Annual report pursuant to Section 13 and 15(d)

Reportable Segments - Operations by Industry Segment (Detail)

v3.3.1.900
Reportable Segments - Operations by Industry Segment (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Segment Reporting Information [Line Items]      
Total identifiable assets $ 1,161,186 $ 1,333,690  
Capital expenditures:      
Total capital expenditures 88,197 179,513 $ 155,645
Depreciation and amortization:      
Total depreciation and amortization 156,194 145,121 134,053
Assets 1,376,904 1,520,659  
U.S. (Lower 48) Drilling [Member]      
Segment Reporting Information [Line Items]      
Total identifiable assets 102,121 124,701  
Capital expenditures:      
Total capital expenditures 2,731 43,120 23,796
Depreciation and amortization:      
Total depreciation and amortization 22,420 21,260 15,212
International & Alaska Drilling [Member]      
Segment Reporting Information [Line Items]      
Total identifiable assets 629,784 764,794  
Capital expenditures:      
Total capital expenditures 13,458 26,761 40,822
Depreciation and amortization:      
Total depreciation and amortization 64,539 59,684 62,988
Rental Tools [Member]      
Segment Reporting Information [Line Items]      
Total identifiable assets 429,281 444,195  
Capital expenditures:      
Total capital expenditures 67,189 95,340 76,928
Depreciation and amortization:      
Total depreciation and amortization 69,235 64,177 55,853
Corporate and other [Member]      
Segment Reporting Information [Line Items]      
Total identifiable assets 215,718 186,969  
Capital expenditures:      
Total capital expenditures 4,819 14,292 14,099
Depreciation and amortization:      
Total depreciation and amortization $ 7,477 $ 5,009 $ 3,464
Exxon Neftegas Limited (ENL) [Member]      
Segment Reporting Information [Line Items]      
Percent of total revenues   18.70% 15.60%