Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Net sales	$ 1,139,229	$ 898,500	$ 3,097,362	$ 2,617,283
Cost of sales	810,531	640,569	2,205,555	1,854,408
Gross profit	328,698	257,931	891,807	762,875
Selling and administrative expenses	180,465	153,391	495,186	447,427
Impairment of goodwill and other assets	0	0	6,944	0
Operating income	148,233	104,540	389,677	315,448
Interest and other non-operating expenses, net	1,861	5,498	9,292	18,538
Income before income taxes and equity earnings	146,372	99,042	380,385	296,910
Income tax provision	27,360	19,593	73,068	53,569
Equity earnings in unconsolidated investments, net	86	76	248	210
Net income	$ 119,098	$ 79,525	$ 307,565	$ 243,551
Earnings per share:
Basic (in dollars per share)	$ 2.97	$ 1.99	$ 7.68	$ 6.13
Diluted (in dollars per share)	$ 2.92	$ 1.95	$ 7.53	$ 5.97
Weighted average shares outstanding: [Abstract]
Basic (in shares)	40,123	39,933	40,073	39,750
Diluted (in shares)	40,839	40,865	40,849	40,811
Cash dividends declared per common share	$ 0.58	$ 0.55	$ 1.71	$ 1.55