Consolidated Statements Of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements Of Operations [Abstract]
Net sales	$ 1,034,867	$ 867,252
Cost of sales	862,230	699,668
Gross profit	172,637	167,584
Selling, general and administrative expenses	27,012	26,947
Income from operations	145,625	140,637
Other income (expense)
Interest expense	(12,177)	(12,920)
Other income, net	1,347	1,207
Income before income taxes	134,795	128,924
Provision for income taxes	46,982	45,380
Net income	$ 87,813	$ 83,544
Earnings per share:
Basic	$ 1.32	$ 1.26
Diluted	$ 1.31	$ 1.25
Weighted average shares outstanding:
Basic	66,109,297	65,745,555
Diluted	66,558,517	66,112,858
Dividends per common share	$ 0.0738	$ 0.0635