Steel Dynamics (STLD) 10-Q 10 Nov 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 31, 2014
Document and Entity Information	'	'
Entity Registrant Name	'STEEL DYNAMICS INC	'
Entity Central Index Key	'0001022671	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-14	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	240,415,834
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets	'	'
Cash and equivalents	$159,591	$395,156
Accounts receivable, net	1,013,503	664,208
Accounts receivable-related parties	45,165	56,392
Inventories	1,664,212	1,314,747
Deferred income taxes	18,402	17,964
Other current assets	29,263	25,167
Total current assets	2,930,136	2,473,634
Property, plant and equipment, net	3,420,654	2,226,134
Restricted cash	18,257	23,827
Intangible assets, net	406,318	386,159
Goodwill	727,128	731,996
Other assets	75,790	91,256
Total assets	7,578,283	5,933,006
Current liabilities	'	'
Accounts payable	621,579	404,605
Accounts payable-related parties	18,542	10,327
Income taxes payable	26,949	4,023
Accrued payroll and benefits	107,484	93,432
Accrued interest	21,277	31,363
Accrued expenses	113,851	89,884
Current maturities of long-term debt	131,858	341,544
Total current liabilities	1,041,540	975,178
Long-term debt	'	'
Senior term loan	189,062	220,000
Senior notes	2,700,000	1,500,000
Other long-term debt	40,932	46,045
Total long-term debt	2,929,994	1,766,045
Deferred income taxes	543,838	556,038
Other liabilities	24,922	23,376
Commitments and contingencies	'	'
Redeemable noncontrolling interests	126,340	116,514
Equity	'	'
Common stock voting, $.0025 par value; 900,000,000 shares authorized; 260,332,348 and 258,840,350 shares issued; and 240,365,196 and 222,867,408 shares outstanding, as of September 30, 2014 and December 31, 2013,respectively	649	645
Treasury stock, at cost; 19,967,152 and 35,972,942 shares, as of September 30, 2014 and December 31, 2013, respectively	-398,818	-718,529
Additional paid-in capital	1,075,593	1,085,694
Retained earnings	2,300,660	2,179,513
Total Steel Dynamics, Inc. equity	2,978,084	2,547,323
Noncontrolling interests	-66,435	-51,468
Total equity	2,911,649	2,495,855
Total liabilities and equity	$7,578,283	$5,933,006

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
CONSOLIDATED BALANCE SHEETS	'	'
Common stock voting, par value (in dollars per share)	$0.00	$0.00
Common stock voting, shares authorized (in shares)	900,000,000	900,000,000
Common stock voting, shares issued (in shares)	260,332,348	258,840,350
Common stock voting, shares outstanding (in shares)	240,365,196	222,867,408
Treasury stock, shares (in shares)	19,967,152	35,972,942

CONSOLIDATED_STATEMENTS_OF_INC

CONSOLIDATED STATEMENTS OF INCOME (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net sales	'	'	'	'
Unrelated parties	$2,276,747	$1,838,464	$6,030,408	$5,302,285
Related parties	62,269	73,274	208,451	206,489
Total net sales	2,339,016	1,911,738	6,238,859	5,508,774
Costs of goods sold	2,050,504	1,714,546	5,564,272	4,987,626
Gross profit	288,512	197,192	674,587	521,148
Selling, general and administrative expenses	80,240	67,553	223,745	198,171
Profit sharing	12,865	8,469	28,729	19,891
Amortization of intangible assets	6,764	7,897	20,633	24,075
Impairment charges	'	'	'	308
Total selling, general and administrative expenses	99,869	83,919	273,107	242,445
Operating income	188,643	113,273	401,480	278,703
Interest expense, net of capitalized interest	31,904	30,970	92,523	97,064
Other expense (income), net	22,072	-1,852	19,687	-4,144
Income before income taxes	134,667	84,155	289,270	185,783
Income taxes	47,010	33,065	101,574	70,168
Net income	87,657	51,090	187,696	115,615
Net loss attributable to noncontrolling interests	3,516	6,396	14,359	19,044
Net income attributable to Steel Dynamics, Inc.	$91,173	$57,486	$202,055	$134,659
Basic earnings per share attributable to Steel Dynamics, Inc. stockholders (in dollars per share)	$0.38	$0.26	$0.88	$0.61
Weighted average common shares outstanding (in shares)	240,087	220,926	229,772	220,464
Diluted earnings per share attributable to Steel Dynamics, Inc. stockholders, including the effect of assumed conversions when dilutive (in dollars per share)	$0.38	$0.25	$0.85	$0.59
Weighted average common shares and share equivalents outstanding (in shares)	242,244	239,001	241,895	238,497
Dividends declared per share (in dollars per share)	$0.12	$0.11	$0.35	$0.33

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Operating activities:	'	'	'	'
Net income	$87,657	$51,090	$187,696	$115,615
Adjustments to reconcile net income to net cash provided by operating activities:	'	'	'	'
Depreciation and amortization	65,957	58,202	181,966	172,089
Equity-based compensation	5,104	2,515	15,572	9,612
Impairment charges	'	'	'	308
Deferred income taxes	-3,417	9,861	-7,788	31,608
(Gain) loss on disposal of property, plant and equipment	-662	1,739	5,435	944
Changes in certain assets and liabilities:	'	'	'	'
Accounts receivable	30,955	254	-157,691	-130,510
Inventories	27,212	-23,648	21,088	10,360
Other assets	-4,928	-1,727	2,776	8,414
Accounts payable	9,690	59,801	28,116	52,419
Income taxes receivable/payable	8,062	16,354	22,491	-9,972
Accrued expenses and liabilities	23,594	8,825	-1,670	-15,196
Net cash provided by operating activities	249,224	183,266	297,991	245,691
Investing activities:	'	'	'	'
Purchases of property, plant and equipment	-24,531	-52,162	-82,906	-146,744
Acquisition of business, net of cash acquired	-1,647,463	'	-1,647,463	'
Proceeds from maturities of short-term commercial paper	'	'	'	31,520
Other investing activities	2,959	844	34,157	4,121
Net cash used in investing activities	-1,669,035	-51,318	-1,696,212	-111,103
Financing activities:	'	'	'	'
Issuance of current and long-term debt	1,394,497	9,526	1,501,895	418,819
Repayment of current and long-term debt	-138,533	-4,097	-271,191	-512,100
Debt issuance costs	-18,020	'	-18,020	-6,192
Exercise of stock options proceeds, including related tax impact	11,576	7,925	22,997	18,516
Contributions from noncontrolling investors, net	-52	5,275	4,712	10,972
Dividends paid	-27,556	-24,274	-77,737	-70,464
Net cash provided by (used in) financing activities	1,221,912	-5,645	1,162,656	-140,449
Increase (decrease) in cash and equivalents	-197,899	126,303	-235,565	-5,861
Cash and equivalents at beginning of period	357,490	243,753	395,156	375,917
Cash and equivalents at end of period	159,591	370,056	159,591	370,056
Supplemental disclosure information:	'	'	'	'
Cash paid for interest	40,022	40,075	100,523	107,390
Cash paid for federal and state income taxes, net	$41,267	$3,022	$86,418	$41,547

Description_of_the_Business_an

Description of the Business and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2014
Description of the Business and Significant Accounting Policies	'
Description of the Business and Significant Accounting Policies	'
	Note 1.  Description of the Business and Significant Accounting Policies
	Description of the Business
	Steel Dynamics, Inc. (SDI), together with its subsidiaries (the company), is a domestic manufacturer of steel products and metals recycler. The company has three reporting segments: steel operations, metals recycling and ferrous resources operations, and steel fabrication operations.
	Steel Operations.  Steel operations include the company’s —Butler Flat Roll Division, Columbus Flat Roll Division (acquired September 16, 2014), The Techs galvanizing lines, Structural and Rail Division, Engineered Bar Products Division, Roanoke Bar Division and Steel of West Virginia. These operations consist of mini-mills, producing steel from steel scrap, using electric arc furnaces, continuous casting, automated rolling mills, and downstream finishing facilities. Steel operations accounted for 62% and 61% of the company’s external net sales during the three-month periods ended September 30, 2014 and 2013, respectively, and 61% and 60% of the company’s external net sales during the nine-month periods ended September 30, 2014 and 2013, respectively.
	Metals Recycling and Ferrous Resources Operations. Metals recycling and ferrous resources operations primarily include OmniSource Corporation, the company’s metals recycling, steel scrap procurement, and processing locations, and our two ironmaking initiatives: Iron Dynamics, a liquid pig iron production facility; and our Minnesota iron operations, an iron nugget production facility and operations to supply the nugget facility with its primary raw material, iron concentrate. Metals recycling and ferrous resources operations accounted for 29% and 32% of the company’s external net sales during the three-month periods ended September 30, 2014 and 2013, respectively, and 30% and 33% of the company’s external net sales during the nine-month periods ended September 30, 2014 and 2013, respectively.
	Steel Fabrication Operations.  Steel fabrication operations include the company’s six New Millennium Building Systems joist and deck plants located throughout the United States and Northern Mexico. Revenues from these plants are generated from the fabrication of trusses, girders, steel joists and steel decking used within the non-residential construction industry. Steel fabrication operations accounted for approximately 8% and 6% of the company’s external net sales during the three-month periods ended September 30, 2014 and 2013, respectively, and 7% and 6% of the company’s external net sales during the nine-month periods ended September 30, 2014 and 2013, respectively.
	Significant Accounting Policies
	Principles of Consolidation.  The consolidated financial statements include the accounts of SDI, together with its wholly and majority-owned or controlled subsidiaries, after elimination of significant intercompany accounts and transactions. Noncontrolling interests represent the noncontrolling owner’s proportionate share in the equity, income, or losses of the company’s majority-owned or controlled consolidated subsidiaries.
	Use of Estimates.  These financial statements are prepared in conformity with accounting principles generally accepted in the United States and, accordingly, include amounts that require management to make estimates and assumptions that affect the amounts reported in the financial statements and in the notes thereto. Significant items subject to such estimates and assumptions include the carrying value of property, plant and equipment, intangible assets and goodwill; valuation allowances for trade receivables, inventories and deferred income tax assets; unrecognized tax benefits; potential environmental liabilities; and litigation claims and settlements. Actual results may differ from these estimates and assumptions.
	In the opinion of management, these financial statements reflect all normal recurring adjustments necessary for a fair presentation of the interim period results. These financial statements and notes should be read in conjunction with the audited financial statements and notes thereto included in the company’s Annual Report on Form 10-K for the year ended December 31, 2013.
	Goodwill.  The company’s goodwill is allocated to the following reporting units at September 30, 2014, and December 31, 2013, (in thousands):
		September 30,		December 31,
		2014		2013
	OmniSource — Metals Recycling/Ferrous Resources Segment	$	553,379	$	558,247
	The Techs — Steel Segment	142,783		142,783
	Roanoke Bar Division — Steel Segment	29,041		29,041
	New Millennium Building Systems — Fabrication Segment	1,925		1,925
		$	727,128	$	731,996
	OmniSource goodwill decreased $4.9 million from December 31, 2013 to September 30, 2014, in recognition of the 2014 tax benefit related to the amortization of the component of OmniSource tax-deductible goodwill in excess of book goodwill.
	Additional goodwill, if any, allocated to Columbus may be determined after the accounting for the Columbus acquisition is completed (see Note 2).
	Recently Issued Accounting Standards.
	In May 2014, the FASB issued guidance codified in ASC 606, Revenue Recognition — Revenue from Contracts with Customers, which amends the guidance in former ASC 605, Revenue Recognition. The company is currently evaluating the impact of the provisions of ASC 606.
	In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements — Going Concern (Subtopic 205-40: Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern), effective for annual and interim periods ending after December 15, 2016. ASU 2014-15 requires management to evaluate whether there are conditions or events, considered in aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued. There are required disclosures if substantial doubt is identified including documentation of principal conditions or events that raised substantial doubt about the entity’s ability to continue as a going concern (before consideration of management’s plans), management’s evaluation of the significance of those conditions or events in relation to the entity’s ability to meet its obligations, and management’s plans that alleviated substantial doubt about the entity’s ability to continue as a going concern. This ASU is not expected to have any impact on our overall results of operations, financial position or cash flows.

Acquisition

Acquisition	9 Months Ended
	Sep. 30, 2014
Acquisition	'
Acquisition	'
	Note 2.  Acquisition
	On September 16, 2014, the company completed its acquisition of 100% of Severstal Columbus, LLC (Columbus), on a debt-free basis, for a purchase price of $1.625 billion, with additional working capital adjustments of $35.3 million. The Columbus acquisition was funded through the issuance of $1.2 billion in Senior Notes (See Note 5), borrowings under the company’s senior secured credit facility and available cash. The company purchased Columbus to significantly expand and diversify its steel operating base with the addition of 3.4 million tons of hot roll steel production capacity diversified with respect to width, gauge, and strength when compared to the capabilities of our Butler Flat Roll Division. Located in northeast Mississippi, Columbus is one of the newest and most technologically advanced sheet steel mini-mills in North America, with access to the high-growth oil country tubular goods (OCTG) and automotive markets. Additionally, is advantageously located to serve the growing markets in the southern U.S. and Mexico, providing the company with geographic diversification and growth opportunities.  Columbus’ operating results have been reflected in the company’s financial statements since September 16, 2014, the effective date of the acquisition, in the steel operations reporting segment. Columbus reported revenues of $126.5 million and $13.5 million pretax income during the September 16 to September 30, 2014 period, before giving effect to $14.5 million of purchase accounting related cost of goods sold expenses associated with the estimated step-up in inventory and fixed assets. In conjunction with the acquisition, the company recognized $25.0 million of acquisition and related costs that are included in other expenses in the consolidated income statements for the three- and nine-month periods ended September 30, 2014.
	The aggregate purchase price was preliminarily allocated to the opening balance sheet of Columbus as of the September 16, 2014 acquisition date.  The following initial allocation of the purchase price (in thousands) is preliminary. The accounting for the acquisition has not yet been completed because we have not finalized the valuations of the acquired assets, assumed liabilities and identifiable intangible assets, including goodwill, if any.
	Current assets, net of cash acquired	$	551,255
	Property, plant & equipment	1,298,065
	Intangible assets	40,000
	Other assets	3,682
	Total assets acquired	1,893,002
	Liabilities assumed	232,735
	Net assets acquired	$	1,660,267
	We provisionally assigned $40.0 million of intangible assets to customer relationships with an assigned ten-year life. The company plans to utilize an accelerated amortization methodology to follow the pattern in which the economic benefits of the intangible assets are anticipated to be consumed. However, the expected life and specific amortization method is subject to finalization of the company’s valuation process.
	Unaudited Pro Forma Results
	Columbus’ operating results have been reflected in the company’s financial statements since the effective date of the acquisition, September 16, 2014.  The following unaudited pro forma information is presented below as if the Columbus acquisition was completed as of January 1, 2013, (in thousands, except per share amounts):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
	Net Sales	$	2,853,272	$	2,408,316	$	7,838,681	$	6,855,029
	Net Income attributable to Steel Dynamics, Inc.	$	137,516	$	57,948	$	299,681	$	84,118
	The information presented is for information purposes only and is not necessarily indicative of the actual results that would have occurred had the acquisition been consummated at the beginning of the respective period, nor are they necessarily indicative of future operating results of the combined companies under the ownership and management of the company.  The 2014 and 2013 pro forma results reflect Columbus operations for the three- and nine-month periods ended September 30, 2014 and 2013.   As the unaudited pro forma information is presented as if the merger had occurred on January 1, 2013, the gross margin reduction related to the estimated step-up in inventory of $17.7 million and acquisition and related costs of $25.0 million is reflected in the first quarter of 2013. Therefore, the effect of these items is included in the nine-month period ended September 30, 2013 unaudited pro forma results presented above, but not in the nine-month period ended September 30, 2014, or either of the three-month periods.

