Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Net sales	$ 206,453	$ 206,692	$ 386,024	$ 377,899
Cost of sales	123,009	115,577	233,214	210,071
Gross profit	83,444	91,115	152,810	167,828
Selling, general and administrative expenses	35,705	33,513	65,872	62,472
Income from operations	47,739	57,602	86,938	105,356
Interest (income) expense, net	(1)	370	(57)	598
Income before income taxes	47,740	57,232	86,995	104,758
Provision for income taxes	12,030	14,413	19,730	24,828
Net income	$ 35,710	$ 42,819	$ 67,265	$ 79,930
Basic earnings per common share	$ 0.61	$ 0.73	$ 1.15	$ 1.36
Basic weighted average common shares outstanding	58,486,192	58,760,753	58,514,676	58,807,694
Diluted earnings per common share	$ 0.61	$ 0.73	$ 1.14	$ 1.35
Diluted weighted average common shares outstanding	58,687,540	59,051,413	58,758,201	59,125,258
Comprehensive income	$ 35,710	$ 42,819	$ 67,265	$ 79,930