Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Revenues	$ 12,596	$ 21,677	$ 45,593	$ 55,463
Costs and expenses:
Cost of sales	7,281	13,829	28,650	33,813
Selling, general and administrative	5,789	7,122	19,711	23,490
Restructuring charge	1,108	0	1,425	235
Research and development	1,302	1,521	3,582	3,375
Costs and expenses:	15,480	22,472	53,368	60,913
Operating (loss)	(2,884)	(795)	(7,775)	(5,450)
Interest expense	0	0	0	(30)
Interest income	5	3	21	17
Other expense	(254)	(100)	(738)	(261)
(Loss) before income taxes	(3,133)	(892)	(8,492)	(5,724)
Income tax benefit	114	603	208	2,410
Net (loss)	$ (3,019)	$ (289)	$ (8,284)	$ (3,314)
Net (loss) per common share:
Basic (in dollars per share)	$ (0.13)	$ (0.01)	$ (0.35)	$ (0.14)
Diluted (in dollars per share)	$ (0.13)	$ (0.01)	$ (0.35)	$ (0.14)
Weighted-average number of common shares outstanding:
Basic (in shares)	23,446	23,167	23,337	23,079
Diluted (in shares)	23,446	23,167	23,337	23,079