Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Sales, net	$ 10,762	$ 16,664	$ 18,142	$ 28,733
Expenses
Cost of products	6,268	11,073	11,411	19,313
Selling, general and administrative	3,521	3,497	6,964	6,560
Total expenses	9,789	14,570	18,375	25,873
Operating income (loss)	973	2,094	(233)	2,860
Other income (expense):
Interest income	10	1	18	2
Gain on available-for-sale securities	617	0	617	0
Loss on disposal of property, plant and equipment	0	0	(104)	0
Other (expense) income	(60)	7	(147)	8
Total other income	567	8	384	10
Income before income taxes	1,540	2,102	151	2,870
Income tax expense	(222)	(737)	(101)	(992)
Net income	$ 1,318	$ 1,365	$ 50	$ 1,878
Net earnings per share-basic	$ .10	$ .10	$ .00	$ 0.14
Net earnings per share-diluted	$ .10	$ .10	$ .00	$ 0.14
Weighted average shares outstanding-basic	13,785,046	13,734,286	13,759,732	13,732,424
Weighted average shares outstanding-diluted	13,814,690	13,841,208	13,902,587	13,819,700