Consolidated Statements Of Operations (USD $) In Thousands, except Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Consolidated Statements Of Operations [Abstract]
Net sales	$ 968,372	$ 779,677	$ 2,760,673	$ 2,376,400
Cost of sales	821,305	644,822	2,278,927	2,057,841
Gross profit	147,067	134,855	481,746	318,559
Selling, general and administrative expenses	29,736	27,509	85,409	77,247
Income from operations	117,331	107,346	396,337	241,312
Other income (expense)
Interest expense	(12,727)	(11,002)	(38,449)	(28,574)
Other income, net	1,457	622	4,296	1,536
Income before income taxes	106,061	96,966	362,184	214,274
Provision for income taxes	38,131	34,235	129,661	76,954
Net income	$ 67,930	$ 62,731	$ 232,523	$ 137,320
Earnings per share:
Basic	$ 1.02	$ 0.95	$ 3.50	$ 2.08
Diluted	$ 1.01	$ 0.95	$ 3.48	$ 2.07
Weighted average shares outstanding:
Basic	66,012,102	65,481,175	65,919,892	65,444,851
Diluted	66,381,932	65,677,989	66,307,604	65,603,089
Dividends per common share	$ 0.0738	$ 0.0635	$ 0.2008	$ 0.1785