Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 476,434	$ 437,491
Less accumulated depreciation	(215,419)	(186,700)
Property, Plant and Equipment, Net, Excluding Capital Leased Assets	261,015	250,791
Composite mats (rental fleet)	101,968	100,543
Less accumulated depreciation - composite mats	(47,663)	(47,680)
Property, Plant and Equipment, Gross	54,305	52,863
Property, plant and equipment, net	315,320	303,654
Land [Member[
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	11,504	11,505
Buildings and improvements [Member[
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	132,322	121,967
Machinery and heavy equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	284,337	248,229
Computer hardware and software [Member[
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	33,738	30,544
Furniture, fixtures & trailers [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	5,926	5,829
Construction in progress [Member[
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 8,607	$ 19,417