CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Net sales
Unrelated parties	$ 2,004,283	$ 1,570,093	$ 3,945,947	$ 3,066,175
Related parties	75,448	62,706	149,753	122,414
Total net sales	2,079,731	1,632,799	4,095,700	3,188,589
Costs of goods sold	1,803,345	1,440,815	3,523,560	2,786,123
Gross profit	276,386	191,984	572,140	402,466
Selling, general and administrative expenses	63,631	55,957	128,772	113,117
Profit sharing	14,454	7,827	29,657	17,271
Amortization of intangible assets	10,082	11,565	20,166	23,146
Total selling, general and administrative expenses	88,167	75,349	178,595	153,534
Operating income	188,219	116,635	393,545	248,932
Interest expense, net of capitalized interest	44,812	43,448	88,158	80,963
Other income, net	(5,745)	(3,521)	(10,312)	(6,602)
Income before income taxes	149,152	76,708	315,699	174,571
Income taxes	53,326	29,911	115,643	64,385
Net income	95,826	46,797	200,056	110,186
Net loss attributable to noncontrolling interests	2,884	2,410	4,557	3,990
Net income attributable to Steel Dynamics, Inc.	$ 98,710	$ 49,207	$ 204,613	$ 114,176
Basic earnings per share attributable to Steel Dynamics, Inc. stockholders (in dollars per share)	$ 0.45	$ 0.23	$ 0.94	$ 0.53
Weighted average common shares outstanding (in shares)	218,500	216,635	218,246	216,459
Diluted earnings per share attributable to Steel Dynamics, Inc. stockholders, including the effect of assumed conversions when dilutive (in dollars per share)	$ 0.43	$ 0.22	$ 0.89	$ 0.51
Weighted average common shares and share equivalents outstanding (in shares)	236,266	234,600	236,245	234,630
Dividends declared per share (in dollars per share)	$ 0.10	$ 0.075	$ 0.20	$ 0.15