Consolidated Statements of Earnings - Unaudited - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Net sales	$ 113,530	$ 100,154
Cost of goods sold	75,097	65,930
Gross Margin	38,433	34,224
Selling, general and administrative expenses	17,372	15,248
Research and development expenses	6,507	6,003
Restructuring charges	1,195	777
Operating earnings	13,359	12,196
Other income (expense):
Interest expense	(541)	(684)
Interest income	482	253
Other income, net	2,004	460
Total other income	1,945	29
Earnings before income taxes	15,304	12,225
Income tax expense	3,756	3,741
Net earnings	$ 11,548	$ 8,484
Earnings per share:
Basic (in dollars per share)	$ 0.35	$ 0.26
Diluted (in dollars per share)	$ 0.34	$ 0.25
Basic weighted - average common shares outstanding (in shares):	32,975	32,802
Effect of dilutive securities (in shares)	540	560
Diluted weighted - average common shares outstanding (in shares)	33,515	33,362
Cash dividends declared per share (in dollars per share)	$ 0.04	$ 0.04