Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenues	$ 13,548	$ 12,596	$ 31,780	$ 45,593
Costs and expenses:
Cost of sales	8,498	7,281	19,383	28,650
Selling, general and administrative	4,968	5,789	16,045	19,711
Restructuring charge	0	1,108	119	1,425
Research and development	216	672	780	1,438
Building impairment	0	0	2,965	0
Costs and expenses:	13,682	14,850	39,292	51,224
Operating loss	(134)	(2,254)	(7,512)	(5,631)
Interest income	2	5	8	21
Other expense	(41)	(254)	(45)	(738)
Loss from continuing operations before income taxes	(173)	(2,503)	(7,549)	(6,348)
Income tax benefit (expense)	(5)	114	10	208
Net loss from continuing operations	(178)	(2,389)	(7,539)	(6,140)
Loss from discontinued operations (net of income tax benefit of $0 in 2017 and 2016)	(239)	(630)	(2,238)	(2,144)
Net loss	$ (417)	$ (3,019)	$ (9,777)	$ (8,284)
Basic
Continuing operations (in dollars per share)	$ (0.01)	$ (0.10)	$ (0.32)	$ (0.26)
Discontinued operations (in dollars per share)	(0.01)	(0.03)	(0.09)	(0.09)
Basic net loss per common share (in dollars per share)	(0.02)	(0.13)	(0.41)	(0.35)
Diluted
Continuing operations (in dollars per share)	(0.01)	(0.10)	(0.32)	(0.26)
Discontinued operations (in dollars per share)	(0.01)	(0.03)	(0.09)	(0.09)
Diluted net loss per common share (in dollars per share)	$ (0.02)	$ (0.13)	$ (0.41)	$ (0.35)
Weighted-average number of common shares outstanding:
Basic (in shares)	24,133,000	23,446,000	23,784,000	23,337,000
Diluted (in shares)	24,133,000	23,446,000	23,784,000	23,337,000