Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Sales	$ 78,197	$ 70,186	$ 142,754	$ 138,007
Cost of sales	51,568	46,633	94,738	91,711
Gross profit	26,629	23,553	48,016	46,296
Selling, general and administrative expenses	20,081	19,637	38,103	40,230
Research & development	3,777	3,369	7,335	6,656
Restructuring	542	226	1,978	426
Other expense (income), net	37	20	192	(72)
Income (loss) from operations	2,192	301	408	(944)
Interest expense	104	132	210	285
Interest income	(38)	(69)	(79)	(136)
Income (loss) before income taxes	2,126	238	277	(1,093)
Income tax (benefit) expense	(396)	93	(198)	8
Net Income (loss)	$ 2,522	$ 145	$ 475	$ (1,101)
Per share data:
Basic earnings (loss) per share (in dollars per share)	$ 0.20	$ 0.01	$ 0.04	$ (0.09)
Diluted earnings (loss) per share (in dollars per share)	0.20	0.01	0.04	(0.09)
Cash dividends declared per share (in dollars per share)	$ 0.02	$ 0.02	$ 0.04	$ 0.04