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2014
Earnings Per Share	'
Earnings Per Share	'
	Note 3.  Earnings Per Share
	Basic earnings per share is based on the weighted average shares of common stock outstanding during the period. Diluted earnings per share assumes the weighted average dilutive effect of common share equivalents outstanding during the period applied to the company’s basic earnings per share. Common share equivalents represent potentially dilutive stock options, restricted stock units, deferred stock units, and dilutive shares related to the company’s 5.125% Convertible Senior Notes, which matured on June 15, 2014 and were dilutive through then; and are excluded from the computation in periods in which they have an anti-dilutive effect. No options to purchase shares were anti-dilutive at September 30, 2014, while options to purchase 2.4 million shares were anti-dilutive at September 30, 2013.
	The following table presents a reconciliation of the numerators and the denominators of the company’s basic and diluted earnings per share computations for net income attributable to Steel Dynamics, Inc. (in thousands, except per share data):
		Three Months Ended September 30,
		2014					2013
		Net Income		Shares	Per Share		Net Income		Shares	Per Share
		(Numerator)		(Denominator)	Amount		(Numerator)		(Denominator)	Amount
	Basic earnings per share	$	91,173	240,087	$	0.38	$	57,486	220,926	$	0.26
	Dilutive common share equivalents	—		2,157			—		1,366
	5.125% Convertible Senior Notes, net of tax	—		—			2,358		16,709
	Diluted earnings per share	$	91,173	242,244	$	0.38	$	59,844	239,001	$	0.25
		Nine Months Ended September 30,
		2014					2013
		Net Income		Shares	Per Share		Net Income		Shares	Per Share
		(Numerator)		(Denominator)	Amount		(Numerator)		(Denominator)	Amount
	Basic earnings per share	$	202,055	229,772	$	0.88	$	134,659	220,464	$	0.61
	Dilutive common share equivalents	—		1,852			—		1,363
	5.125% Convertible Senior Notes, net of tax	4,327		10,271			7,074		16,670
	Diluted earnings per share	$	206,382	241,895	$	0.85	$	141,733	238,497	$	0.59

Inventories

Inventories	9 Months Ended
	Sep. 30, 2014
Inventories	'
Inventories	'
	Note 4.  Inventories
	Inventories are stated at lower of cost or market.  Cost is determined using a weighted average cost method for scrap, and on a first-in, first-out basis for all other inventory.  Inventory consisted of the following (in thousands):
		September 30,		December 31,
		2014		2013
	Raw materials	$	766,209	$	660,384
	Supplies	365,504		293,533
	Work in progress	148,712		84,710
	Finished goods	383,787		276,120
	Total inventories	$	1,664,212	$	1,314,747

Debt

Debt	9 Months Ended
	Sep. 30, 2014
Debt	'
Debt	'
	Note 5.  Debt
	On September 9, 2014, the company issued $700.0 million of 5.125% Senior Notes due 2021 (2021 Senior Notes) and $500.0 million of 5.500% Senior Notes due 2024 (2024 Senior Notes), combined the Senior Notes. The proceeds from the issuance of the Senior Notes, along with cash on hand and borrowings under the company’s senior secured credit facility were used to fund the September 16, 2014 acquisition of Columbus.  Interest on the Senior Notes is due semiannually on October 1 and April 1, with the first payment due on April 1, 2015. The Senior Notes are unsecured and rank pari passu with all existing and future senior unsubordinated unsecured indebtedness and senior in right of payment to all subordinated indebtedness.
		·	The 2021 Senior Notes are redeemable at any time on and after October 1, 2017. The redemption price (expressed as a percentage of principal amount) is 102.563% during the period October 1, 2017 to September 30, 2018; 101.281% during the period October 1, 2018 to September 30, 2019; and 100% on and after October 1, 2019; each plus accrued interest to, but excluding, the redemption date. In addition, at any time prior to October 1, 2017, the company may redeem up to 35% of the principal amount of the 2021 Senior Notes at the redemption price of 105.125% of its principal amount plus accrued interest to, but excluding, the redemption date, with the net cash proceeds from one or more sales of the company’s common stock. At any time prior to October 1, 2017, the company may redeem some or all of the 2021 Senior Notes by paying a “make-whole” premium plus accrued interest to, but excluding, the redemption date.
		·	The 2024 Senior Notes are redeemable at any time on and after October 1, 2019. The redemption price (expressed as a percentage of principal amount) is 102.750% during the period October 1, 2019 to September 30, 2020; 101.833% during the period October 1, 2020 to September 30, 2021; 100.917% during the period October 1, 2021 to September 30, 2022; and 100% on and after October 1, 2022; each plus accrued interest to, but excluding, the redemption date. In addition, at any time prior to October 1, 2017, the company may redeem up to 35% of the principal amount of the 2024 Senior Notes at the redemption price of 105.500 of its principal amount plus accrued interest to, but excluding, the redemption date, with the net cash proceeds from one or more sales of the company’s common stock. At any time prior to October 1, 2019, the company may redeem some or all of the 2024 Senior Notes by paying a “make-whole” premium plus accrued interest to, but excluding, the redemption date.
	Holders of $271.8 million principal amount of the company’s 5.125% Convertible Senior Notes due June 15, 2014 (the “Notes”) exercised their option to convert the Notes into shares of common stock by the close of business on June 12, 2014, the conversion election deadline. The conversion rate provided under the terms of the Notes was 58.4731 shares of common stock per $1,000 principal amount of Notes, equivalent to a conversion price of approximately $17.10 per share of common stock, resulting in the company issuing a total of 15,893,457 shares of common stock from treasury shares upon conversion of the Notes. The remaining $15.7 million of the outstanding Notes was paid in cash on June 16, 2014.

Changes_in_Equity

Changes in Equity	9 Months Ended
	Sep. 30, 2014
Changes in Equity	'
Changes in Equity	'
	Note 6.  Changes in Equity
	The following table provides a reconciliation of the beginning and ending carrying amounts of total equity, equity attributable to stockholders of Steel Dynamics, Inc. and equity and redeemable amounts attributable to the noncontrolling interests (in thousands):
		Stockholders of Steel Dynamics, Inc.
		Common		Additional			Retained			Treasury			Noncontrolling			Total			Redeemable
				Paid-In															Noncontrolling
		Stock		Capital			Earnings			Stock			Interests			Equity			Interests
	Balances at January 1, 2014	$	645	$	1,085,694		$	2,179,513		$	(718,529	)	$	(51,468	)	$	2,495,855		$	116,514
	Proceeds from the exercise of stock options, including related tax effect	4		23,075			—			—			—			23,079			—
	Dividends declared	—		—			(80,863		)	—			—			(80,863		)	—
	Conversion of 5.125% Convertible Senior Notes	—		(45,650		)	—			317,451			—			271,801			—
	Equity-based compensation and issuance of restricted stock	—		12,474			(45		)	2,260			—			14,689			—
	Contributions from noncontrolling investors	—		—			—			—			97			97			9,826
	Distributions to noncontrolling investors	—		—			—			—			(705		)	(705		)	—
	Net income (loss)	—		—			202,055			—			(14,359		)	187,696			—
	Balances at September 30, 2014	$	649	$	1,075,593		$	2,300,660		$	(398,818	)	$	(66,435	)	$	2,911,649		$	126,340

Derivative_Financial_Instrumen

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2014
Derivative Financial Instruments	'
Derivative Financial Instruments	'
	Note 7.  Derivative Financial Instruments
	The company is exposed to certain risks relating to its ongoing business operations. The company utilizes derivative instruments to mitigate interest rate risk, foreign currency exchange rate risk, and commodity margin risk. Interest rate swaps may be entered into to manage interest rate risk associated with the company’s fixed and floating-rate borrowings. Forward exchange contracts on various foreign currencies may be entered into to manage foreign currency exchange rate risk as necessary. No interest rate swaps or forward exchange contracts on foreign currency existed for the periods presented. The company routinely enters into forward exchange traded futures and option contracts to manage the price risk associated with nonferrous metals inventory as well as purchases and sales of nonferrous metals (specifically aluminum, copper, nickel and silver).  The company offsets fair value amounts recognized for derivative instruments executed with the same counterparty under master netting agreements. The company designates certain of its nonferrous metals, forward exchange futures contracts as fair value hedges of inventory and firm sales commitments.
	Commodity Futures Contracts.  If the company is “long” on a futures contract, it means the company has more futures contracts purchased than futures contracts sold for the underlying commodity.  If the company is “short” on a futures contract, it means the company has more futures contracts sold than futures contracts purchased for the underlying commodity. The following summarizes the company’s futures contract commitments as of September 30, 2014 (MT represents metric tons and Lbs represents pounds):
	Commodity Futures	Long/Short	Total
	Aluminum	Long	3,300		MT
	Aluminum	Short	3,975		MT
	Copper	Long	6,226		MT
	Copper	Short	18,296		MT
	Silver	Short	343		Lbs
	The following summarizes the location and amounts of the fair values reported on the company’s balance sheets as of September 30, 2014, and December 31, 2013, and gains and losses related to derivatives included in the company’s statement of income for the three- and nine-month periods ended September 30, 2014 and 2013 (in thousands):
		Asset Derivatives							Liability Derivatives
			Fair Value						Fair Value
		Balance sheet location	September 30,			December 31, 2013			September 30,			December 31, 2013
			2014						2014
	Derivative instruments designated as fair value hedges -
	Commodity futures	Other current assets	$	3,373		$	658		$	528		$	1,886
	Derivative instruments not designated as hedges -
	Commodity futures	Other current assets	$	1,757		$	352		$	697		2,601
	Total derivative instruments		$	5,130		$	1,010		$	1,225		$	4,487
	The fair value of the above derivative instruments along with required margin deposit amounts with the same counterparty under master netting arrangements, which totaled $7.0 million at September 30, 2014 and $3.6 million at December 31, 2013, are reflected in other current assets in the consolidated balance sheet.
		Location of gain (loss)	Amount of gain (loss) recognized						Hedged items		Location of gain (loss)		Amount of gain (loss) recognized
			in income on derivatives for the										in income on related hedged items
			three months ended										for the three months ended
		recognized in income	September 30,			September 30,			in fair value hedge		recognized in income		September 30,			September 30,
		on derivatives	2014			2013			relationships		on related hedged item		2014			2013
	Derivatives in fair value hedging relationships -
	Commodity futures	Costs of goods sold	$	4,371		$	381		Firm commitments		Costs of goods sold		$	784		$	(1,736	)
									Inventory		Costs of goods sold		(4,163		)	364
													$	(3,379	)	$	(1,372	)
	Derivatives not designated as hedging instruments -
	Commodity futures	Costs of goods sold	$	2,672		$	(2,836	)
		Location of gain (loss)	Amount of gain recognized in						Hedged items		Location of gain (loss)		Amount of gain (loss) recognized in
			income on derivatives for the nine										income on related hedged items for
			months ended										the nine months ended
		recognized in income on	September 30,			September 30,			in fair value hedge		recognized in income on		September 30,			September 30,
		derivatives	2014			2013			relationships		related hedged item		2014			2013
	Derivatives in fair value hedging relationships -
	Commodity futures	Costs of goods sold	$	3,356		$	7,773		Firm commitments		Costs of goods sold		$	1,115		$	877
									Inventory		Costs of goods sold		(3,805		)	(8,458		)
													$	(2,690	)	$	(7,581	)
	Derivatives not designated as hedging instruments -
	Commodity futures	Costs of goods sold	$	8,598		$	3,793
	Derivatives accounted for as fair value hedges had ineffectiveness resulting in losses of $229,000 and $312,000 during the three-month periods ended September 30, 2014 and 2013, respectively; and a gain of $227,000 and loss of $199,000 during the nine-month periods ended September 30, 2014 and 2013, respectively. A gain excluded from hedge effectiveness testing of $1.2 million reduced costs of goods sold and a loss of $678,000 increased costs of goods sold during the three-month periods ended September 30, 2014 and 2013, respectively. Gain excluded from hedge effectiveness testing of $439,000 and $392,000 reduced cost of goods sold during the nine-month periods ended September 30, 2014 and 2013, respectively.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2014
Fair Value Measurements	'
Fair Value Measurements	'
	Note 8.  Fair Value Measurements
	FASB accounting standards provide a comprehensive framework for measuring fair value and sets forth a definition of fair value and establishes a hierarchy prioritizing the inputs to valuation techniques, giving the highest priority to quoted prices in active markets for identical assets and liabilities and the lowest priority to unobservable value inputs.  Levels within the hierarchy are defined as follows:
		·		Level 1—Unadjusted quoted prices for identical assets and liabilities in active markets;
		·		Level 2—Quoted prices for similar assets and liabilities in active markets (other than those included in Level 1) which are observable for the asset or liability, either directly or indirectly; and
		·		Level 3—Valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable.
	The following table sets forth financial assets and liabilities measured at fair value in the consolidated balance sheets and the respective levels to which the fair value measurements are classified within the fair value hierarchy as of  September 30, 2014, and December 31, 2013 (in thousands):
			Total		Quoted Prices in		Significant		Significant
					Active Markets		Other		Unobservable
					for Identical		Observable		Inputs
					Assets		Inputs		(Level 3)
					(Level 1)		(Level 2)
	September 30, 2014
	Commodity futures — financial assets		$	5,130	$	—	$	5,130	$	—
	Commodity futures — financial liabilities		1,225		—		1,225		—
	December 31, 2013
	Commodity futures — financial assets		$	1,010	$	—	$	1,010	$	—
	Commodity futures — financial liabilities		4,487		—		4,487		—
	The carrying amounts of financial instruments including cash and equivalents approximate fair value. The fair values of commodity futures contracts are estimated by the use of quoted market prices, estimates obtained from brokers, and other appropriate valuation techniques based on references available. The fair value of long-term debt, including current maturities, as determined by quoted market prices (Level 2), was approximately $3.1 billion and $2.3 billion (with a corresponding carrying amount in the consolidated balance sheets of $3.1 billion and $2.1 billion) at September 30, 2014 and December 31, 2013, respectively. Assets and liabilities acquired in business combinations are recorded at their fair value as of the date of acquisition. Refer to Note 2 for the provisional fair values of assets acquired and liabilities assumed in connection with the company’s Columbus acquisition.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies	'
Commitments and Contingencies	'
	Note 9.  Commitments and Contingencies
	The company is involved in various routine litigation matters, including administrative proceedings, regulatory proceedings, governmental investigations, environmental matters, and commercial and construction contract disputes, none of which are expected to have a material impact on our financial condition, results of operations, or liquidity.
	The company is involved, along with other steel manufacturing companies, in a class action antitrust complaint filed in federal court in Chicago, Illinois in September 2008, which alleges a conspiracy to fix, raise, maintain and stabilize the price at which steel products were sold in the United States during a period between 2005 and 2007, by artificially restricting the supply of such steel products. All but one of the complaints were brought on behalf of a purported class consisting of all direct purchasers of steel products.  The other complaint was brought on behalf of a purported class consisting of all indirect purchasers of steel products within the same time period.  A ninth complaint, in December 2010, was brought on behalf of indirect purchasers of steel products in Tennessee and has been consolidated with the original complaints.  All complaints seek treble damages and costs, including reasonable attorney fees, pre- and post-judgment interest and injunctive relief.  Following a period of discovery relating to class certification matters, plaintiffs’ motion for class action certification filed in 2012, and briefing by both sides, the court, on March 5 — 7 and April 11, 2014, held a class certification hearing. At the conclusion of the hearing, the court took the class certification issue under advisement. It’s unclear when the court will issue its ruling.
	Due to the uncertain nature of litigation, the company cannot presently determine the ultimate outcome of this litigation.  However, we have determined, based on the information available at this time, that there is not presently a “reasonable possibility” (as that term is defined in ASC 450-20-20), that the outcome of these legal proceedings would have a material impact on our financial condition, results of operations, or liquidity.  Although not presently necessary or appropriate to make a dollar estimate of exposure to loss, if any, in connection with the above matter, we may in the future determine that a loss accrual is necessary. Although we may make loss accruals, if and as warranted, any amounts that we may accrue from time to time could vary significantly from the amounts we actually pay, due to inherent uncertainties and the inherent shortcomings of the estimation process, the uncertainties involved in litigation and other factors. Additionally, an adverse result could have a material effect on our financial condition, results of operations and liquidity.

