Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net sales	$ 433,947	$ 405,232	$ 383,977
Gross profit	103,533	123,397	118,080
Selling, general and administrative expenses	47,755	49,249	38,506
(Gain) loss on disposal of assets	(12)	45	(20)
Income from operations	55,790	74,103	79,594
Interest income, net	196	298	292
Other (expense) income, net	(47)	91	105
Income before taxes	55,939	74,492	79,991
Income tax provision	13,367	19,994	26,615
Net income	$ 42,572	$ 54,498	$ 53,376
Earnings per share:
Basic (usd per share)	$ 0.81	$ 1.04	$ 1.01
Diluted (usd per share)	0.81	1.03	1.00
Cash dividends declared per common share	$ 0.32	$ 0.26	$ 0.24
Weighted average shares outstanding:
Basic	52,284,616	52,572,496	52,924,398
Diluted	52,667,939	53,078,734	53,449,754
Product
Net sales	$ 433,947	$ 405,232	$ 383,977
Cost of sales	$ 330,414	$ 281,835	$ 265,897