Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Revenues	$ 8,491	$ 17,822
Costs and expenses:
Cost of sales	4,769	11,774
Selling, general and administrative	5,154	7,162
Restructuring charge	61	317
Research and development	1,014	1,158
Costs and expenses:	10,998	20,411
Operating loss	(2,507)	(2,589)
Interest income	3	10
Other expense	(2)	(263)
Loss before income taxes	(2,506)	(2,842)
Income tax benefit	0	205
Net loss	$ (2,506)	$ (2,637)
Net loss per common share:
Basic (in dollars per share)	$ (0.11)	$ (0.11)
Diluted (in dollars per share)	$ (0.11)	$ (0.11)
Weighted-average number of common shares outstanding:
Basic (in shares)	23,472	23,184
Diluted (in shares)	23,472	23,184