Segment_Information

Segment Information	9 Months Ended
	Sep. 30, 2014
Segment Information	'
Segment Information	'
	Note 10.  Segment Information
	The company has three reportable segments: steel operations, metals recycling and ferrous resources operations, and steel fabrication operations.  Columbus is reported in the steel operations reporting segment from its September 16, 2014 acquisition date. The segment operations are described in Note 1 to the financial statements.  Revenues included in the category “Other” are from subsidiary operations that are below the quantitative thresholds required for reportable segments and primarily consist of further processing, slitting, and sale of certain steel products and the resale of certain secondary and excess steel products.  In addition, “Other” also includes certain unallocated corporate accounts, such as the company’s senior secured credit facility, senior notes, 5.125% Convertible Senior Notes (which matured on June 15, 2014), certain other investments, and certain profit sharing expenses.
	The company’s operations are primarily organized and managed by operating segment.  Operating segment performance and resource allocations are primarily based on operating results before income taxes.  The accounting policies of the reportable segments are consistent with those described in Note 1 to the financial statements. Intra-segment and intra-company sales and any related profits are eliminated in consolidation. Refer to the company’s Annual Report on Form 10-K for the year ended December 31, 2013, for more information related to the company’s segment reporting.  The company’s segment results for the three- and nine-month periods ended September 30, 2014 and 2013 are as follows (in thousands):
	For the three months ended					Metals Recycling /			Steel Fabrication
	September 30, 2014		Steel Operations			Ferrous Resources			Operations		Other			Eliminations			Consolidated
	Net Sales
	External		$	1,400,370		$	609,098		$	189,993	$	25,084		$	—		$	2,224,545
	External Non-U.S.		50,842			63,299			—		330			—			114,471
	Other segments		75,320			326,090			43		8,340			(409,793		)	—
			1,526,532			998,487			190,036		33,754			(409,793		)	2,339,016
	Operating income (loss)		200,116			(5,330		)	19,474		(26,733		)(1)	1,116		-2	188,643
	Income (loss) before income taxes		184,589			(11,724		)	17,877		(57,191		)(7)	1,116			134,667
	Depreciation and amortization		32,998			28,775			2,974		1,262			(52		)	65,957
	Capital expenditures		12,195			11,599			477		260			—			24,531
	As of September 30, 2014
	Assets		4,553,924			2,531,821			315,381		427,654		-3	(250,497		)(4)	7,578,283
	Liabilities		821,796			651,128			34,386		3,273,198		-5	(240,214		)(6)	4,540,294
	Footnotes related to the three months ended September 30, 2014 segment results (in millions):
	-1	Corporate SG&A		$	(12.4	)
		Company-wide equity-based compensation		(5.1		)
		Profit sharing		(11.6		)
		Other, net		2.4
				$	(26.7	)
	-2	Gross profit increase from intra-company sales		$	1.1
	-3	Cash and equivalents		$	80.3
		Accounts receivable		12.8
		Inventories		15.2
		Deferred income taxes		18.3
		Property, plant and equipment, net		70.2
		Debt issuance costs		39.6
		Intra-company debt		160.2
		Other		31.1
				$	427.7
	-4	Elimination of intra-company receivables		$	(80.7	)
		Elimination of intra-company debt		(160.2		)
		Other		(9.6		)
				$	(250.5	)
	-5	Accounts payable		$	76.9
		Income taxes payable		26.9
		Accrued interest		21.1
		Accrued profit sharing		25.2
		Debt		2,990.20
		Deferred income taxes		97.4
		Other		35.5
				$	3,273.20
	-6	Elimination of intra-company payables		$	(81.2	)
		Elimination of intra-company debt		(160.2		)
		Other		1.2
				$	(240.2	)
	-7	Includes $25.0 million of acquisition and bridge financing costs associated with the acquisition of Columbus.
	For the three months ended					Metals Recycling /			Steel Fabrication
	September 30, 2013		Steel Operations			Ferrous Resources			Operations		Other			Eliminations			Consolidated
	Net Sales
	External		$	1,102,048		$	557,765		$	119,134	$	24,593		$	—		$	1,803,540
	External Non-U.S.		60,381			47,616			—		201			—			108,198
	Other segments		54,537			313,113			134		7,918			(375,702		)	—
			1,216,966			918,494			119,268		32,712			(375,702		)	1,911,738
	Operating income (loss)		146,564			(17,135		)	3,265		(17,274		)(1)	(2,147		)(2)	113,273
	Income (loss) before income taxes		133,041			(24,567		)	1,751		(23,922		)	(2,148		)	84,155
	Depreciation and amortization		26,815			27,713			2,219		1,506			(51		)	58,202
	Capital expenditures		33,985			17,385			297		495			—			52,162
	As of September 30, 2013
	Assets		2,581,798			2,530,979			272,786		699,244		-3	(210,502		)(4)	5,874,305
Liabilities		533,966			593,674			22,908		2,366,273		-5	(200,304		)(6)	3,316,517
Footnotes related to the three months ended September 30, 2013 segment results (in millions):
-1	Corporate SG&A		$	(9.2	)
	Company-wide equity-based compensation		(2.1		)
	Profit sharing		(7.4		)
	Other, net		1.4
	Total		$	(17.3	)
-2	Gross profit reduction from intra-company sales		$	(2.1	)
-3	Cash and equivalents		$	325.8
	Accounts receivable		13.4
	Inventories		14
	Deferred income taxes		25.2
	Property, plant and equipment, net		72.9
	Debt issuance costs, net		27.7
	Intra-company debt		153.6
	Other		66.6
	Total		$	699.2
-4	Elimination of intra-company receivables		$	(46.9	)
	Elimination of intra-company debt		(153.6		)
	Other		(10.0		)
	Total		$	(210.5	)
-5	Accounts payable		$	43.1
	Income taxes payable		7.7
	Accrued interest		22.9
	Accrued profit sharing		19.5
	Debt		2,041.80
	Deferred income taxes		204.6
	Other		26.7
	Total		$	2,366.30
-6	Elimination of intra-company payables		$	(47.3	)
	Elimination of intra-company debt		(153.6		)
	Other		0.6
	Total		$	(200.3	)
For the nine months ended					Metals Recycling /			Steel Fabrication
September 30, 2014		Steel Operations			Ferrous Resources			Operations		Other			Eliminations			Consolidated
Net Sales
External		$	3,675,696		$	1,714,440		$	440,706	$	69,886		$	—		$	5,900,728
External Non-U.S.		158,218			178,947			—		966			—			338,131
Other segments		188,854			973,635			43		22,322			(1,184,854		)	—
		4,022,768			2,867,022			440,749		93,174			(1,184,854		)	6,238,859
Operating income (loss)		461,708			(26,902		)	30,190		(67,437		)(1)	3,921		-2	401,480
Income (loss) before income taxes		419,181			(47,054		)	25,628		(112,406		)(3)	3,921			289,270
Depreciation and amortization		89,244			81,266			7,597		4,013			(154		)	181,966
Capital expenditures		47,133			33,762			1,324		687			—			82,906
Footnotes related to the nine months ended September 30, 2014 segment results (in millions):
-1	Corporate SG&A		$	(31.7	)
	Company-wide equity-based compensation		(14.4		)
	Profit sharing		(25.2		)
	Other, net		3.9
	Total		$	(67.4	)
-2	Gross profit increase from intra-company sales		$	3.9
-3	Includes $25.0 million of acquisition and bridge financing costs associated with the acquisition of Columbus.
For the nine months ended					Metals Recycling /			Steel Fabrication
September 30, 2013		Steel Operations			Ferrous Resources			Operations		Other			Eliminations			Consolidated
Net Sales
External		$	3,152,111		$	1,653,975		$	316,526	$	64,792		$	—		$	5,187,404
External Non-U.S.		162,646			158,026			—		698			—			321,370
Other segments		168,482			865,143			1,276		20,198			(1,055,099		)	—
		3,483,239			2,677,144			317,802		85,688			(1,055,099		)	5,508,774
Operating income (loss)		351,410			(34,210		)	7,125		(48,147		)(1)	2,525		-2	278,703
Income (loss) before income taxes		309,780			(56,860		)	2,475		(72,136		)	2,524			185,783
Depreciation and amortization		79,698			81,553			6,455		4,536			(153		)	172,089
Capital expenditures		93,244			49,999			2,000		1,501			—			146,744
Footnotes related to the nine months ended September 30, 2013 segment results (in millions):
-1	Corporate SG&A		$	(26.3	)
	Company-wide equity-based compensation		(7.3		)
	Profit sharing		(16.5		)
	Other, net		2
	Total		$	(48.1	)
-2	Gross profit increase from intra-company sales		$	2.5

