Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies (Narrative) (Details)

v3.19.2
Commitments and Contingencies (Narrative) (Details)
$ in Thousands
1 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended
Jan. 31, 2019
USD ($)
Jun. 30, 2018
USD ($)
Jun. 30, 2019
USD ($)
$ / d
$ / bbl
item
bbl
Jun. 30, 2018
USD ($)
Dec. 31, 2018
USD ($)
Jul. 31, 2019
USD ($)
Sep. 26, 2018
USD ($)
Sep. 17, 2018
USD ($)
Commitments And Contingencies [Line Items]                
Joint owner obligation     $ 25,800          
Gross lease liabilities     37,455          
Abandonment Funding     11,550   $ 11,571      
Accrued liabilities and other     $ 19,539   14,138      
Charter fee for production up to 20,000 BOPD | $ / bbl     0.93          
Charter fee amount threshold | bbl     20,000          
Charter fee for those bbls produced in excess of 20,000 BOPD | $ / bbl     2.50          
Company's share of charter expense         10,800      
Rent expense, operating leases   $ 400   $ 900        
Number of drilled wells required by agreement | item     2          
Number of appraisal wells required by agreement | item     2          
Estimated costs of technical studies, net     $ 400          
Abandonment cost related to annual funding     61,800          
Abandonment cost related to annual funding, net     $ 19,200          
Payment of excise taxes $ 1,300              
Day rate of drilling rig contract | $ / d     75,000          
Maximum                
Commitments And Contingencies [Line Items]                
Lease terms     45 months          
Minimum                
Commitments And Contingencies [Line Items]                
Lease terms     21 months          
Potential Fees From Customs Audits [Member]                
Commitments And Contingencies [Line Items]                
Accrued liabilities and other         1,300      
Gabon                
Commitments And Contingencies [Line Items]                
Abandonment Funding     $ 11,600          
Contractual obligation               $ 21,800
Accrued liabilities, end of drilling activities, gross amount             $ 5,000  
Accrued liabilities, end of drilling activities             $ 1,700  
Abandonment funding, gross     37,400          
Loss contingency     $ 4,400          
Gabon | Subsequent Event                
Commitments And Contingencies [Line Items]                
Loss contingency           $ 4,400    
Offshore Gabon                
Commitments And Contingencies [Line Items]                
Production License Agreement Term Extended By Government     5 years          
Percentage of annual funding over seven years     12.14%          
Funding period for initial rate     7 years          
Second funding period of production license     3 years          
Percentage of annual funding over last three years     5.00%          
Funding period abandonment funding     10 years          
Number of contract extension periods | item     2          
Full Charter Payment [Member]                
Commitments And Contingencies [Line Items]                
Contractual obligation     $ 53,900   53,928      
FPSO Charter [Member]                
Commitments And Contingencies [Line Items]                
Number of extensions | item     2          
Period of charter (in years)     1 year          
Percentage of share in charter payment     31.10%          
Share in charter payment, approximate annual amount     $ 9,700          
Liabilities, guarantees' fair value     $ 200   $ 200