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]
Sales	$ 84,991	$ 67,211	$ 227,745	$ 205,218
Cost of sales	56,376	44,060	151,114	135,770
Gross profit	28,615	23,151	76,631	69,448
Selling, general and administrative expenses	20,701	19,992	58,804	60,221
Research & development	3,887	3,296	11,222	9,953
Restructuring	789	182	2,767	608
Other expense, net	276	321	468	249
Income (loss) from operations	2,962	(640)	3,370	(1,583)
Interest expense	135	142	346	427
Interest income	(37)	(56)	(116)	(192)
Income (loss) before income taxes	2,864	(726)	3,140	(1,818)
Income tax expense	665	657	466	666
Net Income (loss)	$ 2,199	$ (1,383)	$ 2,674	$ (2,484)
Per share data:
Basic earnings (loss) per share (in dollars per share)	$ 0.17	$ (0.11)	$ 0.21	$ (0.19)
Diluted earnings (loss) per share (in dollars per share)	0.17	(0.11)	0.21	(0.19)
Cash dividends declared per share (in dollars per share)	$ 0	$ 0.02	$ 0.04	$ 0.06