Annual report pursuant to Section 13 and 15(d)

Reportable Segments - Results of Operations by Reportable Segment (Parenthetical) (Detail)

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Reportable Segments - Results of Operations by Reportable Segment (Parenthetical) (Detail)
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Segment Reporting Information [Line Items]      
Number of major customer   2  
Exxon Neftegas Limited (ENL) [Member]
      
Segment Reporting Information [Line Items]      
Percent of total revenues 15.60% 12.00% 16.00%
Exxon Neftegas Limited (ENL) [Member] | International Drilling [Member]
      
Segment Reporting Information [Line Items]      
Percent of segment revenues 38.30% 27.00% 34.00%
Exxon Neftegas Limited (ENL) [Member] | Technical Services [Member]
      
Segment Reporting Information [Line Items]      
Percent of segment revenues 33.90%    
Dowell Schlumberger [Member]
      
Segment Reporting Information [Line Items]      
Percent of total revenues   10.00%  
Dowell Schlumberger [Member] | International Drilling [Member]
      
Segment Reporting Information [Line Items]      
Percent of segment revenues   24.00%