Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Net sales	$ 597,456	$ 585,900
Cost of sales	422,825	419,827
Gross profit	174,631	166,073
Selling and administrative expenses	136,245	132,532
Operating income	38,386	33,541
Interest and other non-operating expenses, net	6,616	3,527
Income before income taxes and equity earnings	31,770	30,014
Income tax benefit	(802)	(1,279)
Equity earnings in unconsolidated investments, net	65	46
Net income	$ 32,637	$ 31,339
Earnings per share:
Basic (in dollars per share)	$ 0.83	$ 0.78
Diluted (in dollars per share)	$ 0.80	$ 0.75
Weighted average shares outstanding: [Abstract]
Basic (in shares)	39,479	40,370
Diluted (in shares)	40,696	41,862
Cash dividends declared per common share	$ 0.45	$ 0.37