Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales	$ 19,842	$ 21,707
Cost of goods sold	16,411	13,288
Gross profit	3,431	8,419
Operating expenses:
Selling expenses	3,002	2,461
General and administrative	5,004	4,236
Research and development	3,066	2,576
Total operating expenses	11,072	9,273
Gain on building sale	7,175
Loss from operations	(466)	(854)
Interest expense, net	(261)	(562)
Loss before income taxes	(727)	(1,416)
Benefit for income taxes	15	(77)
Net loss	$ (742)	$ (1,339)
Net loss per share, basic and diluted	$ (0.08)	$ (0.15)
Weighted average shares outstanding, basic and diluted	9,603	8,899
Statements of Comprehensive Loss
Net loss	$ (742)	$ (1,339)
Changes in accumulated unrealized pension losses, net of taxes	(53)	22
Comprehensive loss	$ (795)	$ (1,317)