Condensed Consolidated Statements of Operations (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenues	$ 16,070,000	$ 13,548,000	$ 40,708,000	$ 31,780,000
Costs and expenses:
Cost of sales	10,654,000	8,498,000	26,545,000	19,383,000
Selling, general and administrative	4,105,000	4,968,000	13,789,000	16,045,000
Restructuring charge	0	0	0	119,000
Research and development	265,000	216,000	814,000	780,000
Intangible assets abandonment and building impairment	0	0	317,000	2,965,000
Costs and expenses:	15,024,000	13,682,000	41,465,000	39,292,000
Operating income (loss) from continuing operations	1,046,000	(134,000)	(757,000)	(7,512,000)
Interest income	1,000	2,000	3,000	8,000
Other expense	8,000	(41,000)	(59,000)	(45,000)
Income (loss) from continuing operations before income taxes	1,055,000	(173,000)	(813,000)	(7,549,000)
Income tax (benefit) expense	0	(5,000)	(2,000)	10,000
Net income (loss) from continuing operations	1,055,000	(178,000)	(815,000)	(7,539,000)
Loss from discontinued operations (net of income tax benefit of $0 in 2018 and 2017)	(10,000)	(239,000)	(109,000)	(2,238,000)
Net income (loss)	$ 1,045,000	$ (417,000)	$ (924,000)	$ (9,777,000)
Basic
Continuing operations (in dollars per share)	$ 0.04	$ (0.01)	$ (0.04)	$ (0.32)
Discontinued operations (in dollars per share)	0.00	(0.01)	0.00	(0.09)
Basic net loss per common share (in dollars per share)	0.04	(0.02)	(0.04)	(0.41)
Diluted
Continuing operations (in dollars per share)	0.04	(0.01)	(0.04)	(0.32)
Discontinued operations (in dollars per share)	0.00	(0.01)	0.00	(0.09)
Diluted net loss per common share (in dollars per share)	$ 0.04	$ (0.02)	$ (0.04)	$ (0.41)
Weighted-average number of common shares outstanding:
Basic (in shares)	24,171,000	24,133,000	24,162,000	23,784,000
Diluted (in shares)	24,588,000	24,133,000	24,162,000	23,784,000