Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Net sales	$ 321,158	$ 235,537	$ 622,787	$ 566,207
Cost of sales	203,168	147,058	397,864	355,306
Selling and administrative expenses	79,447	78,364	154,000	151,472
Total operating costs and expenses	282,615	225,422	551,864	506,778
Operating income	38,543	10,115	70,923	59,429
Interest expense	4,475	3,898	8,416	8,223
Other expense (income), net	1,272	1,060	2,734	2,654
Income before income taxes	32,796	5,157	59,773	48,552
Income taxes	8,305	4,590	15,900	18,252
Net income	$ 24,491	$ 567	$ 43,873	$ 30,300
Per common share:
Basic (in dollars per share)	$ 0.48	$ 0.01	$ 0.86	$ 0.60
Diluted (in dollars per share)	$ 0.48	$ 0.01	$ 0.86	$ 0.59
Weighted average common shares outstanding:
Basic (in shares)	50,933,222	50,764,575	50,933,373	50,912,854
Diluted (in shares)	51,102,303	51,008,922	51,095,198	51,200,967