Property, Plant, and Equipment and Assets Held for Sale - Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, plant, and equipment
Gross property, plant and equipment	$ 204,211	$ 197,020
Less: accumulated depreciation and amortization	123,927	111,962
Net property, plant, and equipment	80,284	85,058	$ 60,646
Depreciation expense	17,600	14,600	13,400
Property, plant and equipment, impairment charge			$ 3,300
Land
Property, plant, and equipment
Gross property, plant and equipment	5,669	5,669
Building and improvements
Property, plant, and equipment
Gross property, plant and equipment	$ 61,124	54,449
Building and improvements | Minimum
Property, plant, and equipment
Average Useful Life	10 years
Building and improvements | Maximum
Property, plant, and equipment
Average Useful Life	40 years
Machinery and equipment
Property, plant, and equipment
Gross property, plant and equipment	$ 128,385	126,829
Machinery and equipment | Minimum
Property, plant, and equipment
Average Useful Life	3 years
Machinery and equipment | Maximum
Property, plant, and equipment
Average Useful Life	10 years
Leaseholds improvements
Property, plant, and equipment
Gross property, plant and equipment	$ 9,033	$ 10,073
Leaseholds improvements | Minimum
Property, plant, and equipment
Average Useful Life	3 years
Leaseholds improvements | Maximum
Property, plant, and equipment
Average Useful Life	7 years