Quarterly report pursuant to Section 13 or 15(d)

Reportable Segments - Additional Information (Detail)

v2.4.0.8
Reportable Segments - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
segment
Jun. 30, 2013
Segment Information [Line Items]        
Gain (Loss) on Derivative Instruments, Net, Pretax $ 0 $ 17 $ 0 $ 54
Number of operating segments     5  
Exxon Neftegas Limited [Member]
       
Segment Information [Line Items]        
Percentage of revenue from major customer 17.50% 13.90% 17.90% 14.30%
Exxon Neftegas Limited [Member] | International Drilling [Member]
       
Segment Information [Line Items]        
Percentage of revenue from major customer 39.00% 37.70% 40.50%  
Exxon Neftegas Limited [Member] | Technical Services [Member]
       
Segment Information [Line Items]        
Percentage of revenue from major customer 58.40%   52.60%