Annual report pursuant to Section 13 and 15(d)

Derivative Instruments and Hedging Activities (Schedule of Gain or Loss on Derivative Contracts) (Details)

v3.20.4
Derivative Instruments and Hedging Activities (Schedule of Gain or Loss on Derivative Contracts) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]      
(Gain) loss on derivative contracts $ 27,773 $ 62,109 $ (48,544)
Not Designated as Hedging Instrument      
Derivative Instruments, Gain (Loss) [Line Items]      
(Gain) loss on derivative contracts 27,773 62,109 (48,544)
Not Designated as Hedging Instrument | Contingent consideration arrangements      
Derivative Instruments, Gain (Loss) [Line Items]      
(Gain) loss on derivative contracts 2,976 (2,315) 0
Not Designated as Hedging Instrument | Warrant liability      
Derivative Instruments, Gain (Loss) [Line Items]      
(Gain) loss on derivative contracts 55,519 0 0
Not Designated as Hedging Instrument | Commodity - Oil      
Derivative Instruments, Gain (Loss) [Line Items]      
(Gain) loss on derivative contracts (48,031) 73,313 (45,463)
Not Designated as Hedging Instrument | Commodity - Natural gas      
Derivative Instruments, Gain (Loss) [Line Items]      
(Gain) loss on derivative contracts 14,883 (8,889) (3,081)
Not Designated as Hedging Instrument | Natural gas liquids      
Derivative Instruments, Gain (Loss) [Line Items]      
(Gain) loss on derivative contracts $ 2,426 $ 0 $ 0