Property, Plant and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	$ 187,861		$ 185,495
Less accumulated depreciation and amortization, including accumulated amortization of capitalized leases	84,353		81,522
Total property, plant and equipment, net	103,508		103,973
Tangible Asset Impairment Charges	0	$ 0
Depreciation and amortization	3,282	$ 3,727
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	14,834		14,826
Improvements To Land And Leaseholds [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	17,404		17,408
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	33,986		33,910
Machinery And Equipment, Including Equipment Under Capitalized Leases [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	119,582		118,060
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	$ 2,055		$ 1,291