Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net sales
Products	$ 135,628	$ 136,169	$ 140,340
Services	13,148	13,973	16,432
Licenses	400	398	500
Total net sales	149,176	150,540	157,272
Cost of sales
Cost of products sold	71,159	74,872	77,740
Cost of services	12,585	12,395	12,150
Gross profit	65,432	63,273	67,382
Research, development, and engineering	32,886	33,590	33,582
Selling, general, and administrative	46,835	48,746	48,858
Restructuring	751	0	0
Operating income (loss)	(15,040)	(19,063)	(15,058)
Interest expense	(80)	(35)	(48)
Interest and other income, net	442	231	190
Income before income tax	(14,678)	(18,867)	(14,916)
Provision (benefit) for income taxes	450	244	(1,147)
Net income	$ (15,128)	$ (19,111)	$ (13,769)
Net income per share - basic	$ (0.55)	$ (0.67)	$ (0.49)
Number of shares used in per share computations - basic	27,429	28,437	28,106
Net income per share - diluted	$ (0.55)	$ (0.67)	$ (0.49)
Number of shares used in per share computations - diluted	27,429	28,437	28,106