Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenues	$ 45,166	$ 55,161	$ 73,664
Costs and expenses:
Cost of sales	27,144	36,367	45,107
Selling, general and administrative	20,933	25,564	30,897
Restructuring charge	119	1,428	219
Research and development	1,070	1,752	1,447
Building and intangible assets impairment	2,965	2,074	1,425
Total Costs and Expenses	52,231	67,185	79,095
Operating loss from continuing operations	(7,065)	(12,024)	(5,431)
Interest expense	0	0	(27)
Interest income	10	25	21
Other expense	(60)	(925)	(360)
Loss from continuing operations before income taxes	(7,115)	(12,924)	(5,797)
Income tax benefit (expense)	46	(1,664)	(3,757)
Net loss from continuing operations	(7,069)	(14,588)	(9,554)
Loss from discontinued operations (net of income tax benefit of $0 in 2017, 2016 and 2015)	(3,914)	(2,800)	(2,826)
Net loss from continuing operations	$ (10,983)	$ (17,388)	$ (12,380)
Basic net loss per common share
Continuing operations (in dollars per share)	$ (0.30)	$ (0.62)	$ (0.42)
Discontinued operations (in dollars per share)	(0.16)	(0.12)	(0.12)
Basic (in dollars per share)	(0.46)	(0.74)	(0.54)
Diluted net loss per common share
Continuing operations (in dollars per share)	(0.30)	(0.62)	(0.42)
Discontinued operations (in dollars per share)	(0.16)	(0.12)	(0.12)
Diluted (in dollars per share)	$ (0.46)	$ (0.74)	$ (0.54)
Weighted-average number of common shares outstanding:
Basic (in shares)	23,872	23,365	23,101
Diluted (in shares)	23,872	23,365	23,101