Quarterly report pursuant to Section 13 or 15(d)

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

v3.10.0.1
Reportable Segments - Results of Operations by Reportable Segment (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Revenues:        
Revenues $ 118,603 $ 109,607 $ 228,278 $ 207,878
Operating gross margin:        
Total operating gross margin (167) (11,016) (10,575) (30,761)
General and administrative expense (8,288) (6,503) (14,489) (13,543)
Gain (loss) on disposition of assets, net (478) (113) (135) (465)
Total operating income (loss) (8,933) (17,632) (25,199) (44,769)
Interest expense (11,197) (11,095) (22,437) (21,965)
Interest income 30 22 53 32
Other (1,191) 560 (900) 1,090
Income (loss) before income taxes (21,291) (28,145) (48,483) (65,612)
Exxon Neftegas Limited        
Operating gross margin:        
Reimbursement revenue     $ 22,600 $ 27,000
Exxon Neftegas Limited | Customer Concentration Risk | Sales Revenue, Net        
Operating gross margin:        
Percentage of revenue from major customer     26.30% 34.00%
Exxon Neftegas Limited | Customer Concentration Risk | Sales Revenue, Net Of Reimbursable Revenues        
Operating gross margin:        
Percentage of revenue from major customer     18.60% 24.60%
BP Exploration Alaska, Inc. | Customer Concentration Risk | Sales Revenue, Net        
Operating gross margin:        
Percentage of revenue from major customer       10.50%
Total Drilling Services        
Revenues:        
Revenues 56,585 65,711 $ 114,035 $ 130,138
Operating gross margin:        
Total operating gross margin (7,578) (7,316) (18,198) (16,316)
U.S. (Lower 48) Drilling        
Revenues:        
Revenues 3,283 5,042 4,637 6,257
Operating gross margin:        
Total operating gross margin (3,751) (4,528) (9,041) (11,761)
International & Alaska Drilling        
Revenues:        
Revenues 53,302 60,669 109,398 123,881
Operating gross margin:        
Total operating gross margin (3,827) (2,788) $ (9,157) $ (4,555)
International & Alaska Drilling | Exxon Neftegas Limited | Customer Concentration Risk | Sales Revenue, Net        
Operating gross margin:        
Percentage of revenue from major customer     54.90% 57.00%
International & Alaska Drilling | Exxon Neftegas Limited | Customer Concentration Risk | Sales Revenue, Net Of Reimbursable Revenues        
Operating gross margin:        
Percentage of revenue from major customer     45.40% 46.70%
International & Alaska Drilling | BP Exploration Alaska, Inc. | Customer Concentration Risk | Sales Revenue, Net Of Reimbursable Revenues        
Operating gross margin:        
Percentage of revenue from major customer       17.60%
Total Rental Tools Services        
Revenues:        
Revenues 62,018 43,896 $ 114,243 $ 77,740
Operating gross margin:        
Total operating gross margin 7,411 (3,700) 7,623 (14,445)
U.S. Rental Tools        
Revenues:        
Revenues 42,083 29,704 76,831 49,936
Operating gross margin:        
Total operating gross margin 11,302 2,988 15,530 (798)
International Rental Tools        
Revenues:        
Revenues 19,935 14,192 37,412 27,804
Operating gross margin:        
Total operating gross margin $ (3,891) $ (6,688) $ (7,907) $ (13,647)