Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Net sales	$ 101,606	$ 100,570
Cost of sales	62,956	61,559
Gross margin	38,650	39,011
Selling, engineering and administration	25,181	26,205
Operating earnings	13,469	12,806
Interest expense, net	178	270
Earnings before income taxes	13,291	12,536
Provision for income taxes	4,542	4,546
Net earnings	$ 8,749	$ 7,990
Earnings per share:
Basic (in dollars per share)	$ 0.30	$ 0.28
Diluted (in dollars per share)	0.30	0.28
Dividends declared per common share (in dollars per share)	$ 0.115	$ 0.1
Shares used in computation of earnings per share:
Basic (in shares)	28,900,702	28,842,500
Impact of dilutive securities (in shares)	182,279	154,864
Diluted (in shares)	29,082,981	28,997,364