Annual report pursuant to Section 13 and 15(d)

Commitments - Additional Information (Details)

v3.3.1.900
Commitments - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Commitments [Line Items]      
Minimum future lease payments due under noncancelable operating leases, 2016 $ 1,600,000    
Minimum future lease payments due under noncancelable operating leases, 2017 1,600,000    
Minimum future lease payments due under noncancelable operating leases, 2018 1,700,000    
Minimum future lease payments due under noncancelable operating leases, 2019 1,800,000    
Minimum future lease payments due under noncancelable operating leases, thereafter 5,700,000    
Total rent expense 3,300,000 $ 3,200,000 $ 2,600,000
Security amount requirement 73,000,000    
Additional security requirements for 2016 6,000,000    
Additional security requirements for 2017 4,000,000    
Additional security requirements for 2018 5,000,000    
Additional security requirements for 2019 3,000,000    
Additional security requirements for 2020 to 2023 12,000,000    
Total security requirement $ 103,000,000    
Lease expiration date Dec. 31, 2023    
Expenses related to surety bonds $ 5,500,000 $ 4,100,000 $ 5,000,000
Other commitments 5,800,000    
Future estimated costs, 2017 5,900,000    
Future estimated costs, 2018 5,300,000    
Future estimated costs, 2019 5,000,000    
Future estimated costs, thereafter 30,400,000    
Drilling Rig Commitments      
Commitments [Line Items]      
Minimum future lease payments due under noncancelable operating leases, 2015 7,000,000    
Helix Well Containment Group      
Commitments [Line Items]      
Other commitments 2,100,000    
Future estimated costs, 2017 2,100,000    
Other commitment      
Commitments [Line Items]      
Security requirement minimum 64,000,000    
Security requirement maximum $ 94,000,000