Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Net sales	$ 790,392	$ 757,175	$ 1,160,754	$ 1,119,129
Cost of sales	562,226	534,770	827,827	792,161
Gross profit	228,166	222,405	332,927	326,968
Selling and administrative expenses	116,173	114,271	214,002	212,813
Operating income	111,993	108,134	118,925	114,155
Interest expense, net	2,081	2,200	3,695	3,677
Income before income taxes and equity earnings	109,912	105,934	115,230	110,478
Provision for income taxes	43,416	41,018	45,312	42,055
Equity earnings in unconsolidated investments	37	27	55	171
Net income	$ 66,533	$ 64,943	$ 69,973	$ 68,594
Earnings per share:
Basic (in dollars per share)	$ 1.43	$ 1.38	$ 1.50	$ 1.45
Diluted (in dollars per share)	$ 1.39	$ 1.34	$ 1.47	$ 1.42
Weighted average shares outstanding: [Abstract]
Basic (in shares)	46,659	47,142	46,523	47,330
Diluted (in shares)	47,882	48,288	47,758	48,430
Cash dividends declared per common share	$ 0.19	$ 0.16	$ 0.35	$ 0.30