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 6 Months Ended
Mar. 31, 2016
USD ($)
Order
Feb. 29, 2016
USD ($)
Order
Jan. 31, 2014
USD ($)
Mar. 31, 2014
USD ($)
Jun. 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            
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      
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]                
Loss contingency, range of possible loss         $ 1,000,000      
Number of notices | claim         3      
Proposed civil penalties related to various incidents of noncompliance, total         $ 7,100,000      
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             $ 43,700,000