Condensed_Consolidating_Inform

Condensed Consolidating Information	9 Months Ended
	Sep. 30, 2014
Condensed Consolidating Information	'
Condensed Consolidating Information	'
	Note 11.  Condensed Consolidating Information
	Certain 100%-owned subsidiaries of SDI have fully and unconditionally guaranteed all of the indebtedness relating to the issuance of the company’s senior notes due 2019, 2020, 2021, 2022, 2023, and 2024. Following are the company’s condensed consolidating financial statements, including the guarantors, which present the financial position, results of operations and cash flows of (i) SDI (in each case, reflecting investments in its consolidated subsidiaries under the equity method of accounting), (ii) the guarantor subsidiaries of SDI, which includes Columbus since its acquisition on September 16, 2014, (iii) the non-guarantor subsidiaries of SDI, and (iv) the eliminations necessary to arrive at the information on a consolidated basis. The following statements should be read in conjunction with the accompanying consolidated financial statements and the company’s Annual Report on Form 10-K for the year ended December 31, 2013.
	Condensed Consolidating Balance Sheets (in thousands)
								Combined			Consolidating			Total
	As of September 30, 2014	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
	Cash and equivalents	$	74,925		$	70,695		$	13,971		$	—		$	159,591
	Accounts receivable, net	325,667			1,312,449			59,672			(639,120		)	1,058,668
	Inventories	695,441			856,685			115,089			(3,003		)	1,664,212
	Other current assets	52,092			7,761			6,289			(18,477		)	47,665
	Total current assets	1,148,125			2,247,590			195,021			(660,600		)	2,930,136
	Property, plant and equipment, net	1,020,150			1,846,279			556,490			(2,265		)	3,420,654
	Intangible assets, net	—			406,318			—			—			406,318
	Goodwill	—			727,128			—			—			727,128
	Other assets, including investments in subs	4,249,944			24,717			6,870			(4,187,484		)	94,047
	Total assets	$	6,418,219		$	5,252,032		$	758,381		$	(4,850,349	)	$	7,578,283
	Accounts payable	$	213,990		$	449,535		$	111,505		$	(134,909	)	$	640,121
	Accrued expenses	161,890			161,000			11,636			(64,965		)	269,561
	Current maturities of long-term debt	98,374			756			72,368			(39,640		)	131,858
	Total current liabilities	474,254			611,291			195,509			(239,514		)	1,041,540
	Long-term debt	2,894,071			624			184,044			(148,745		)	2,929,994
	Other liabilities	71,810			1,940,011			36,691			(1,479,752		)	568,760
	Redeemable noncontrolling interests	—			—			126,340			—			126,340
	Common stock	649			1,727,859			18,121			(1,745,980		)	649
	Treasury stock	(398,818		)	—			—			—			(398,818		)
	Additional paid-in-capital	1,075,593			117,737			601,282			(719,019		)	1,075,593
	Retained earnings (deficit)	2,300,660			854,510			(337,171		)	(517,339		)	2,300,660
	Total Steel Dynamics, Inc. equity	2,978,084			2,700,106			282,232			(2,982,338		)	2,978,084
	Noncontrolling interests	—			—			(66,435		)	—			(66,435		)
	Total equity	2,978,084			2,700,106			215,797			(2,982,338		)	2,911,649
	Total liabilities and equity	$	6,418,219		$	5,252,032		$	758,381		$	(4,850,349	)	$	7,578,283
								Combined			Consolidating			Total
	As of December 31, 2013	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
	Cash and equivalents	$	320,866		$	61,148		$	13,142		$	—		$	395,156
	Accounts receivable, net	309,691			874,707			32,018			(495,816		)	720,600
	Inventories	673,763			557,640			91,199			(7,855		)	1,314,747
	Other current assets	50,228			8,399			3,259			(18,755		)	43,131
	Total current assets	1,354,548			1,501,894			139,618			(522,426		)	2,473,634
	Property, plant and equipment, net	1,046,093			619,617			562,843			(2,419		)	2,226,134
	Intangible assets, net	—			386,159			—			—			386,159
	Goodwill	—			731,996			—			—			731,996
	Other assets, including investments in subs	2,630,411			21,789			8,092			(2,545,209		)	115,083
	Total assets	$	5,031,052		$	3,261,455		$	710,553		$	(3,070,054	)	$	5,933,006
	Accounts payable	$	160,255		$	258,406		$	60,987		$	(64,716	)	$	414,932
	Accrued expenses	142,055			115,182			10,694			(49,229		)	218,702
	Current maturities of long-term debt	315,521			300			52,163			(26,440		)	341,544
	Total current liabilities	617,831			373,888			123,844			(140,385		)	975,178
	Long-term debt	1,725,433			—			204,385			(163,773		)	1,766,045
	Other liabilities	140,465			1,986,260			34,895			(1,582,206		)	579,414
	Redeemable noncontrolling interest	—			—			116,514			—			116,514
	Common stock	645			33,896			18,121			(52,017		)	645
	Treasury stock	(718,529		)	—			—			—			(718,529		)
	Additional paid-in-capital	1,085,694			117,737			552,946			(670,683		)	1,085,694
	Retained earnings (deficit)	2,179,513			749,674			(288,684		)	(460,990		)	2,179,513
	Total Steel Dynamics, Inc. equity	2,547,323			901,307			282,383			(1,183,690		)	2,547,323
	Noncontrolling interests	—			—			(51,468		)	—			(51,468		)
	Total equity	2,547,323			901,307			230,915			(1,183,690		)	2,495,855
	Total liabilities and equity	$	5,031,052		$	3,261,455		$	710,553		$	(3,070,054	)	$	5,933,006
	Condensed Consolidating Statements of Operations (in thousands)
	For the three months ended,							Combined			Consolidating			Total
	September 30, 2014	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
	Net sales	$	1,044,207		$	2,609,731		$	150,551		$	(1,465,473	)	$	2,339,016
	Costs of goods sold	856,372			2,469,396			162,094			(1,437,358		)	2,050,504
	Gross profit (loss)	187,835			140,335			(11,543		)	(28,115		)	288,512
Selling, general and administrative	40,932			59,878			3,601			(4,542		)	99,869
Operating income (loss)	146,903			80,457			(15,144		)	(23,573		)	188,643
Interest expense, net of capitalized interest	18,965			12,238			1,958			(1,257		)	31,904
Other (income) expense, net	22,548			(202		)	(1,530		)	1,256			22,072
Income (loss) before income taxes and equity in net income of subsidiaries	105,390			68,421			(15,572		)	(23,572		)	134,667
Income taxes (benefit)	30,605			24,754			(561		)	(7,788		)	47,010
	74,785			43,667			(15,011		)	(15,784		)	87,657
Equity in net loss of subsidiaries	16,388			—			—			(16,388		)	—
Net loss attributable to noncontrolling interests	—			—			3,516			—			3,516
Net income (loss) attributable to Steel Dynamics, Inc.	$	91,173		$	43,667		$	(11,495	)	$	(32,172	)	$	91,173
For the three months ended,							Combined			Consolidating			Total
September 30, 2013	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
Net sales	$	902,280		$	2,136,327		$	91,198		$	(1,218,067	)	$	1,911,738
Costs of goods sold	760,589			2,025,470			114,408			(1,185,921		)	1,714,546
Gross profit (loss)	141,691			110,857			(23,210		)	(32,146		)	197,192
Selling, general and administrative	30,073			55,348			2,622			(4,124		)	83,919
Operating income (loss)	111,618			55,509			(25,832		)	(28,022		)	113,273
Interest expense, net of capitalized interest	19,733			10,561			1,915			(1,239		)	30,970
Other (income) expense, net	(2,423		)	631			(1,301		)	1,241			(1,852		)
Income (loss) before income taxes and equity in net loss of subsidiaries	94,308			44,317			(26,446		)	(28,024		)	84,155
Income taxes (benefit)	24,930			16,579			2,004			(10,448		)	33,065
	69,378			27,738			(28,450		)	(17,576		)	51,090
Equity in net loss of subsidiaries	(11,892		)	—			—			11,892			—
Net loss attributable to noncontrolling interests	—			—			6,396			—			6,396
Net income (loss) attributable to Steel Dynamics, Inc.	$	57,486		$	27,738		$	(22,054	)	$	(5,684	)	$	57,486
For the nine months ended,							Combined			Consolidating			Total
September 30, 2014	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
Net sales	$	2,915,339		$	7,035,579		$	377,639		$	(4,089,698	)	$	6,238,859
Costs of goods sold	2,477,791			6,668,153			427,029			(4,008,701		)	5,564,272
Gross profit (loss)	437,548			367,426			(49,390		)	(80,997		)	674,587
Selling, general and administrative	105,185			170,578			10,415			(13,071		)	273,107
Operating income (loss)	332,363			196,848			(59,805		)	(67,926		)	401,480
Interest expense, net of capitalized interest	57,357			33,093			5,824			(3,751		)	92,523
Other (income) expense, net	20,016			147			(4,226		)	3,750			19,687
Income (loss) before income taxes and equity in net loss of subsidiaries	254,990			163,608			(61,403		)	(67,925		)	289,270
Income taxes (benefit)	64,480			58,772			949			(22,627		)	101,574
	190,510			104,836			(62,352		)	(45,298		)	187,696
Equity in net loss of subsidiaries	11,545			—			—			(11,545		)	—
Net loss attributable to noncontrolling interests	—			—			14,359			—			14,359
Net income (loss) attributable to Steel Dynamics, Inc.	$	202,055		$	104,836		$	(47,993	)	$	(56,843	)	$	202,055
For the nine months ended,							Combined			Consolidating			Total
September 30, 2013	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
Net sales	$	2,566,286		$	6,150,327		$	245,607		$	(3,453,446	)	$	5,508,774
Costs of goods sold	2,220,737			5,840,025			318,163			(3,391,299		)	4,987,626
Gross profit (loss)	345,549			310,302			(72,556		)	(62,147		)	521,148
Selling, general and administrative	83,675			164,104			7,433			(12,767		)	242,445
Operating income (loss)	261,874			146,198			(79,989		)	(49,380		)	278,703
Interest expense, net of capitalized interest	61,927			33,351			5,405			(3,619		)	97,064
Other (income) expense, net	(4,776		)	645			(3,633		)	3,620			(4,144		)
Income (loss) before income taxes and equity in net loss of subsidiaries	204,723			112,202			(81,761		)	(49,381		)	185,783
Income taxes (benefit)	41,945			41,712			4,085			(17,574		)	70,168
	162,778			70,490			(85,846		)	(31,807		)	115,615
Equity in net loss of subsidiaries	(28,119		)	—			—			28,119			—
Net loss attributable to noncontrolling interests	—			—			19,044			—			19,044
Net income (loss) attributable to Steel Dynamics, Inc.	$	134,659		$	70,490		$	(66,802	)	$	(3,688	)	$	134,659
Condensed Consolidating Statements of Cash Flows (in thousands)
For the nine months ended,							Combined			Consolidating			Total
September 30, 2014	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
Net cash provided by (used in) operating activities	$	258,952		$	80,298		$	(41,245	)	$	(14	)	$	297,991
Net cash provided by (used in) investing activities	(1,692,967		)	15,023			(16,740		)	(1,528		)	(1,696,212		)
Net cash provided by (used in) financing activities	1,188,074			(85,774		)	58,814			1,542			1,162,656
Decrease in cash and equivalents	(245,941		)	9,547			829			—			(235,565		)
Cash and equivalents at beginning of period	320,866			61,148			13,142			—			395,156
Cash and equivalents at end of period	$	74,925		$	70,695		$	13,971		$	––		$	159,591
For the nine months ended,							Combined			Consolidating			Total
September 30, 2013	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
Net cash provided by (used in) operating activities	$	126,404		$	164,383		$	(56,636	)	$	11,540		$	245,691
Net cash used in investing activities	(115,979		)	(28,654		)	(20,230		)	53,760			(111,103		)
Net cash provided by (used in) financing activities	(10,920		)	(139,694		)	75,465			(65,300		)	(140,449		)
Decrease in cash and equivalents	(495		)	(3,965		)	(1,401		)	—			(5,861		)
Cash and equivalents at beginning of period	322,707			41,675			11,535			—			375,917
Cash and equivalents at end of period	$	322,212		$	37,710		$	10,134		$	––		$	370,056

Description_of_the_Business_an1

Description of the Business and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Description of the Business and Significant Accounting Policies	'
Principles of Consolidation	'
	Principles of Consolidation.  The consolidated financial statements include the accounts of SDI, together with its wholly and majority-owned or controlled subsidiaries, after elimination of significant intercompany accounts and transactions. Noncontrolling interests represent the noncontrolling owner’s proportionate share in the equity, income, or losses of the company’s majority-owned or controlled consolidated subsidiaries.
Use of Estimates	'
	Use of Estimates.  These financial statements are prepared in conformity with accounting principles generally accepted in the United States and, accordingly, include amounts that require management to make estimates and assumptions that affect the amounts reported in the financial statements and in the notes thereto. Significant items subject to such estimates and assumptions include the carrying value of property, plant and equipment, intangible assets and goodwill; valuation allowances for trade receivables, inventories and deferred income tax assets; unrecognized tax benefits; potential environmental liabilities; and litigation claims and settlements. Actual results may differ from these estimates and assumptions.
	In the opinion of management, these financial statements reflect all normal recurring adjustments necessary for a fair presentation of the interim period results. These financial statements and notes should be read in conjunction with the audited financial statements and notes thereto included in the company’s Annual Report on Form 10-K for the year ended December 31, 2013.
Goodwill	'
	Goodwill.  The company’s goodwill is allocated to the following reporting units at September 30, 2014, and December 31, 2013, (in thousands):
		September 30,		December 31,
		2014		2013
	OmniSource — Metals Recycling/Ferrous Resources Segment	$	553,379	$	558,247
	The Techs — Steel Segment	142,783		142,783
	Roanoke Bar Division — Steel Segment	29,041		29,041
	New Millennium Building Systems — Fabrication Segment	1,925		1,925
		$	727,128	$	731,996
	OmniSource goodwill decreased $4.9 million from December 31, 2013 to September 30, 2014, in recognition of the 2014 tax benefit related to the amortization of the component of OmniSource tax-deductible goodwill in excess of book goodwill.
	Additional goodwill, if any, allocated to Columbus may be determined after the accounting for the Columbus acquisition is completed (see Note 2).
Recently Issued Accounting Standards	'
	Recently Issued Accounting Standards.
	In May 2014, the FASB issued guidance codified in ASC 606, Revenue Recognition — Revenue from Contracts with Customers, which amends the guidance in former ASC 605, Revenue Recognition. The company is currently evaluating the impact of the provisions of ASC 606.
	In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements — Going Concern (Subtopic 205-40: Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern), effective for annual and interim periods ending after December 15, 2016. ASU 2014-15 requires management to evaluate whether there are conditions or events, considered in aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern within one year after the date that the financial statements are issued. There are required disclosures if substantial doubt is identified including documentation of principal conditions or events that raised substantial doubt about the entity’s ability to continue as a going concern (before consideration of management’s plans), management’s evaluation of the significance of those conditions or events in relation to the entity’s ability to meet its obligations, and management’s plans that alleviated substantial doubt about the entity’s ability to continue as a going concern. This ASU is not expected to have any impact on our overall results of operations, financial position or cash flows.

