Quarterly report pursuant to Section 13 or 15(d)

General - Additional Information (Detail)

v3.8.0.1
General - Additional Information (Detail)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2017
USD ($)
Sep. 30, 2016
USD ($)
Sep. 30, 2017
USD ($)
segment
Sep. 30, 2016
USD ($)
Dec. 31, 2016
USD ($)
Revenue, Major Customer [Line Items]          
Number of Reportable Segments | segment     4    
Payments to Acquire Property, Plant, and Equipment | $     $ 44,836 $ 20,994  
Percentage accounted for under the equity method 50.00%   50.00%    
Reimbursable Costs | $ $ 15,000 $ 19,400 $ 45,500 $ 55,800  
Deposits in domestic bank | $ 84,500   84,500   $ 81,400
Deposits, Foreign | $ $ 37,500   $ 37,500   $ 39,700
Exxon Neftegas Limited [Member]          
Revenue, Major Customer [Line Items]          
Percentage of revenue from major customer     32.60% 39.60%  
Reimbursement Revenue | $     $ 39,900 $ 54,300  
Concentration Risk, Other Risk     0.236 0.28  
BP Exploration Alaska, Inc. [Member]          
Revenue, Major Customer [Line Items]          
Percentage of revenue from major customer     10.00%    
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     56.90% 58.40%  
Concentration Risk, Other Risk     0.469 0.456  
Drilling Services [Member] | International Operations [Member] | BP Exploration Alaska, Inc. [Member]          
Revenue, Major Customer [Line Items]          
Percentage of revenue from major customer     17.50%    
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