Quarterly report pursuant to Section 13 or 15(d)

General - Additional Information (Detail)

v3.4.0.3
General - Additional Information (Detail) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2016
Dec. 31, 2015
Mar. 31, 2015
Revenue, Major Customer [Line Items]      
Payments to Acquire Property, Plant, and Equipment $ 7,889   $ 33,455
Percentage accounted for under the equity method 50.00%    
Reimbursable Costs $ 19,000   $ 19,700
Deposits in domestic bank 63,800 $ 91,300  
Deposits, Foreign 46,600 44,100  
Intercompany Payables $ 0 0  
Noncontrolling Interest, Fair Value Disclosure   3,000  
Exxon Neftegas Limited [Member]      
Revenue, Major Customer [Line Items]      
Percentage of revenue from major customer 39.20%   22.90%
Reimbursement Revenue $ 18,300   $ 16,000
Concentration Risk, Other Risk 0.295   0.167
BP Exploration Alaska, Inc. [Member]      
Revenue, Major Customer [Line Items]      
Percentage of revenue from major customer 11.50%    
Reimbursement Revenue $ 92    
Concentration Risk, Other Risk 0.133    
ITS Arabia Limited [Member]      
Revenue, Major Customer [Line Items]      
Purchase Price of Remaining Noncontrolling Interest   6,750  
Intercompany Payables   $ 3,375