Description_of_the_Business_an2

Description of the Business and Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2014
Description of the Business and Significant Accounting Policies	'
Schedule of allocation of goodwill to reporting units	'
	The company’s goodwill is allocated to the following reporting units at September 30, 2014, and December 31, 2013, (in thousands):
		September 30,		December 31,
		2014		2013
	OmniSource — Metals Recycling/Ferrous Resources Segment	$	553,379	$	558,247
	The Techs — Steel Segment	142,783		142,783
	Roanoke Bar Division — Steel Segment	29,041		29,041
	New Millennium Building Systems — Fabrication Segment	1,925		1,925
		$	727,128	$	731,996

Acquisition_Tables

Acquisition (Tables)	9 Months Ended
	Sep. 30, 2014
Acquisition	'
Schedule of initial allocation of the purchase price	'
	The following initial allocation of the purchase price (in thousands) is preliminary. The accounting for the acquisition has not yet been completed because we have not finalized the valuations of the acquired assets, assumed liabilities and identifiable intangible assets, including goodwill, if any.
	Current assets, net of cash acquired	$	551,255
	Property, plant & equipment	1,298,065
	Intangible assets	40,000
	Other assets	3,682
	Total assets acquired	1,893,002
	Liabilities assumed	232,735
	Net assets acquired	$	1,660,267
Schedule of unaudited pro forma information	'
	The following unaudited pro forma information is presented below as if the Columbus acquisition was completed as of January 1, 2013, (in thousands, except per share amounts):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
	Net Sales	$	2,853,272	$	2,408,316	$	7,838,681	$	6,855,029
	Net Income attributable to Steel Dynamics, Inc.	$	137,516	$	57,948	$	299,681	$	84,118

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share	'
Schedule of reconciliation of the numerators and denominators used in calculating basic and diluted earnings per share	'
	The following table presents a reconciliation of the numerators and the denominators of the company’s basic and diluted earnings per share computations for net income attributable to Steel Dynamics, Inc. (in thousands, except per share data):
		Three Months Ended September 30,
		2014					2013
		Net Income		Shares	Per Share		Net Income		Shares	Per Share
		(Numerator)		(Denominator)	Amount		(Numerator)		(Denominator)	Amount
	Basic earnings per share	$	91,173	240,087	$	0.38	$	57,486	220,926	$	0.26
	Dilutive common share equivalents	—		2,157			—		1,366
	5.125% Convertible Senior Notes, net of tax	—		—			2,358		16,709
	Diluted earnings per share	$	91,173	242,244	$	0.38	$	59,844	239,001	$	0.25
		Nine Months Ended September 30,
		2014					2013
		Net Income		Shares	Per Share		Net Income		Shares	Per Share
		(Numerator)		(Denominator)	Amount		(Numerator)		(Denominator)	Amount
	Basic earnings per share	$	202,055	229,772	$	0.88	$	134,659	220,464	$	0.61
	Dilutive common share equivalents	—		1,852			—		1,363
	5.125% Convertible Senior Notes, net of tax	4,327		10,271			7,074		16,670
	Diluted earnings per share	$	206,382	241,895	$	0.85	$	141,733	238,497	$	0.59

Inventories_Tables

Inventories (Tables)	9 Months Ended
	Sep. 30, 2014
Inventories	'
Schedule of inventories	'
	Inventory consisted of the following (in thousands):
		September 30,		December 31,
		2014		2013
	Raw materials	$	766,209	$	660,384
	Supplies	365,504		293,533
	Work in progress	148,712		84,710
	Finished goods	383,787		276,120
	Total inventories	$	1,664,212	$	1,314,747

Changes_in_Equity_Tables

Changes in Equity (Tables)	9 Months Ended
	Sep. 30, 2014
Changes in Equity	'
Schedule of stockholders' equity	'
		Stockholders of Steel Dynamics, Inc.
		Common		Additional			Retained			Treasury			Noncontrolling			Total			Redeemable
				Paid-In															Noncontrolling
		Stock		Capital			Earnings			Stock			Interests			Equity			Interests
	Balances at January 1, 2014	$	645	$	1,085,694		$	2,179,513		$	(718,529	)	$	(51,468	)	$	2,495,855		$	116,514
	Proceeds from the exercise of stock options, including related tax effect	4		23,075			—			—			—			23,079			—
	Dividends declared	—		—			(80,863		)	—			—			(80,863		)	—
	Conversion of 5.125% Convertible Senior Notes	—		(45,650		)	—			317,451			—			271,801			—
	Equity-based compensation and issuance of restricted stock	—		12,474			(45		)	2,260			—			14,689			—
	Contributions from noncontrolling investors	—		—			—			—			97			97			9,826
	Distributions to noncontrolling investors	—		—			—			—			(705		)	(705		)	—
	Net income (loss)	—		—			202,055			—			(14,359		)	187,696			—
	Balances at September 30, 2014	$	649	$	1,075,593		$	2,300,660		$	(398,818	)	$	(66,435	)	$	2,911,649		$	126,340

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2014
Derivative Financial Instruments	'
Commodity option and futures contract commitments for non monetary notional amount	'
	The following summarizes the company’s futures contract commitments as of September 30, 2014 (MT represents metric tons and Lbs represents pounds):
	Commodity Futures	Long/Short	Total
	Aluminum	Long	3,300		MT
	Aluminum	Short	3,975		MT
	Copper	Long	6,226		MT
	Copper	Short	18,296		MT
	Silver	Short	343		Lbs
Summary of the location and amounts of the fair values and gains or losses related to derivatives included in the entity's financial statements	'
	The following summarizes the location and amounts of the fair values reported on the company’s balance sheets as of September 30, 2014, and December 31, 2013, and gains and losses related to derivatives included in the company’s statement of income for the three- and nine-month periods ended September 30, 2014 and 2013 (in thousands):
		Asset Derivatives							Liability Derivatives
			Fair Value						Fair Value
		Balance sheet location	September 30,			December 31, 2013			September 30,			December 31, 2013
			2014						2014
	Derivative instruments designated as fair value hedges -
	Commodity futures	Other current assets	$	3,373		$	658		$	528		$	1,886
	Derivative instruments not designated as hedges -
	Commodity futures	Other current assets	$	1,757		$	352		$	697		2,601
	Total derivative instruments		$	5,130		$	1,010		$	1,225		$	4,487
		Location of gain (loss)	Amount of gain (loss) recognized						Hedged items		Location of gain (loss)		Amount of gain (loss) recognized
			in income on derivatives for the										in income on related hedged items
			three months ended										for the three months ended
		recognized in income	September 30,			September 30,			in fair value hedge		recognized in income		September 30,			September 30,
		on derivatives	2014			2013			relationships		on related hedged item		2014			2013
	Derivatives in fair value hedging relationships -
	Commodity futures	Costs of goods sold	$	4,371		$	381		Firm commitments		Costs of goods sold		$	784		$	(1,736	)
									Inventory		Costs of goods sold		(4,163		)	364
													$	(3,379	)	$	(1,372	)
	Derivatives not designated as hedging instruments -
	Commodity futures	Costs of goods sold	$	2,672		$	(2,836	)
		Location of gain (loss)	Amount of gain recognized in						Hedged items		Location of gain (loss)		Amount of gain (loss) recognized in
			income on derivatives for the nine										income on related hedged items for
			months ended										the nine months ended
		recognized in income on	September 30,			September 30,			in fair value hedge		recognized in income on		September 30,			September 30,
		derivatives	2014			2013			relationships		related hedged item		2014			2013
	Derivatives in fair value hedging relationships -
	Commodity futures	Costs of goods sold	$	3,356		$	7,773		Firm commitments		Costs of goods sold		$	1,115		$	877
									Inventory		Costs of goods sold		(3,805		)	(8,458		)
													$	(2,690	)	$	(7,581	)
	Derivatives not designated as hedging instruments -
	Commodity futures	Costs of goods sold	$	8,598		$	3,793

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Measurements	'
Schedule of assets and liabilities measured at fair value on a recurring basis	'
	The following table sets forth financial assets and liabilities measured at fair value in the consolidated balance sheets and the respective levels to which the fair value measurements are classified within the fair value hierarchy as of  September 30, 2014, and December 31, 2013 (in thousands):
		Total		Quoted Prices in		Significant		Significant
				Active Markets		Other		Unobservable
				for Identical		Observable		Inputs
				Assets		Inputs		(Level 3)
				(Level 1)		(Level 2)
	September 30, 2014
	Commodity futures — financial assets	$	5,130	$	—	$	5,130	$	—
	Commodity futures — financial liabilities	1,225		—		1,225		—
	December 31, 2013
	Commodity futures — financial assets	$	1,010	$	—	$	1,010	$	—
	Commodity futures — financial liabilities	4,487		—		4,487		—

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Information	'
Schedule of operating segment results	'
	The company’s segment results for the three- and nine-month periods ended September 30, 2014 and 2013 are as follows (in thousands):
	For the three months ended					Metals Recycling /			Steel Fabrication
	September 30, 2014		Steel Operations			Ferrous Resources			Operations		Other			Eliminations			Consolidated
	Net Sales
	External		$	1,400,370		$	609,098		$	189,993	$	25,084		$	—		$	2,224,545
	External Non-U.S.		50,842			63,299			—		330			—			114,471
	Other segments		75,320			326,090			43		8,340			(409,793		)	—
			1,526,532			998,487			190,036		33,754			(409,793		)	2,339,016
	Operating income (loss)		200,116			(5,330		)	19,474		(26,733		)(1)	1,116		-2	188,643
	Income (loss) before income taxes		184,589			(11,724		)	17,877		(57,191		)(7)	1,116			134,667
	Depreciation and amortization		32,998			28,775			2,974		1,262			(52		)	65,957
	Capital expenditures		12,195			11,599			477		260			—			24,531
	As of September 30, 2014
	Assets		4,553,924			2,531,821			315,381		427,654		-3	(250,497		)(4)	7,578,283
	Liabilities		821,796			651,128			34,386		3,273,198		-5	(240,214		)(6)	4,540,294
	Footnotes related to the three months ended September 30, 2014 segment results (in millions):
	-1	Corporate SG&A		$	(12.4	)
		Company-wide equity-based compensation		(5.1		)
		Profit sharing		(11.6		)
		Other, net		2.4
				$	(26.7	)
	-2	Gross profit increase from intra-company sales		$	1.1
	-3	Cash and equivalents		$	80.3
		Accounts receivable		12.8
		Inventories		15.2
		Deferred income taxes		18.3
		Property, plant and equipment, net		70.2
		Debt issuance costs		39.6
		Intra-company debt		160.2
		Other		31.1
				$	427.7
	-4	Elimination of intra-company receivables		$	(80.7	)
		Elimination of intra-company debt		(160.2		)
		Other		(9.6		)
				$	(250.5	)
	-5	Accounts payable		$	76.9
		Income taxes payable		26.9
		Accrued interest		21.1
		Accrued profit sharing		25.2
		Debt		2,990.20
		Deferred income taxes		97.4
		Other		35.5
				$	3,273.20
	-6	Elimination of intra-company payables		$	(81.2	)
		Elimination of intra-company debt		(160.2		)
		Other		1.2
				$	(240.2	)
	-7	Includes $25.0 million of acquisition and bridge financing costs associated with the acquisition of Columbus.
	For the three months ended					Metals Recycling /			Steel Fabrication
	September 30, 2013		Steel Operations			Ferrous Resources			Operations		Other			Eliminations			Consolidated
	Net Sales
	External		$	1,102,048		$	557,765		$	119,134	$	24,593		$	—		$	1,803,540
	External Non-U.S.		60,381			47,616			—		201			—			108,198
	Other segments		54,537			313,113			134		7,918			(375,702		)	—
			1,216,966			918,494			119,268		32,712			(375,702		)	1,911,738
	Operating income (loss)		146,564			(17,135		)	3,265		(17,274		)(1)	(2,147		)(2)	113,273
	Income (loss) before income taxes		133,041			(24,567		)	1,751		(23,922		)	(2,148		)	84,155
	Depreciation and amortization		26,815			27,713			2,219		1,506			(51		)	58,202
	Capital expenditures		33,985			17,385			297		495			—			52,162
	As of September 30, 2013
	Assets		2,581,798			2,530,979			272,786		699,244		-3	(210,502		)(4)	5,874,305
	Liabilities		533,966			593,674			22,908		2,366,273		-5	(200,304		)(6)	3,316,517
	Footnotes related to the three months ended September 30, 2013 segment results (in millions):
-1	Corporate SG&A		$	(9.2	)
	Company-wide equity-based compensation		(2.1		)
	Profit sharing		(7.4		)
	Other, net		1.4
	Total		$	(17.3	)
-2	Gross profit reduction from intra-company sales		$	(2.1	)
-3	Cash and equivalents		$	325.8
	Accounts receivable		13.4
	Inventories		14
	Deferred income taxes		25.2
	Property, plant and equipment, net		72.9
	Debt issuance costs, net		27.7
	Intra-company debt		153.6
	Other		66.6
	Total		$	699.2
-4	Elimination of intra-company receivables		$	(46.9	)
	Elimination of intra-company debt		(153.6		)
	Other		(10.0		)
	Total		$	(210.5	)
-5	Accounts payable		$	43.1
	Income taxes payable		7.7
	Accrued interest		22.9
	Accrued profit sharing		19.5
	Debt		2,041.80
	Deferred income taxes		204.6
	Other		26.7
	Total		$	2,366.30
-6	Elimination of intra-company payables		$	(47.3	)
	Elimination of intra-company debt		(153.6		)
	Other		0.6
	Total		$	(200.3	)
For the nine months ended					Metals Recycling /			Steel Fabrication
September 30, 2014		Steel Operations			Ferrous Resources			Operations		Other			Eliminations			Consolidated
Net Sales
External		$	3,675,696		$	1,714,440		$	440,706	$	69,886		$	—		$	5,900,728
External Non-U.S.		158,218			178,947			—		966			—			338,131
Other segments		188,854			973,635			43		22,322			(1,184,854		)	—
		4,022,768			2,867,022			440,749		93,174			(1,184,854		)	6,238,859
Operating income (loss)		461,708			(26,902		)	30,190		(67,437		)(1)	3,921		-2	401,480
Income (loss) before income taxes		419,181			(47,054		)	25,628		(112,406		)(3)	3,921			289,270
Depreciation and amortization		89,244			81,266			7,597		4,013			(154		)	181,966
Capital expenditures		47,133			33,762			1,324		687			—			82,906
Footnotes related to the nine months ended September 30, 2014 segment results (in millions):
-1	Corporate SG&A		$	(31.7	)
	Company-wide equity-based compensation		(14.4		)
	Profit sharing		(25.2		)
	Other, net		3.9
	Total		$	(67.4	)
-2	Gross profit increase from intra-company sales		$	3.9
-3	Includes $25.0 million of acquisition and bridge financing costs associated with the acquisition of Columbus.
For the nine months ended					Metals Recycling /			Steel Fabrication
September 30, 2013		Steel Operations			Ferrous Resources			Operations		Other			Eliminations			Consolidated
Net Sales
External		$	3,152,111		$	1,653,975		$	316,526	$	64,792		$	—		$	5,187,404
External Non-U.S.		162,646			158,026			—		698			—			321,370
Other segments		168,482			865,143			1,276		20,198			(1,055,099		)	—
		3,483,239			2,677,144			317,802		85,688			(1,055,099		)	5,508,774
Operating income (loss)		351,410			(34,210		)	7,125		(48,147		)(1)	2,525		-2	278,703
Income (loss) before income taxes		309,780			(56,860		)	2,475		(72,136		)	2,524			185,783
Depreciation and amortization		79,698			81,553			6,455		4,536			(153		)	172,089
Capital expenditures		93,244			49,999			2,000		1,501			—			146,744
Footnotes related to the nine months ended September 30, 2013 segment results (in millions):
-1	Corporate SG&A		$	(26.3	)
	Company-wide equity-based compensation		(7.3		)
	Profit sharing		(16.5		)
	Other, net		2
	Total		$	(48.1	)
-2	Gross profit increase from intra-company sales		$	2.5

