Quarterly report pursuant to Section 13 or 15(d)

Heidelberg Field - Additional Information (Details)

v3.10.0.1
Heidelberg Field - Additional Information (Details) - USD ($)
$ in Thousands
6 Months Ended
Apr. 05, 2018
Jun. 30, 2018
Business Acquisition [Line Items]    
Asset retirement obligation recognized   $ 3,597
Heidelberg Field Acquisition    
Business Acquisition [Line Items]    
Gross purchase price $ 31,100  
Net purchase price 16,600  
Letters of credit outstanding 9,400  
Asset retirement obligation recognized $ 3,600  
Purchase obligations due, year 2028  
Purchase commitment $ 19,600  
Cobalt International Energy, Inc | Heidelberg Field Acquisition    
Business Acquisition [Line Items]    
Percentage of non-operated working interest acquired 9.375%