Quarterly report pursuant to Section 13 or 15(d)

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

v3.7.0.1
Reportable Segments - Results of Operations by Reportable Segment (Detail) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Revenues:    
Revenues $ 98,271 $ 130,503
Operating gross margin:    
Total operating gross margin (19,745) (13,428)
General and administration expense (7,040) (9,781)
Provision for reduction in carrying value of certain assets 0  
Gain (loss) on disposition of assets, net (352) (60)
Total operating income (loss) (27,137) (23,269)
Interest expense (10,870) (11,562)
Interest income 10 7
Other 530 2,485
Income (loss) before income taxes $ (37,467) $ (32,339)
Exxon Neftegas Limited [Member]    
Segment Reporting Information [Line Items]    
Concentration Risk, Other Risk 0.257 0.295
Percentage of revenue from major customer 34.90% 39.20%
Reimbursement Revenue $ 13,000 $ 18,300
BP Exploration Alaska, Inc. [Member]    
Segment Reporting Information [Line Items]    
Percentage of revenue from major customer 11.30%  
Drilling Services [Member]    
Revenues:    
Revenues $ 64,428 90,704
Operating gross margin:    
Total operating gross margin (9,011) (3,481)
Drilling Services [Member] | U.S. Operations [Member]    
Revenues:    
Revenues 1,215 2,085
Operating gross margin:    
Total operating gross margin (7,226) (8,558)
Drilling Services [Member] | International Operations [Member]    
Revenues:    
Revenues 63,213 88,619
Operating gross margin:    
Total operating gross margin $ (1,785) $ 5,077
Drilling Services [Member] | Exxon Neftegas Limited [Member] | International Operations [Member]    
Segment Reporting Information [Line Items]    
Concentration Risk, Other Risk 0.444 0.472
Percentage of revenue from major customer 54.30% 57.80%
Drilling Services [Member] | BP Exploration Alaska, Inc. [Member] | International Operations [Member]    
Segment Reporting Information [Line Items]    
Percentage of revenue from major customer 17.60%  
Rental Tools [Member]    
Revenues:    
Revenues $ 33,843 $ 39,799
Operating gross margin:    
Total operating gross margin (10,734) (9,947)
Rental Tools [Member] | U.S. Operations [Member]    
Revenues:    
Revenues 20,231 22,555
Operating gross margin:    
Total operating gross margin (3,773) (3,949)
Rental Tools [Member] | International Operations [Member]    
Revenues:    
Revenues 13,612 17,244
Operating gross margin:    
Total operating gross margin $ (6,961) $ (5,998)