Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Net sales	$ 848,240	$ 790,392	$ 1,254,584	$ 1,160,754
Cost of sales	601,264	562,226	893,508	827,827
Gross profit	246,976	228,166	361,076	332,927
Selling and administrative expenses	124,477	116,173	229,931	214,002
Operating income	122,499	111,993	131,145	118,925
Interest expense, net	1,894	2,081	3,827	3,695
Income before income taxes and equity earnings	120,605	109,912	127,318	115,230
Provision for income taxes	46,796	43,416	49,400	45,312
Equity earnings in unconsolidated investments	54	37	133	55
Net income	$ 73,863	$ 66,533	$ 78,051	$ 69,973
Earnings per share:
Basic (in dollars per share)	$ 1.65	$ 1.43	$ 1.74	$ 1.50
Diluted (in dollars per share)	$ 1.61	$ 1.39	$ 1.69	$ 1.47
Weighted average shares outstanding: [Abstract]
Basic (in shares)	44,769	46,659	44,972	46,523
Diluted (in shares)	45,971	47,882	46,160	47,758
Cash dividends declared per common share	$ 0.22	$ 0.19	$ 0.41	$ 0.35