Consolidated Statements of Comprehensive 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	$ 194,551	$ 166,380	$ 580,575	$ 544,279
Cost of sales	112,120	99,170	345,334	309,241
Gross profit	82,431	67,210	235,241	235,038
Selling, general and administrative expenses	27,409	28,132	93,281	90,603
Income from operations	55,022	39,078	141,960	144,435
Interest (income) expense, net	(744)	(222)	(801)	377
Income before income taxes	55,766	39,300	142,761	144,058
Provision for income taxes	13,790	9,829	33,520	34,657
Net income	$ 41,976	$ 29,471	$ 109,241	$ 109,401
Basic earnings per common share	$ 0.72	$ 0.50	$ 1.87	$ 1.86
Basic weighted average common shares outstanding	58,401,183	58,741,973	58,476,430	58,785,546
Diluted earnings per common share	$ 0.72	$ 0.50	$ 1.86	$ 1.85
Diluted weighted average common shares outstanding	58,605,726	59,084,117	58,706,960	59,111,303
Comprehensive income	$ 41,976	$ 29,471	$ 109,241	$ 109,401