Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments and Hedging Activities (Contingent Consideration Arrangement) (Details)

v3.19.2
Derivative Instruments and Hedging Activities (Contingent Consideration Arrangement) (Details)
$ in Thousands
6 Months Ended
Jun. 30, 2019
USD ($)
$ / bbl
Jun. 30, 2018
USD ($)
Dec. 31, 2018
USD ($)
Derivative [Line Items]      
Contingent consideration arrangement $ 8,512 $ 0  
Aggregate Settlements Limit 60,000    
Year of Potential Settlement 2019      
Derivative [Line Items]      
Fair Value $ 2,485    
Threshold | $ / bbl 65    
Year of Potential Settlement 2019 | Minimum      
Derivative [Line Items]      
Contingent Payment Amount $ 9,000    
Threshold | $ / bbl 60    
Year of Potential Settlement 2019 | Maximum      
Derivative [Line Items]      
Contingent Payment Amount $ 20,833    
Threshold | $ / bbl 65    
Year of Potential Settlement 2020      
Derivative [Line Items]      
Fair Value $ 5,085    
Threshold | $ / bbl 65    
Year of Potential Settlement 2020 | Minimum      
Derivative [Line Items]      
Contingent Payment Amount $ 9,000    
Threshold | $ / bbl 60    
Year of Potential Settlement 2020 | Maximum      
Derivative [Line Items]      
Contingent Payment Amount $ 20,833    
Threshold | $ / bbl 65    
Year of Potential Settlement 2021      
Derivative [Line Items]      
Fair Value $ 4,255    
Threshold | $ / bbl 65    
Potential reduction in settlements $ 18,334    
Year of Potential Settlement 2021 | Minimum      
Derivative [Line Items]      
Contingent Payment Amount $ 9,000    
Threshold | $ / bbl 60    
Year of Potential Settlement 2021 | Maximum      
Derivative [Line Items]      
Contingent Payment Amount $ 20,833    
Threshold | $ / bbl 65    
Not Designated as Hedging Instrument      
Derivative [Line Items]      
Contingent consideration arrangement $ 24,843   $ 65,114
Fair value of derivatives - Non-current | Not Designated as Hedging Instrument      
Derivative [Line Items]      
Contingent consideration arrangement 2,339    
Fair value of derivatives - Non-current | Contingent consideration arrangement | Not Designated as Hedging Instrument      
Derivative [Line Items]      
Contingent consideration arrangement $ 9,340