Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Sales, net	$ 7,644	$ 11,746
Expenses
Cost of products	5,207	6,909
Selling, general and administrative	4,755	4,089
Total expenses	9,962	10,998
Operating (loss) income	(2,318)	748
Other income (expense):
Interest income	55	17
Gain (loss) on investment in securities	592	(1,146)
Gain on disposal of property, plant and equipment	3	0
Other expense	(5)	(168)
Total other income (expense)	645	(1,297)
Loss before income taxes	(1,673)	(549)
Income tax benefit	355	106
Net loss	$ (1,318)	$ (443)
Net earnings per share-basic	$ (0.10)	$ (0.03)
Net earnings per share-diluted	$ (0.10)	$ (0.03)
Weighted average shares outstanding-basic	12,761,713	13,754,119
Weighted average shares outstanding-diluted	12,761,713	13,754,119