Condensed_Consolidating_Inform1

Condensed Consolidating Information (Tables)	9 Months Ended
	Sep. 30, 2014
Condensed Consolidating Information	'
Schedule of Condensed Consolidating Balance Sheets	'
	Condensed Consolidating Balance Sheets (in thousands)
								Combined			Consolidating			Total
	As of September 30, 2014	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
	Cash and equivalents	$	74,925		$	70,695		$	13,971		$	—		$	159,591
	Accounts receivable, net	325,667			1,312,449			59,672			(639,120		)	1,058,668
	Inventories	695,441			856,685			115,089			(3,003		)	1,664,212
	Other current assets	52,092			7,761			6,289			(18,477		)	47,665
	Total current assets	1,148,125			2,247,590			195,021			(660,600		)	2,930,136
	Property, plant and equipment, net	1,020,150			1,846,279			556,490			(2,265		)	3,420,654
	Intangible assets, net	—			406,318			—			—			406,318
	Goodwill	—			727,128			—			—			727,128
	Other assets, including investments in subs	4,249,944			24,717			6,870			(4,187,484		)	94,047
	Total assets	$	6,418,219		$	5,252,032		$	758,381		$	(4,850,349	)	$	7,578,283
	Accounts payable	$	213,990		$	449,535		$	111,505		$	(134,909	)	$	640,121
	Accrued expenses	161,890			161,000			11,636			(64,965		)	269,561
	Current maturities of long-term debt	98,374			756			72,368			(39,640		)	131,858
	Total current liabilities	474,254			611,291			195,509			(239,514		)	1,041,540
	Long-term debt	2,894,071			624			184,044			(148,745		)	2,929,994
	Other liabilities	71,810			1,940,011			36,691			(1,479,752		)	568,760
	Redeemable noncontrolling interests	—			—			126,340			—			126,340
	Common stock	649			1,727,859			18,121			(1,745,980		)	649
	Treasury stock	(398,818		)	—			—			—			(398,818		)
	Additional paid-in-capital	1,075,593			117,737			601,282			(719,019		)	1,075,593
	Retained earnings (deficit)	2,300,660			854,510			(337,171		)	(517,339		)	2,300,660
	Total Steel Dynamics, Inc. equity	2,978,084			2,700,106			282,232			(2,982,338		)	2,978,084
	Noncontrolling interests	—			—			(66,435		)	—			(66,435		)
	Total equity	2,978,084			2,700,106			215,797			(2,982,338		)	2,911,649
	Total liabilities and equity	$	6,418,219		$	5,252,032		$	758,381		$	(4,850,349	)	$	7,578,283
								Combined			Consolidating			Total
	As of December 31, 2013	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
	Cash and equivalents	$	320,866		$	61,148		$	13,142		$	—		$	395,156
	Accounts receivable, net	309,691			874,707			32,018			(495,816		)	720,600
	Inventories	673,763			557,640			91,199			(7,855		)	1,314,747
	Other current assets	50,228			8,399			3,259			(18,755		)	43,131
	Total current assets	1,354,548			1,501,894			139,618			(522,426		)	2,473,634
	Property, plant and equipment, net	1,046,093			619,617			562,843			(2,419		)	2,226,134
	Intangible assets, net	—			386,159			—			—			386,159
	Goodwill	—			731,996			—			—			731,996
	Other assets, including investments in subs	2,630,411			21,789			8,092			(2,545,209		)	115,083
	Total assets	$	5,031,052		$	3,261,455		$	710,553		$	(3,070,054	)	$	5,933,006
	Accounts payable	$	160,255		$	258,406		$	60,987		$	(64,716	)	$	414,932
	Accrued expenses	142,055			115,182			10,694			(49,229		)	218,702
	Current maturities of long-term debt	315,521			300			52,163			(26,440		)	341,544
	Total current liabilities	617,831			373,888			123,844			(140,385		)	975,178
	Long-term debt	1,725,433			—			204,385			(163,773		)	1,766,045
	Other liabilities	140,465			1,986,260			34,895			(1,582,206		)	579,414
	Redeemable noncontrolling interest	—			—			116,514			—			116,514
	Common stock	645			33,896			18,121			(52,017		)	645
	Treasury stock	(718,529		)	—			—			—			(718,529		)
	Additional paid-in-capital	1,085,694			117,737			552,946			(670,683		)	1,085,694
	Retained earnings (deficit)	2,179,513			749,674			(288,684		)	(460,990		)	2,179,513
	Total Steel Dynamics, Inc. equity	2,547,323			901,307			282,383			(1,183,690		)	2,547,323
	Noncontrolling interests	—			—			(51,468		)	—			(51,468		)
	Total equity	2,547,323			901,307			230,915			(1,183,690		)	2,495,855
	Total liabilities and equity	$	5,031,052		$	3,261,455		$	710,553		$	(3,070,054	)	$	5,933,006
Schedule of Condensed Consolidating Statements of Operations	'
	Condensed Consolidating Statements of Operations (in thousands)
	For the three months ended,							Combined			Consolidating			Total
	September 30, 2014	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
	Net sales	$	1,044,207		$	2,609,731		$	150,551		$	(1,465,473	)	$	2,339,016
	Costs of goods sold	856,372			2,469,396			162,094			(1,437,358		)	2,050,504
	Gross profit (loss)	187,835			140,335			(11,543		)	(28,115		)	288,512
	Selling, general and administrative	40,932			59,878			3,601			(4,542		)	99,869
	Operating income (loss)	146,903			80,457			(15,144		)	(23,573		)	188,643
	Interest expense, net of capitalized interest	18,965			12,238			1,958			(1,257		)	31,904
	Other (income) expense, net	22,548			(202		)	(1,530		)	1,256			22,072
	Income (loss) before income taxes and equity in net income of subsidiaries	105,390			68,421			(15,572		)	(23,572		)	134,667
	Income taxes (benefit)	30,605			24,754			(561		)	(7,788		)	47,010
		74,785			43,667			(15,011		)	(15,784		)	87,657
	Equity in net loss of subsidiaries	16,388			—			—			(16,388		)	—
	Net loss attributable to noncontrolling interests	—			—			3,516			—			3,516
	Net income (loss) attributable to Steel Dynamics, Inc.	$	91,173		$	43,667		$	(11,495	)	$	(32,172	)	$	91,173
	For the three months ended,							Combined			Consolidating			Total
	September 30, 2013	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
	Net sales	$	902,280		$	2,136,327		$	91,198		$	(1,218,067	)	$	1,911,738
	Costs of goods sold	760,589			2,025,470			114,408			(1,185,921		)	1,714,546
	Gross profit (loss)	141,691			110,857			(23,210		)	(32,146		)	197,192
	Selling, general and administrative	30,073			55,348			2,622			(4,124		)	83,919
	Operating income (loss)	111,618			55,509			(25,832		)	(28,022		)	113,273
	Interest expense, net of capitalized interest	19,733			10,561			1,915			(1,239		)	30,970
	Other (income) expense, net	(2,423		)	631			(1,301		)	1,241			(1,852		)
	Income (loss) before income taxes and equity in net loss of subsidiaries	94,308			44,317			(26,446		)	(28,024		)	84,155
	Income taxes (benefit)	24,930			16,579			2,004			(10,448		)	33,065
		69,378			27,738			(28,450		)	(17,576		)	51,090
	Equity in net loss of subsidiaries	(11,892		)	—			—			11,892			—
	Net loss attributable to noncontrolling interests	—			—			6,396			—			6,396
	Net income (loss) attributable to Steel Dynamics, Inc.	$	57,486		$	27,738		$	(22,054	)	$	(5,684	)	$	57,486
	For the nine months ended,							Combined			Consolidating			Total
	September 30, 2014	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
	Net sales	$	2,915,339		$	7,035,579		$	377,639		$	(4,089,698	)	$	6,238,859
	Costs of goods sold	2,477,791			6,668,153			427,029			(4,008,701		)	5,564,272
	Gross profit (loss)	437,548			367,426			(49,390		)	(80,997		)	674,587
	Selling, general and administrative	105,185			170,578			10,415			(13,071		)	273,107
	Operating income (loss)	332,363			196,848			(59,805		)	(67,926		)	401,480
	Interest expense, net of capitalized interest	57,357			33,093			5,824			(3,751		)	92,523
	Other (income) expense, net	20,016			147			(4,226		)	3,750			19,687
	Income (loss) before income taxes and equity in net loss of subsidiaries	254,990			163,608			(61,403		)	(67,925		)	289,270
	Income taxes (benefit)	64,480			58,772			949			(22,627		)	101,574
		190,510			104,836			(62,352		)	(45,298		)	187,696
	Equity in net loss of subsidiaries	11,545			—			—			(11,545		)	—
	Net loss attributable to noncontrolling interests	—			—			14,359			—			14,359
	Net income (loss) attributable to Steel Dynamics, Inc.	$	202,055		$	104,836		$	(47,993	)	$	(56,843	)	$	202,055
	For the nine months ended,							Combined			Consolidating			Total
	September 30, 2013	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
	Net sales	$	2,566,286		$	6,150,327		$	245,607		$	(3,453,446	)	$	5,508,774
	Costs of goods sold	2,220,737			5,840,025			318,163			(3,391,299		)	4,987,626
	Gross profit (loss)	345,549			310,302			(72,556		)	(62,147		)	521,148
	Selling, general and administrative	83,675			164,104			7,433			(12,767		)	242,445
	Operating income (loss)	261,874			146,198			(79,989		)	(49,380		)	278,703
	Interest expense, net of capitalized interest	61,927			33,351			5,405			(3,619		)	97,064
	Other (income) expense, net	(4,776		)	645			(3,633		)	3,620			(4,144		)
	Income (loss) before income taxes and equity in net loss of subsidiaries	204,723			112,202			(81,761		)	(49,381		)	185,783
	Income taxes (benefit)	41,945			41,712			4,085			(17,574		)	70,168
		162,778			70,490			(85,846		)	(31,807		)	115,615
	Equity in net loss of subsidiaries	(28,119		)	—			—			28,119			—
	Net loss attributable to noncontrolling interests	—			—			19,044			—			19,044
	Net income (loss) attributable to Steel Dynamics, Inc.	$	134,659		$	70,490		$	(66,802	)	$	(3,688	)	$	134,659
Schedule of Condensed Consolidating Statements of Cash Flows	'
	Condensed Consolidating Statements of Cash Flows (in thousands)
	For the nine months ended,							Combined			Consolidating			Total
	September 30, 2014	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
	Net cash provided by (used in) operating activities	$	258,952		$	80,298		$	(41,245	)	$	(14	)	$	297,991
	Net cash provided by (used in) investing activities	(1,692,967		)	15,023			(16,740		)	(1,528		)	(1,696,212		)
	Net cash provided by (used in) financing activities	1,188,074			(85,774		)	58,814			1,542			1,162,656
	Decrease in cash and equivalents	(245,941		)	9,547			829			—			(235,565		)
	Cash and equivalents at beginning of period	320,866			61,148			13,142			—			395,156
	Cash and equivalents at end of period	$	74,925		$	70,695		$	13,971		$	––		$	159,591
	For the nine months ended,							Combined			Consolidating			Total
	September 30, 2013	Parent			Guarantors			Non-Guarantors			Adjustments			Consolidated
	Net cash provided by (used in) operating activities	$	126,404		$	164,383		$	(56,636	)	$	11,540		$	245,691
	Net cash used in investing activities	(115,979		)	(28,654		)	(20,230		)	53,760			(111,103		)
	Net cash provided by (used in) financing activities	(10,920		)	(139,694		)	75,465			(65,300		)	(140,449		)
	Decrease in cash and equivalents	(495		)	(3,965		)	(1,401		)	—			(5,861		)
	Cash and equivalents at beginning of period	322,707			41,675			11,535			—			375,917
	Cash and equivalents at end of period	$	322,212		$	37,710		$	10,134		$	––		$	370,056

Description_of_the_Business_an3

Description of the Business and Significant Accounting Policies (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Description of the Business and Significant Accounting Policies	'	'	'	'
Number of reporting segments	'	'	3	'
Steel Operations	'	'	'	'
Segment Reporting Information	'	'	'	'
Percentage of external net sales	62.00%	61.00%	61.00%	60.00%
Metals Recycling/Ferrous Resources	'	'	'	'
Segment Reporting Information	'	'	'	'
Percentage of external net sales	29.00%	32.00%	30.00%	33.00%
Number of iron making initiatives	'	'	2	'
Steel Fabrication Operations	'	'	'	'
Segment Reporting Information	'	'	'	'
Percentage of external net sales	8.00%	6.00%	7.00%	6.00%
Number of New Millennium Building Systems joist and deck plants	'	'	6	'

Description_of_the_Business_an4

Description of the Business and Significant Accounting Policies (Details 2) (USD $)	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Goodwill	'	'
Goodwill	$727,128,000	$731,996,000
Omni Source - Metals Recycling/Ferrous Resources Segment	'	'
Goodwill	'	'
Goodwill	553,379,000	558,247,000
Goodwill decrease due to tax benefit related to the amortization of the component	4,900,000	'
The Techs - Steel Segment	'	'
Goodwill	'	'
Goodwill	142,783,000	142,783,000
Roanoke Bar Division - Steel Segment	'	'
Goodwill	'	'
Goodwill	29,041,000	29,041,000
New Millennium Building Systems - Fabrication Segment	'	'
Goodwill	'	'
Goodwill	$1,925,000	$1,925,000

