Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Segment	Jun. 30, 2011	Dec. 31, 2011
Segment Information
Number of reporting segments			3
Segment Reporting Information
Net Sales, External	$ 1,803,699	$ 1,956,974	$ 3,669,369	$ 3,853,407
Net Sales, External Non-U.S.	106,104	122,757	222,474	242,293
Total net sales	1,909,803	2,079,731	3,891,843	4,095,700
Operating income (loss)	103,699	188,219	223,515	393,545
Income (loss) before income taxes	64,485	149,152	132,941	315,699
Depreciation and amortization	55,502	56,257	111,074	111,003
Capital expenditures	54,789	34,976	100,344	53,669
Assets	5,971,380	5,900,453	5,971,380	5,900,453	5,979,226
Liabilities	3,539,820	3,588,965	3,539,820	3,588,965
Steel Operations
Segment Reporting Information
Net Sales, External	1,157,908	1,221,472	2,293,820	2,367,961
Net Sales, External Non-U.S.	49,392	45,803	100,200	94,378
Net Sales, Other segments	52,923	62,191	100,682	114,137
Total net sales	1,260,223	1,329,466	2,494,702	2,576,476
Operating income (loss)	136,597	213,968	273,905	406,923
Income (loss) before income taxes	118,049	192,782	237,127	365,491
Depreciation and amortization	26,384	27,651	52,468	54,844
Capital expenditures	6,275	11,155	12,223	18,434
Assets	2,604,810	2,712,461	2,604,810	2,712,461
Liabilities	464,861	467,195	464,861	467,195
Metals Recycling and Ferrous Resources Operations
Segment Reporting Information
Net Sales, External	533,841	647,845	1,167,975	1,320,186
Net Sales, External Non-U.S.	56,668	76,834	122,134	147,658
Net Sales, Other segments	329,947	353,192	741,467	718,442
Total net sales	920,456	1,077,871	2,031,576	2,186,286
Operating income (loss)	(19,371)	3,885	(15,208)	43,375
Income (loss) before income taxes	(28,830)	(6,354)	(33,103)	22,730
Depreciation and amortization	25,591	25,706	51,665	50,620
Capital expenditures	46,857	21,632	84,763	31,883
Assets	2,607,834	2,536,751	2,607,834	2,536,751
Liabilities	574,204	563,908	574,204	563,908
Steel Fabrication Operations
Segment Reporting Information
Net Sales, External	95,767	61,939	170,659	114,018
Net Sales, Other segments		23	4	596
Total net sales	95,767	61,962	170,663	114,614
Operating income (loss)	193	(1,635)	(2,475)	(4,518)
Income (loss) before income taxes	(1,449)	(3,334)	(5,633)	(7,779)
Depreciation and amortization	2,059	1,620	3,907	3,122
Capital expenditures	1,329	419	2,497	951
Assets	255,967	229,988	255,967	229,988
Liabilities	14,807	16,715	14,807	16,715
Other
Segment Reporting Information
Net Sales, External	16,183	25,718	36,915	51,242
Net Sales, External Non-U.S.	44	120	140	257
Net Sales, Other segments	4,164	2,948	7,426	5,419
Total net sales	20,391	28,786	44,481	56,918
Operating income (loss)	(14,673)	(25,422)	(31,535)	(49,678)
Income (loss) before income taxes	(24,238)	(31,338)	(64,278)	(62,080)
Depreciation and amortization	1,519	1,331	3,136	2,519
Capital expenditures	328	1,770	861	2,401
Assets	725,717	632,242	725,717	632,242
Liabilities	2,699,661	2,740,245	2,699,661	2,740,245
Eliminations
Segment Reporting Information
Net Sales, Other segments	(387,034)	(418,354)	(849,579)	(838,594)
Total net sales	(387,034)	(418,354)	(849,579)	(838,594)
Operating income (loss)	953	(2,577)	(1,172)	(2,557)
Income (loss) before income taxes	953	(2,604)	(1,172)	(2,663)
Depreciation and amortization	(51)	(51)	(102)	(102)
Assets	(222,948)	(210,989)	(222,948)	(210,989)
Liabilities	$ (213,713)	$ (199,098)	$ (213,713)	$ (199,098)