Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property Plant And Equipment Gross Abstract
Land	$ 10,635	$ 9,707
Building and Improvements	87,111	80,740
Machinery and Equipment	153,312	140,595
Construction In Progress	4,932	4,964
Property, Plant and Equipment, Gross, Total	255,990	236,006
Less: Accumulated Depreciation	(169,286)	(150,272)
Property, Plant and Equipment, Net, Total	$ 86,704	$ 85,734