Quarterly report pursuant to Section 13 or 15(d)

Derivatives and Fair Value (Narrative) (Details)

v3.19.2
Derivatives and Fair Value (Narrative) (Details)
 6 Months Ended
Jun. 30, 2019
USD ($)
$ / bbl
bbl
May 06, 2019
bbl
$ / bbl
Jun. 30, 2018
USD ($)
$ / bbl
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Barrels 500,000    
Commodity Contract, June 2018 Through June 2019 [Member]      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Derivative, average price per barrel | $ / bbl 66.70   74.00
Quantity of barrels | $     400,000
Barrels 225,130    
Derivative assets | $ $ 2,000,000.0    
Commodity Contract, July 19 Through June 2020 [Member]      
Derivative Instruments and Hedging Activities Disclosures [Line Items]      
Derivative, average price per barrel | $ / bbl 66.70 66.70  
Quantity of barrels   500,000  
Barrels 274,870    
Benchmark of liability position, with required financial actions | $ $ 10,000,000.0