaps | Oil | NYMEX-WTI | Year ending December 31, 2020    
Derivative Instruments    
Notional amount (Bbls/day) | bbl 5,000