Quarterly report pursuant to Section 13 or 15(d)

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

v3.4.0.3
Reportable Segments - Results of Operations by Reportable Segment (Detail) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Revenues:    
Revenues $ 130,503 $ 204,076
Operating gross margin:    
Total operating gross margin (13,428) 24,267
General and administration expense (9,781) (10,837)
Gain (loss) on disposition of assets, net (60) 2,441
Total operating income (loss) (23,269) 15,871
Interest expense (11,562) (11,078)
Interest income 7 183
Other 2,485 (1,380)
Income (loss) before income taxes (32,339) 3,596
Rental Tools [Member]    
Revenues:    
Revenues 39,799 76,058
Operating gross margin:    
Total operating gross margin (9,947) 12,630
U.S. (Lower 48) Drilling [Member]    
Revenues:    
Revenues 2,085 14,097
Operating gross margin:    
Total operating gross margin (8,558) (5,717)
International & Alaska Drilling [Member]    
Revenues:    
Revenues 88,619 113,921
Operating gross margin:    
Total operating gross margin 5,077 17,354
Drilling Services [Member]    
Revenues:    
Revenues 90,704 128,018
Operating gross margin:    
Total operating gross margin $ (3,481) $ 11,637
Exxon Neftegas Limited [Member]    
Segment Reporting Information [Line Items]    
Concentration Risk, Other Risk 0.295 0.167
Percentage of revenue from major customer 39.20% 22.90%
Reimbursement Revenue $ 18,300 $ 16,000
Exxon Neftegas Limited [Member] | International & Alaska Drilling [Member]    
Segment Reporting Information [Line Items]    
Concentration Risk, Other Risk 0.472 0.323
Percentage of revenue from major customer 57.80% 41.00%
BP Exploration Alaska, Inc. [Member]    
Segment Reporting Information [Line Items]    
Concentration Risk, Other Risk 0.133  
Percentage of revenue from major customer 11.50%  
Reimbursement Revenue $ 92  
BP Exploration Alaska, Inc. [Member] | International & Alaska Drilling [Member]    
Segment Reporting Information [Line Items]    
Concentration Risk, Other Risk .209  
Percentage of revenue from major customer 16.50%