Quarterly report pursuant to Section 13 or 15(d)

Contingencies - Additional Information (Details)

v3.8.0.1
Contingencies - Additional Information (Details)
$ in Thousands
 3 Months Ended
Jan. 27, 2017
USD ($)
Mar. 31, 2018
USD ($)
Mar. 31, 2017
USD ($)
claim
Dec. 31, 2017
USD ($)
May 31, 2017
USD ($)
Dec. 15, 2014
DeepwaterWell
Dec. 31, 2010
USD ($)
Loss Contingencies [Line Items]              
Number of deepwater wells abandoned | DeepwaterWell           3  
Deposit Into registry of court   $ 49,500   $ 49,500      
Loss contingency accrued amount   $ 49,500   49,500      
Additional royalty payment             $ 4,700
Payments for royalty $ 4,700            
Bond requied to post in order to appeal 7,200            
Cash collacteral required to appeal $ 6,900            
Royalty payment processing revised period   84 months          
BSEE              
Loss Contingencies [Line Items]              
Number of notices | claim     5        
Proposed civil penalties related to various incidents of noncompliance, total     $ 7,800        
Payments for civil penalty     3,300        
Maximum              
Loss Contingencies [Line Items]              
Additional royalty payment   $ 100 $ 700        
Apache Corporation | Judicial Ruling              
Loss Contingencies [Line Items]              
Amount owed to Apache under judicial decision         $ 43,200    
Prejudgment interest, attorney fees and judgment costs         $ 6,300    
Apache Corporation | Judicial Ruling | Other Noncurrent Assets              
Loss Contingencies [Line Items]              
Deposit Into registry of court   49,500   49,500      
Apache Corporation | Judicial Ruling | Other Noncurrent Liabilities              
Loss Contingencies [Line Items]              
Loss contingency accrued amount   $ 49,500   $ 49,500