Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Net Sales	$ 113,500	$ 112,937	$ 346,759	$ 321,607
Cost of sales	86,115	80,174	263,406	245,869
Gross profit	27,385	32,763	83,353	75,738
Selling, general and administrative expenses	12,994	13,190	37,476	36,495
Loss (gain) on disposal of assets	6	2	296	(9)
Income from operations	14,385	19,571	45,581	39,252
Interest income, net	9	36	49	171
Other (expense) income, net	(7)	5	(16)	11
Income before taxes	14,387	19,612	45,614	39,434
Income tax provision	560	5,527	7,924	9,398
Net income	$ 13,827	$ 14,085	$ 37,690	$ 30,036
Earnings per share:
Basic (usd per share)	$ 0.27	$ 0.27	$ 0.72	$ 0.57
Diluted (usd per share)	0.26	0.27	0.72	0.57
Cash dividends declared per common share (in dollars per share)	$ 0	$ 0	$ 0.16	$ 0.16
Weighted average shares outstanding:
Basic (in shares)	52,111,444	52,238,796	52,086,209	52,315,719
Diluted (in shares)	52,722,127	52,627,541	52,624,583	52,715,390