Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Net Sales	$ 134,772	$ 113,500	$ 397,851	$ 346,759
Cost of sales	93,924	86,090	275,925	263,715
Gross profit	40,848	27,410	121,926	83,044
Selling, general and administrative expenses	14,716	12,374	45,869	38,963
Loss (gain) on disposal of assets	1	6	(61)	296
Income from operations	26,131	15,030	76,118	43,785
Interest income, net	10	9	90	49
Other income (expense), net	15	(7)	20	(16)
Income before taxes	26,156	15,032	76,228	43,818
Income tax provision	5,696	742	16,111	7,380
Net income	$ 20,460	$ 14,290	$ 60,117	$ 36,438
Earnings per share:
Basic (usd per share)	$ 0.39	$ 0.27	$ 1.15	$ 0.70
Diluted (usd per share)	$ 0.38	$ 0.26	$ 1.14	$ 0.69
Weighted average shares outstanding:
Basic (in shares)	52,260,551	52,111,444	52,174,705	52,086,209
Diluted (in shares)	53,151,295	52,722,127	52,955,049	52,624,583