Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net sales	$ 1,491,118	$ 1,495,889	$ 1,436,499
Cost of sales	944,154	963,524	943,779
Selling and administrative expenses	310,516	300,601	286,269
Total operating costs and expenses	1,254,670	1,264,125	1,230,048
Operating income	236,448	231,764	206,451
Interest expense	20,629	16,841	14,571
Other expense (income), net	8,975	7,428	(3,819)
Income before income taxes	206,844	207,495	195,699
Income taxes	48,494	41,309	136,284
Net income	$ 158,350	$ 166,186	$ 59,415
Per common share:
Basic (in dollars per share)	$ 3.09	$ 3.18	$ 1.10
Diluted (in dollars per share)	$ 3.07	$ 3.15	$ 1.09
Dividends
Basic (in shares)	51,213,518	52,304,190	54,073,407
Diluted (in shares)	51,633,169	52,831,606	54,605,298