Assets - Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Property, plant, and equipment
Gross property, plant and equipment	$ 193,524	$ 197,020
Less: accumulated depreciation and amortization	110,424	111,962
Net property, plant, and equipment	83,100	85,058
Depreciation expense	4,200	2,900
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	59,972	54,449
Machinery and equipment
Property, plant, and equipment
Gross property, plant and equipment	118,360	126,829
Leaseholds improvements
Property, plant, and equipment
Gross property, plant and equipment	$ 9,523	$ 10,073