Annual report pursuant to Section 13 and 15(d)

Derivative Instruments - Gain (Loss) on Derivative Instruments (Details)

v3.20.4
Derivative Instruments - Gain (Loss) on Derivative Instruments (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Derivative [Line Items]      
Net gain (loss) on natural gas, oil, and NGL derivatives $ 65,291 $ 208,360 $ (123,479)
Natural gas derivatives      
Derivative [Line Items]      
Net gain (loss) on natural gas, oil, and NGL derivatives 23,765 194,450 (116,130)
Oil derivatives      
Derivative [Line Items]      
Net gain (loss) on natural gas, oil, and NGL derivatives 43,510 7,035 (13,084)
NGL derivatives      
Derivative [Line Items]      
Net gain (loss) on natural gas, oil, and NGL derivatives (603) 6,632 5,735
Contingent consideration arrangement      
Derivative [Line Items]      
Net gain (loss) on natural gas, oil, and NGL derivatives $ (1,381) $ 243 $ 0