Quarterly report pursuant to Section 13 or 15(d)

Contingencies - Additional Information (Details)

v3.5.0.2
Contingencies - Additional Information (Details)
 1 Months Ended 3 Months Ended 9 Months Ended
Aug. 31, 2016
Mar. 31, 2016
USD ($)
Order
Feb. 29, 2016
USD ($)
Order
Jan. 31, 2014
USD ($)
Mar. 31, 2014
USD ($)
Sep. 30, 2016
USD ($)
claim
Dec. 31, 2015
USD ($)
Dec. 15, 2014
USD ($)
Dec. 31, 2010
USD ($)
Loss Contingencies [Line Items]                  
Supplemental bonding required additional security by Bureau Of Ocean Energy Management   $ 101,000,000 $ 159,800,000     $ 260,800,000      
Number of supplemental bonding order | Order   3 4            
Maximum percentage of tangible net worth covered under self insurance           10.00%      
Underpayment of royalties       $ 30,000          
Under payment percentage of total royalty payments       0.0045%          
Statutory fine payment relative to underpayment         $ 2,300,000 $ 1,100,000      
Decide on underpayment case period 90 days                
Amount accrued           0 $ 0    
Insurance claims submitted for removal-of-wreck expenses           43,000,000      
Notified disallowed amount in reductions taken by ONRR                 $ 4,700,000
Proposed penalties           $ 1,000,000      
BSEE                  
Loss Contingencies [Line Items]                  
Number of notices | claim           5      
Proposed civil penalties related to various incidents of noncompliance, total           $ 8,300,000      
Payments for civil penalty           83,000      
Liberty Mutual Insurance Co                  
Loss Contingencies [Line Items]                  
Insurance claims received           5,000,000      
Revised estimate                  
Loss Contingencies [Line Items]                  
Insurance claims receivable           31,000,000      
Comprehensive General Liability policy                  
Loss Contingencies [Line Items]                  
Insurance claims received           1,000,000      
Energy Package                  
Loss Contingencies [Line Items]                  
Insurance claims received           1,000,000      
Starr Marine                  
Loss Contingencies [Line Items]                  
Insurance claims received           $ 5,000,000      
Minimum                  
Loss Contingencies [Line Items]                  
Loss contingency, range of possible loss               $ 0  
Maximum                  
Loss Contingencies [Line Items]                  
Loss contingency, range of possible loss               $ 47,200,000