Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Components of Property, Plant and Equipment
Land	$ 7,145	$ 6,780
Buildings and leasehold improvements	34,349	33,765
Machinery, equipment and rental tools	83,864	80,731
Equipment in progress	6,447	7,299
Furniture and fixtures	2,658	2,528
Property and equipment	152,408	145,274
Less accumulated depreciation	(66,573)	(59,163)
Property and equipment, net	85,835	86,111
Transportation equipment [Member]
Components of Property, Plant and Equipment
Property and equipment	7,426	6,566
Computer equipment and software [Member]
Components of Property, Plant and Equipment
Property and equipment	$ 10,519	$ 7,605