Property, Plant and Equipment, net - Schedule of components of property, plant and equipment, net, excluding discontinued operations (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Components of property, plant and equipment [Abstract]
Property, plant and equipment, Gross	$ 30,950	$ 30,304
Less accumulated depreciation	(18,375)	(19,549)
Property, plant and equipment, Net	12,575	10,755
Land
Components of property, plant and equipment [Abstract]
Property, plant and equipment, Gross	199	253
Building and improvements
Components of property, plant and equipment [Abstract]
Property, plant and equipment, Gross	6,444	6,205
Rental property
Components of property, plant and equipment [Abstract]
Property, plant and equipment, Gross	2,749	5,650
Furniture and equipment
Components of property, plant and equipment [Abstract]
Property, plant and equipment, Gross	$ 21,558	$ 18,196