CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets
Cash and equivalents	$ 477,861	$ 375,917
Investments in short-term commercial paper		31,520
Accounts receivable, net	703,896	599,499
Accounts receivable-related parties	49,405	42,864
Inventories	1,170,159	1,202,507
Deferred income taxes	23,564	23,449
Other current assets	24,056	20,469
Total current assets	2,448,941	2,296,225
Property, plant and equipment, net	2,232,413	2,231,198
Restricted cash	23,400	27,749
Intangible assets, net	408,832	416,635
Goodwill	736,912	738,542
Other assets	106,076	105,067
Total assets	5,956,574	5,815,416
Current liabilities
Accounts payable	401,407	344,953
Accounts payable-related parties	9,225	15,144
Income taxes payable	13,438	16,941
Accrued payroll and benefits	59,488	85,802
Accrued interest	19,290	35,306
Accrued expenses	80,257	81,900
Current maturities of long-term debt	231,582	29,631
Total current liabilities	814,687	609,677
Long-term debt
Term note	240,625	247,500
Senior notes	1,500,000	1,600,000
Convertible senior notes	287,496	287,496
Other long-term debt	41,093	37,610
Total long-term debt	2,069,214	2,172,606
Deferred income taxes	546,722	537,304
Other liabilities	19,947	19,173
Commitments and contingencies
Redeemable noncontrolling interest	99,414	98,814
Equity
Common stock voting, $.0025 par value; 900,000,000 shares authorized; 256,333,083 and 255,592,901 shares issued; and 220,333,057 and 219,522,655 shares outstanding, as of March 31, 2013 and December 31, 2012, respectively	639	637
Treasury stock, at cost; 36,000,026 and 36,070,246 shares, as of March 31, 2013 and December 31, 2012, respectively	(719,076)	(720,479)
Additional paid-in capital	1,045,973	1,037,687
Retained earnings	2,111,597	2,087,620
Total Steel Dynamics, Inc. equity	2,439,133	2,405,465
Noncontrolling interests	(32,543)	(27,623)
Total equity	2,406,590	2,377,842
Total liabilities and equity	$ 5,956,574	$ 5,815,416