Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Net sales	$ 330,671	$ 376,692
Cost of sales	208,248	244,643
Selling and administrative expenses	73,110	81,400
Total operating costs and expenses	281,358	326,043
Operating income	49,313	50,649
Interest expense	4,324	5,113
Other expense (income), net	1,594	1,806
Income before income taxes	43,395	43,730
Income taxes	13,662	9,738
Net income	$ 29,733	$ 33,992
Per common share:
Basic (in dollars per share)	$ 0.58	$ 0.66
Diluted (in dollars per share)	$ 0.58	$ 0.65
Weighted average common shares outstanding:
Basic (in shares)	51,061,132	51,660,804
Diluted (in shares)	51,501,857	52,189,465