Acquisition_Details

Acquisition (Details) (Severstal Columbus LLC, USD $)	0 Months Ended		3 Months Ended		9 Months Ended
	Sep. 16, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 16, 2014
	MT
Business Acquisition Information	'	'	'	'	'	'	'
Business acquisition percentage	'	'	'	'	'	'	100.00%
Purchase price	$1,625,000,000	'	'	'	'	'	'
Working capital adjustments	35,300,000	'	'	'	'	'	'
Additional production capacity due to acquisition (in million tons)	3.4	'	'	'	'	'	'
Revenue since acquisition	'	126,500,000	'	'	'	'	'
Pre-tax income since acquisition	'	13,500,000	'	'	'	'	'
Purchase accounting related expenses	'	14,500,000	'	'	'	'	'
Acquisition and related costs	'	'	25,000,000	'	25,000,000	'	'
Net assets acquired	'	'	'	'	'	'	'
Current assets, net of cash acquired	'	'	'	'	'	'	551,255,000
Property, plant & equipment	'	'	'	'	'	'	1,298,065,000
Intangible assets	'	'	'	'	'	'	40,000,000
Other assets	'	'	'	'	'	'	3,682,000
Total assets acquired	'	'	'	'	'	'	1,893,002,000
Liabilities assumed	'	'	'	'	'	'	232,735,000
Net assets acquired	'	'	'	'	'	'	1,660,267,000
Amortization of intangible assets	'	'	'	'	'	'	'
Expected life	'10 years	'	'	'	'	'	'
Unaudited pro forma results	'	'	'	'	'	'	'
Net sales	'	'	2,853,272,000	2,408,316,000	7,838,681,000	6,855,029,000	'
Net Income attributable to Steel Dynamics, Inc.	'	'	137,516,000	57,948,000	299,681,000	84,118,000	'
Pro forma step-up inventory expense	'	'	'	'	'	17,700,000	'
Pro forma acquisition costs	'	'	'	'	'	25,000,000	'
Customer Relationships	'	'	'	'	'	'	'
Amortization of intangible assets	'	'	'	'	'	'	'
Preliminary intangible assets	40,000,000	'	'	'	'	'	'
Senior Notes	'	'	'	'	'	'	'
Business Acquisition Information	'	'	'	'	'	'	'
Issuance of Senior Notes	$1,200,000,000	'	'	'	'	'	$1,200,000,000

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended				9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jun. 15, 2014	Jun. 12, 2014	Sep. 30, 2014	Sep. 30, 2013
					5.125% convertible senior notes, due 2014	5.125% convertible senior notes, due 2014	Options	Options
Antidilutive securities excluded from computation of earnings per share amount	'	'	'	'	'	'	'	'
Stated interest rate (as a percent)	'	'	'	'	5.13%	5.13%	'	'
Antidilutive securities excluded from computation of earnings per share amount (in shares)	'	'	'	'	'	'	0	2,400,000
Net Income (Numerator)	'	'	'	'	'	'	'	'
Basic earnings - net income (loss) (in dollars)	$91,173	$57,486	$202,055	$134,659	'	'	'	'
5.125% convertible senior notes, net of tax (in dollars)	'	2,358	4,327	7,074	'	'	'	'
Diluted earnings - net income (loss) (in dollars)	$91,173	$59,844	$206,382	$141,733	'	'	'	'
Shares (Denominator)	'	'	'	'	'	'	'	'
Weighted average common shares outstanding (in shares)	240,087,000	220,926,000	229,772,000	220,464,000	'	'	'	'
Dilutive common share equivalents (in shares)	2,157,000	1,366,000	1,852,000	1,363,000	'	'	'	'
5.125% convertible senior notes, net of tax (in shares)	'	16,709,000	10,271,000	16,670,000	'	'	'	'
Weighted average common shares outstanding - diluted (in shares)	242,244,000	239,001,000	241,895,000	238,497,000	'	'	'	'
Per Share Amount	'	'	'	'	'	'	'	'
Basic earnings per share (in dollars per share)	$0.38	$0.26	$0.88	$0.61	'	'	'	'
Diluted earnings per share (in dollars per share)	$0.38	$0.25	$0.85	$0.59	'	'	'	'

Inventories_Details

Inventories (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventories	'	'
Raw materials	$766,209	$660,384
Supplies	365,504	293,533
Work in progress	148,712	84,710
Finished goods	383,787	276,120
Total inventories	$1,664,212	$1,314,747

Debt_Details

Debt (Details) (USD $)

3 Months Ended

9 Months Ended

0 Months Ended

0 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 09, 2014

Sep. 09, 2014

Jun. 16, 2014

Jun. 12, 2014

Jun. 15, 2014

Jun. 12, 2014

Sep. 09, 2014

Sep. 09, 2014

Sep. 09, 2014

Sep. 09, 2014

Sep. 09, 2014

Sep. 09, 2014

Sep. 09, 2014

Sep. 09, 2014

Sep. 09, 2014

Senior Notes 5.125% due 2021

Senior Notes 5.500% due 2024

5.125% convertible senior notes, due 2014

5.125% convertible senior notes, due 2014

5.125% convertible senior notes, due 2014

5.125% convertible senior notes, due 2014

Debt Instrument Redemption Period One

Debt Instrument Redemption Period One

Debt Instrument Redemption Period Two

Debt Instrument Redemption Period Two

Debt Instrument Redemption Period Three

Debt Instrument Redemption Period Three

Debt Instrument Redemption Period Four

Debt Instrument Redemption Period Four

Debt Instrument Redemption Period Five

Senior Notes 5.125% due 2021

Senior Notes 5.500% due 2024

Senior Notes 5.125% due 2021

Senior Notes 5.500% due 2024

Senior Notes 5.125% due 2021

Senior Notes 5.500% due 2024

Senior Notes 5.125% due 2021

Senior Notes 5.500% due 2024

Senior Notes 5.500% due 2024

Debt Information

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt issued

'

'

'

'

$700,000,000

$500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Stated interest rate (as a percent)

'

'

'

'

5.13%

5.50%

'

'

5.13%

5.13%

'

'

'

'

'

'

'

'

'

Redemption price of debt instrument (as a percent)

'

'

'

'

'

'

'

'

'

'

105.13%

105.50%

102.56%

102.75%

101.28%

101.83%

100.00%

100.92%

100.00%

Maximum redemption of debt instrument (as a percent)

'

'

'

'

'

'

'

'

'

'

35.00%

35.00%

'

'

'

'

'

'

'

Principal amount of debt converted

'

'

'

'

'

'

'

271,800,000

'

'

'

'

'

'

'

'

'

'

'

Convertible debt rate, basis for conversion

'

'

'

'

'

'

'

0.0584731

'

'

'

'

'

'

'

'

'

'

'

Conversion price per share (in dollars per share)

'

'

'

'

'

'

'

'

'

$17.10

'

'

'

'

'

'

'

'

'

Shares issued upon conversion

'

'

'

'

'

'

'

15,893,457

'

'

'

'

'

'

'

'

'

'

'

Remaining outstanding Notes paid in cash

$138,533,000

$4,097,000

$271,191,000

$512,100,000

'

'

$15,700,000

'

'

'

'

'

'

'

'

'

'

'

'

Changes_in_Equity_Details

Changes in Equity (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Increase (Decrease) in Equity	'	'	'	'
Balances	'	'	$2,495,855	'
Proceeds from the exercise of stock options, including related tax effect	'	'	23,079	'
Dividends declared	'	'	-80,863	'
Conversion of 5.125% convertible senior notes	'	'	271,801	'
Equity based compensation and issuance of restricted stock	'	'	14,689	'
Contributions from noncontrolling investors	'	'	97	'
Distributions to noncontrolling investors	'	'	-705	'
Net income (loss)	87,657	51,090	187,696	115,615
Balances	2,911,649	'	2,911,649	'
Common Stock	'	'	'	'
Increase (Decrease) in Equity	'	'	'	'
Balances	'	'	645	'
Proceeds from the exercise of stock options, including related tax effect	'	'	4	'
Balances	649	'	649	'
Additional Paid-in Capital	'	'	'	'
Increase (Decrease) in Equity	'	'	'	'
Balances	'	'	1,085,694	'
Proceeds from the exercise of stock options, including related tax effect	'	'	23,075	'
Conversion of 5.125% convertible senior notes	'	'	-45,650	'
Equity based compensation and issuance of restricted stock	'	'	12,474	'
Balances	1,075,593	'	1,075,593	'
Retained Earnings	'	'	'	'
Increase (Decrease) in Equity	'	'	'	'
Balances	'	'	2,179,513	'
Dividends declared	'	'	-80,863	'
Equity based compensation and issuance of restricted stock	'	'	-45	'
Net income (loss)	'	'	202,055	'
Balances	2,300,660	'	2,300,660	'
Treasury Stock	'	'	'	'
Increase (Decrease) in Equity	'	'	'	'
Balances	'	'	-718,529	'
Conversion of 5.125% convertible senior notes	'	'	317,451	'
Equity based compensation and issuance of restricted stock	'	'	2,260	'
Balances	-398,818	'	-398,818	'
Noncontrolling Interest	'	'	'	'
Increase (Decrease) in Equity	'	'	'	'
Balances	'	'	-51,468	'
Contributions from noncontrolling investors	'	'	97	'
Distributions to noncontrolling investors	'	'	-705	'
Net income (loss)	'	'	-14,359	'
Balances	-66,435	'	-66,435	'
Redeemable Noncontrolling Interest	'	'	'	'
Increase (Decrease) in Equity	'	'	'	'
Balances	'	'	116,514	'
Contributions from noncontrolling investors	'	'	9,826	'
Balances	$126,340	'	$126,340	'

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Futures

Futures

Futures

Futures

Futures

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Commodity Contract

Interest Rate Swap

Interest Rate Swap

Foreign Exchange Forward

Foreign Exchange Forward

Hedged Items Firm Commitment

Hedged Items Firm Commitment

Hedged Items Firm Commitment

Hedged Items Firm Commitment

Hedged Items Inventory

Hedged Items Inventory

Hedged Items Inventory

Hedged Items Inventory

Aluminum

Aluminum

Copper

Copper

Silver

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

Futures

derivative

derivative

derivative

derivative

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Long

Short

Long

Short

Short

Other Current Assets

Other Current Assets

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Designated as Hedging Instrument

Not Designated as Hedging Instrument

Not Designated as Hedging Instrument

Not Designated as Hedging Instrument

Not Designated as Hedging Instrument

Not Designated as Hedging Instrument

Not Designated as Hedging Instrument

Cost of Sales

Cost of Sales

Cost of Sales

Cost of Sales

Cost of Sales

Cost of Sales

Cost of Sales

Cost of Sales

MT

MT

MT

MT

lb

Cost of Sales

Cost of Sales

Cost of Sales

Cost of Sales

Other Current Assets

Other Current Assets

Cost of Sales

Cost of Sales

Cost of Sales

Cost of Sales

Other Current Assets

Other Current Assets

Commodity contract commitments

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of derivative instruments

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0

0

0

0

'

'

'

'

'

'

'

'

Commodity contract (in MT/Lbs)

'

'

'

'

3,300

3,975

6,226

18,296

343

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair values of derivative instruments, balance sheet

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Commodity futures, asset derivatives (in dollars)

'

'

'

'

'

'

'

'

'

$5,130,000

$1,010,000

'

'

'

'

'

'

'

'

'

'

$3,373,000

$658,000

'

'

'

'

$1,757,000

$352,000

'

'

'

'

'

'

'

'

'

'

'

'

Commodity futures, liability derivatives (in dollars)

'

'

'

'

'

'

'

'

'

1,225,000

4,487,000

'

'

'

'

'

'

'

'

'

'

528,000

1,886,000

'

'

'

'

697,000

2,601,000

'

'

'

'

'

'

'

'

'

'

'

'

Fair value of derivatives including required margin deposits

'

'

'

'

'

'

'

'

'

'

'

7,000,000

3,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gains or losses on derivative instruments, statement of income

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount of gain (loss) recognized in income on derivatives

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,371,000

381,000

3,356,000

7,773,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount of gain (loss) recognized in income on related hedged items

-3,379,000

-1,372,000

-2,690,000

-7,581,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

784,000

-1,736,000

1,115,000

877,000

-4,163,000

364,000

-3,805,000

-8,458,000

Amount of gain recognized in income on derivatives

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,672,000

-2,836,000

8,598,000

3,793,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ineffectiveness - amount of gain (loss) recognized in income on related hedged items

'

'

'

'

'

'

'

'

'

'

'

'

'

-229,000

-312,000

227,000

-199,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Gain (loss) excluded from hedge effectiveness testing

'

'

'

'

'

'

'

'

'

'

'

'

'

$1,200,000

($678,000)

$439,000

$392,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Commodity Contract | Futures	'	'
Assets and liabilities subject to fair value measurements	'	'
Commodity futures - financial assets	$5,130,000	$1,010,000
Commodity futures - financial liabilities	1,225,000	4,487,000
Recurring | Level 2	'	'
Assets and liabilities subject to fair value measurements	'	'
Fair value of long-term debt, including current maturities	3,100,000,000	2,300,000,000
Carrying amount of long-term debt, including current maturities	3,100,000,000	2,100,000,000
Recurring | Level 2 | Commodity Contract | Futures	'	'
Assets and liabilities subject to fair value measurements	'	'
Commodity futures - financial assets	5,130,000	1,010,000
Commodity futures - financial liabilities	1,225,000	4,487,000
Recurring | Total | Commodity Contract | Futures	'	'
Assets and liabilities subject to fair value measurements	'	'
Commodity futures - financial assets	5,130,000	1,010,000
Commodity futures - financial liabilities	$1,225,000	$4,487,000

Commitments_and_Contingencies_

Commitments and Contingencies (Details)	Sep. 30, 2014
	complaint
Commitments and Contingencies	'
Number of the complaints not brought on behalf of steel product purchasers	1

Segment_Information_Details

Segment Information (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Jun. 15, 2014

Jun. 12, 2014

segment

U.S.

U.S.

U.S.

U.S.

Non-U.S.

Non-U.S.

Non-U.S.

Non-U.S.

