Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Components of Property, Plant and Equipment
Land	$ 6,907	$ 7,145
Buildings and leasehold improvements	34,650	34,351
Machinery, equipment and rental tools	73,906	85,611
Equipment in progress	13,513	12,304
Furniture and fixtures	2,706	2,749
Property and equipment	150,199	161,004
Less accumulated depreciation	(71,862)	(69,091)
Property and equipment, net	78,337	91,913
Transportation equipment [Member]
Components of Property, Plant and Equipment
Property and equipment	7,208	7,462
Computer equipment and software [Member]
Components of Property, Plant and Equipment
Property and equipment	$ 11,309	$ 11,382