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Inventories (Details) - USD ($)
$ in Thousands
Mar. 31, 2017
Dec. 31, 2016
Inventory [Line Items]    
Raw materials: $ 114,770 $ 116,536
Total inventory 145,384 143,612
Drilling fluids    
Inventory [Line Items]    
Raw materials: 113,518 115,399
Mats    
Inventory [Line Items]    
Raw materials: 1,252 1,137
Finished goods 4,142 3,314
Blended drilling fluids components    
Inventory [Line Items]    
Finished goods $ 26,472 $ 23,762