Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net sales
Products	$ 181,433	$ 135,628	$ 136,169
Services	11,891	13,148	13,973
Licenses	727	400	398
Total net sales	194,051	149,176	150,540
Cost of sales
Cost of products sold	93,122	71,159	74,872
Cost of services	12,194	12,585	12,395
Gross profit	88,735	65,432	63,273
Research, development, and engineering	35,201	32,886	33,590
Selling, general, and administrative	45,412	46,835	48,746
Restructuring	0	751	0
Operating income (loss)	8,122	(15,040)	(19,063)
Interest expense	(43)	(80)	(35)
Interest and other income, net	613	442	231
Income before income tax	8,692	(14,678)	(18,867)
Provision (benefit) for income taxes	(2,545)	450	244
Net income	$ 11,237	$ (15,128)	$ (19,111)
Net income per share - basic	$ 0.42	$ (0.55)	$ (0.67)
Number of shares used in per share computations - basic	27,012	27,429	28,437
Net income per share - diluted	$ 0.41	$ (0.55)	$ (0.67)
Number of shares used in per share computations - diluted	27,333	27,429	28,437