Annual report pursuant to Section 13 and 15(d)

Reportable Segments - Operations by Industry Segment (Detail)

v2.4.0.6
Reportable Segments - Operations by Industry Segment (Detail) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Capital expenditures:      
Total capital expenditures $ 191,543 $ 190,399 $ 219,184
Depreciation and amortization:      
Total depreciation and amortization 113,017 112,136 115,030
Rental Tools [Member]
      
Capital expenditures:      
Total capital expenditures 61,958 61,702 48,872
Depreciation and amortization:      
Total depreciation and amortization 42,944 40,497 36,558
U.S. Barge Drilling [Member]
      
Capital expenditures:      
Total capital expenditures 8,808 7,339 5,315
Depreciation and amortization:      
Total depreciation and amortization 13,906 17,006 22,165
U.S. Drilling [Member]
      
Capital expenditures:      
Total capital expenditures 86,786 99,915 113,177
Depreciation and amortization:      
Total depreciation and amortization 7,011 2,223  
International Drilling [Member]
      
Capital expenditures:      
Total capital expenditures 15,240 15,011 50,482
Depreciation and amortization:      
Total depreciation and amortization 45,967 48,965 52,429
Corporate [Member]
      
Capital expenditures:      
Total capital expenditures 18,751 6,432 1,338
Corporate and other [Member]
      
Depreciation and amortization:      
Total depreciation and amortization $ 3,189 $ 3,445 $ 3,878