Quarterly report pursuant to Section 13 or 15(d)

General - Additional Information (Detail)

v3.7.0.1
General - Additional Information (Detail)
$ in Thousands
 3 Months Ended
Mar. 31, 2017
USD ($)
segment
Mar. 31, 2016
USD ($)
Dec. 31, 2016
USD ($)
Revenue, Major Customer [Line Items]      
Number of Reportable Segments | segment 4    
Payments to Acquire Property, Plant, and Equipment | $ $ 14,451 $ 7,889  
Percentage accounted for under the equity method 50.00%    
Reimbursable Costs | $ $ 15,300 $ 19,000  
Deposits in domestic bank | $ 110,400   $ 81,400
Deposits, Foreign | $ $ 39,400   $ 39,700
Exxon Neftegas Limited [Member]      
Revenue, Major Customer [Line Items]      
Percentage of revenue from major customer 34.90% 39.20%  
Reimbursement Revenue | $ $ 13,000 $ 18,300  
Concentration Risk, Other Risk 0.257 0.295  
BP Exploration Alaska, Inc. [Member]      
Revenue, Major Customer [Line Items]      
Percentage of revenue from major customer 11.30%    
Drilling Services [Member] | U.S. Operations [Member]      
Revenue, Major Customer [Line Items]      
Number of Reportable Segments | segment 2    
Drilling Services [Member] | International Operations [Member]      
Revenue, Major Customer [Line Items]      
Number of Reportable Segments | segment 2    
Drilling Services [Member] | International Operations [Member] | Exxon Neftegas Limited [Member]      
Revenue, Major Customer [Line Items]      
Percentage of revenue from major customer 54.30% 57.80%  
Concentration Risk, Other Risk 0.444 0.472  
Drilling Services [Member] | International Operations [Member] | BP Exploration Alaska, Inc. [Member]      
Revenue, Major Customer [Line Items]      
Percentage of revenue from major customer 17.60%    
Rental Tools [Member] | U.S. Operations [Member]      
Revenue, Major Customer [Line Items]      
Number of Reportable Segments | segment 2    
Rental Tools [Member] | International Operations [Member]      
Revenue, Major Customer [Line Items]      
Number of Reportable Segments | segment 2