Quarterly report pursuant to Section 13 or 15(d)

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

v3.5.0.2
Reportable Segments - Results of Operations by Reportable Segment (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Revenues:        
Revenues $ 105,287 $ 185,941 $ 235,790 $ 390,017
Operating gross margin:        
Total operating gross margin (20,225) 4,021 (33,653) 28,288
General and administration expense (7,995) (9,511) (17,776) (20,348)
Provision for reduction in carrying value of certain assets 0 (2,316) 0 (2,316)
Gain (loss) on disposition of assets, net (2) (138) (62) 2,303
Total operating income (loss) (28,222) (7,944) (51,491) 7,927
Interest expense (12,187) (11,396) (23,749) (22,474)
Interest income 32 19 39 202
Other (358) (1,529) 2,127 (2,909)
Loss before income taxes (40,735) (20,850) (73,074) (17,254)
Rental Tools [Member]        
Revenues:        
Revenues 32,296 64,124 72,095 140,182
Operating gross margin:        
Total operating gross margin (14,410) 4,729 (24,356) 17,354
U.S. (Lower 48) Drilling [Member]        
Revenues:        
Revenues 1,065 6,848 3,150 20,945
Operating gross margin:        
Total operating gross margin (9,011) (7,552) (17,571) (13,274)
International & Alaska Drilling [Member]        
Revenues:        
Revenues 71,926 114,969 160,545 228,890
Operating gross margin:        
Total operating gross margin 3,196 6,844 8,274 24,208
Drilling Services [Member]        
Revenues:        
Revenues 72,991 121,817 163,695 249,835
Operating gross margin:        
Total operating gross margin $ (5,815) $ (708) $ (9,297) $ 10,934
Exxon Neftegas Limited [Member]        
Segment Reporting Information [Line Items]        
Concentration Risk, Other Risk     0.287 0.181
Percentage of revenue from major customer     39.80% 26.00%
Reimbursement Revenue     $ 36,900 $ 39,700
Exxon Neftegas Limited [Member] | International & Alaska Drilling [Member]        
Segment Reporting Information [Line Items]        
Concentration Risk, Other Risk     0.464 0.34
Percentage of revenue from major customer     58.40% 44.30%
BP Exploration Alaska, Inc. [Member]        
Segment Reporting Information [Line Items]        
Percentage of revenue from major customer     11.90%  
BP Exploration Alaska, Inc. [Member] | International & Alaska Drilling [Member]        
Segment Reporting Information [Line Items]        
Percentage of revenue from major customer     17.20%