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Steel Fabrication Operations

Steel Fabrication Operations

Steel Fabrication Operations

Steel Fabrication Operations

Other

Other

Other

Other

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Operating Segment

Eliminations

Eliminations

Eliminations

Eliminations

Eliminations

Eliminations

Eliminations

Eliminations

5.125% convertible senior notes, due 2014

5.125% convertible senior notes, due 2014

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Steel Operations

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Metals Recycling/Ferrous Resources

Steel Fabrication Operations

Steel Fabrication Operations

Steel Fabrication Operations

Steel Fabrication Operations

Steel Fabrication Operations

Steel Fabrication Operations

Steel Fabrication Operations

Steel Fabrication Operations

Steel Fabrication Operations

Steel Fabrication Operations

Steel Fabrication Operations

Steel Fabrication Operations

Other

Other

Other

Other

Other

Other

Other

Other

Other

Other

Other

Other

Other

Other

Other

Other

Other segments

Other segments

Other segments

Other segments

Other segments

Other segments

Other segments

Other segments

U.S.

U.S.

U.S.

U.S.

Non-U.S.

Non-U.S.

Non-U.S.

Non-U.S.

Other segments

Other segments

Other segments

Other segments

U.S.

U.S.

U.S.

U.S.

Non-U.S.

Non-U.S.

Non-U.S.

Non-U.S.

Other segments

Other segments

Other segments

Other segments

U.S.

U.S.

U.S.

U.S.

Other segments

Other segments

Other segments

Other segments

U.S.

U.S.

U.S.

U.S.

Non-U.S.

Non-U.S.

Non-U.S.

Non-U.S.

Segment Information

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of reporting segments

'

'

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stated interest rate (as a percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5.13%

5.13%

Total net sales

$2,339,016

$1,911,738

$6,238,859

$5,508,774

'

$2,224,545

$1,803,540

$5,900,728

$5,187,404

$114,471

$108,198

$338,131

$321,370

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$2,339,016

$1,911,738

$6,238,859

$5,508,774

$1,526,532

$1,216,966

$4,022,768

$3,483,239

$75,320

$54,537

$188,854

$168,482

$1,400,370

$1,102,048

$3,675,696

$3,152,111

$50,842

$60,381

$158,218

$162,646

$998,487

$918,494

$2,867,022

$2,677,144

$326,090

$313,113

$973,635

$865,143

$609,098

$557,765

$1,714,440

$1,653,975

$63,299

$47,616

$178,947

$158,026

$190,036

$119,268

$440,749

$317,802

$43

$134

$43

$1,276

$189,993

$119,134

$440,706

$316,526

$33,754

$32,712

$93,174

$85,688

$8,340

$7,918

$22,322

$20,198

$25,084

$24,593

$69,886

$64,792

$330

$201

$966

$698

($409,793)

($375,702)

($1,184,854)

($1,055,099)

($409,793)

($375,702)

($1,184,854)

($1,055,099)

'

'

Operating income (loss)

188,643

113,273

401,480

278,703

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

200,116

146,564

461,708

351,410

'

'

'

'

'

'

'

'

'

'

'

'

-5,330

-17,135

-26,902

-34,210

'

'

'

'

'

'

'

'

'

'

'

'

19,474

3,265

30,190

7,125

'

'

'

'

'

'

'

'

-26,733

-17,274

-67,437

-48,147

'

'

'

'

'

'

'

'

'

'

'

'

1,116

-2,147

3,921

2,525

'

'

'

'

'

'

Income (loss) before income taxes

134,667

84,155

289,270

185,783

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

184,589

133,041

419,181

309,780

'

'

'

'

'

'

'

'

'

'

'

'

-11,724

-24,567

-47,054

-56,860

'

'

'

'

'

'

'

'

'

'

'

'

17,877

1,751

25,628

2,475

'

'

'

'

'

'

'

'

-57,191

-23,922

-112,406

-72,136

'

'

'

'

'

'

'

'

'

'

'

'

1,116

-2,148

3,921

2,524

'

'

'

'

'

'

Depreciation and amortization

65,957

58,202

181,966

172,089

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

32,998

26,815

89,244

79,698

'

'

'

'

'

'

'

'

'

'

'

'

28,775

27,713

81,266

81,553

'

'

'

'

'

'

'

'

'

'

'

'

2,974

2,219

7,597

6,455

'

'

'

'

'

'

'

'

1,262

1,506

4,013

4,536

'

'

'

'

'

'

'

'

'

'

'

'

-52

-51

-154

-153

'

'

'

'

'

'

Capital expenditures

24,531

52,162

82,906

146,744

'

'

'

'

'

'

'

'

'

12,195

33,985

47,133

93,244

11,599

17,385

33,762

49,999

477

297

1,324

2,000

260

495

687

1,501

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Assets

7,578,283

5,874,305

7,578,283

5,874,305

5,933,006

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,553,924

2,581,798

4,553,924

2,581,798

'

'

'

'

'

'

'

'

'

'

'

'

2,531,821

2,530,979

2,531,821

2,530,979

'

'

'

'

'

'

'

'

'

'

'

'

315,381

272,786

315,381

272,786

'

'

'

'

'

'

'

'

427,654

699,244

427,654

699,244

'

'

'

'

'

'

'

'

'

'

'

'

-250,497

-210,502

-250,497

-210,502

'

'

'

'

'

'

Liabilities

$4,540,294

$3,316,517

$4,540,294

$3,316,517

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$821,796

$533,966

$821,796

$533,966

'

'

'

'

'

'

'

'

'

'

'

'

$651,128

$593,674

$651,128

$593,674

'

'

'

'

'

'

'

'

'

'

'

'

$34,386

$22,908

$34,386

$22,908

'

'

'

'

'

'

'

'

$3,273,198

$2,366,273

$3,273,198

$2,366,273

'

'

'

'

'

'

'

'

'

'

'

'

($240,214)

($200,304)

($240,214)

($200,304)

'

'

'

'

'

'

Segment_Information_Details_2

Segment Information (Details 2) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Operating income (loss)	'	'	'	'	'	'	'	'
Corporate SG & A	($80,240,000)	($67,553,000)	($223,745,000)	($198,171,000)	'	'	'	'
Profit sharing	-12,865,000	-8,469,000	-28,729,000	-19,891,000	'	'	'	'
Operating income	188,643,000	113,273,000	401,480,000	278,703,000	'	'	'	'
Assets	'	'	'	'	'	'	'	'
Cash and equivalents	159,591,000	370,056,000	159,591,000	370,056,000	357,490,000	395,156,000	243,753,000	375,917,000
Accounts receivable	1,013,503,000	'	1,013,503,000	'	'	664,208,000	'	'
Inventories	1,664,212,000	'	1,664,212,000	'	'	1,314,747,000	'	'
Deferred income taxes	18,402,000	'	18,402,000	'	'	17,964,000	'	'
Property, plant and equipment, net	3,420,654,000	'	3,420,654,000	'	'	2,226,134,000	'	'
Other	94,047,000	'	94,047,000	'	'	115,083,000	'	'
Total assets	7,578,283,000	5,874,305,000	7,578,283,000	5,874,305,000	'	5,933,006,000	'	'
Liabilities	'	'	'	'	'	'	'	'
Accounts payable	640,121,000	'	640,121,000	'	'	414,932,000	'	'
Income taxes payable	26,949,000	'	26,949,000	'	'	4,023,000	'	'
Accrued interest	21,277,000	'	21,277,000	'	'	31,363,000	'	'
Deferred income taxes	543,838,000	'	543,838,000	'	'	556,038,000	'	'
Liabilities	4,540,294,000	3,316,517,000	4,540,294,000	3,316,517,000	'	'	'	'
Operating Segment | Other	'	'	'	'	'	'	'	'
Operating income (loss)	'	'	'	'	'	'	'	'
Corporate SG & A	-12,400,000	-9,200,000	-31,700,000	-26,300,000	'	'	'	'
Company-wide equity- based compensation	-5,100,000	-2,100,000	-14,400,000	-7,300,000	'	'	'	'
Profit sharing	-11,600,000	-7,400,000	-25,200,000	-16,500,000	'	'	'	'
Other, net	2,400,000	1,400,000	3,900,000	2,000,000	'	'	'	'
Operating income	-26,733,000	-17,274,000	-67,437,000	-48,147,000	'	'	'	'
Assets	'	'	'	'	'	'	'	'
Cash and equivalents	80,300,000	325,800,000	80,300,000	325,800,000	'	'	'	'
Accounts receivable	12,800,000	13,400,000	12,800,000	13,400,000	'	'	'	'
Inventories	15,200,000	14,000,000	15,200,000	14,000,000	'	'	'	'
Deferred income taxes	18,300,000	25,200,000	18,300,000	25,200,000	'	'	'	'
Property, plant and equipment, net	70,200,000	72,900,000	70,200,000	72,900,000	'	'	'	'
Debt issuance costs, net	39,600,000	27,700,000	39,600,000	27,700,000	'	'	'	'
Intra-company debt	160,200,000	153,600,000	160,200,000	153,600,000	'	'	'	'
Other	31,100,000	66,600,000	31,100,000	66,600,000	'	'	'	'
Total assets	427,654,000	699,244,000	427,654,000	699,244,000	'	'	'	'
Liabilities	'	'	'	'	'	'	'	'
Accounts payable	76,900,000	43,100,000	76,900,000	43,100,000	'	'	'	'
Income taxes payable	26,900,000	7,700,000	26,900,000	7,700,000	'	'	'	'
Accrued interest	21,100,000	22,900,000	21,100,000	22,900,000	'	'	'	'
Accrued profit sharing	25,200,000	19,500,000	25,200,000	19,500,000	'	'	'	'
Debt	2,990,200,000	2,041,800,000	2,990,200,000	2,041,800,000	'	'	'	'
Deferred income taxes	97,400,000	204,600,000	97,400,000	204,600,000	'	'	'	'
Other	35,500,000	26,700,000	35,500,000	26,700,000	'	'	'	'
Liabilities	$3,273,198,000	$2,366,273,000	$3,273,198,000	$2,366,273,000	'	'	'	'

Segment_Information_Details_3

Segment Information (Details 3) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Operating income (loss)	'	'	'	'	'
Gross profit increase (decrease) from intra-company sales	$288,512,000	$197,192,000	$674,587,000	$521,148,000	'
Assets elimination	'	'	'	'	'
Elimination of intra-company receivables	1,058,668,000	'	1,058,668,000	'	720,600,000
Other	94,047,000	'	94,047,000	'	115,083,000
Total assets	7,578,283,000	5,874,305,000	7,578,283,000	5,874,305,000	5,933,006,000
Liabilities elimination	'	'	'	'	'
Elimination of intra-company payables	640,121,000	'	640,121,000	'	414,932,000
Liabilities	4,540,294,000	3,316,517,000	4,540,294,000	3,316,517,000	'
Eliminations	'	'	'	'	'
Operating income (loss)	'	'	'	'	'
Gross profit increase (decrease) from intra-company sales	1,100,000	-2,100,000	3,900,000	2,500,000	'
Assets elimination	'	'	'	'	'
Elimination of intra-company receivables	-80,700,000	-46,900,000	-80,700,000	-46,900,000	'
Elimination of intra-company debt	-160,200,000	-153,600,000	-160,200,000	-153,600,000	'
Other	-9,600,000	-10,000,000	-9,600,000	-10,000,000	'
Total assets	-250,497,000	-210,502,000	-250,497,000	-210,502,000	'
Liabilities elimination	'	'	'	'	'
Elimination of intra-company payables	-81,200,000	-47,300,000	-81,200,000	-47,300,000	'
Elimination of intra-company debt	-160,200,000	-153,600,000	-160,200,000	-153,600,000	'
Other	1,200,000	600,000	1,200,000	600,000	'
Liabilities	-240,214,000	-200,304,000	-240,214,000	-200,304,000	'
Severstal Columbus LLC	'	'	'	'	'
Acquisition	'	'	'	'	'
Acquisition and related costs	$25,000,000	'	$25,000,000	'	'

Condensed_Consolidating_Inform2

Condensed Consolidating Information (Details) (USD $)	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Condensed Consolidating Balance Sheets	'	'	'	'	'	'
Ownership interest in subsidiaries (as a percent)	100.00%	'	'	'	'	'
Cash and equivalents	$159,591	$357,490	$395,156	$370,056	$243,753	$375,917
Accounts receivable, net	1,058,668	'	720,600	'	'	'
Inventories	1,664,212	'	1,314,747	'	'	'
Other current assets	47,665	'	43,131	'	'	'
Total current assets	2,930,136	'	2,473,634	'	'	'
Property, plant and equipment, net	3,420,654	'	2,226,134	'	'	'
Intangible assets, net	406,318	'	386,159	'	'	'
Goodwill	727,128	'	731,996	'	'	'
Other assets, including investments in subs	94,047	'	115,083	'	'	'
Total assets	7,578,283	'	5,933,006	5,874,305	'	'
Accounts payable	640,121	'	414,932	'	'	'
Accrued expenses	269,561	'	218,702	'	'	'
Current maturities of long-term debt	131,858	'	341,544	'	'	'
Total current liabilities	1,041,540	'	975,178	'	'	'
Long-term debt	2,929,994	'	1,766,045	'	'	'
Other liabilities	568,760	'	579,414	'	'	'
Redeemable noncontrolling interests	126,340	'	116,514	'	'	'
Common stock	649	'	645	'	'	'
Treasury stock	-398,818	'	-718,529	'	'	'
Additional paid-in capital	1,075,593	'	1,085,694	'	'	'
Retained earnings (deficit)	2,300,660	'	2,179,513	'	'	'
Total Steel Dynamics, Inc. equity	2,978,084	'	2,547,323	'	'	'
Noncontrolling interests	-66,435	'	-51,468	'	'	'
Total equity	2,911,649	'	2,495,855	'	'	'
Total liabilities and equity	7,578,283	'	5,933,006	'	'	'
Reportable legal entity | Parent	'	'	'	'	'	'
Condensed Consolidating Balance Sheets	'	'	'	'	'	'
Cash and equivalents	74,925	'	320,866	322,212	'	322,707
Accounts receivable, net	325,667	'	309,691	'	'	'
Inventories	695,441	'	673,763	'	'	'
Other current assets	52,092	'	50,228	'	'	'
Total current assets	1,148,125	'	1,354,548	'	'	'
Property, plant and equipment, net	1,020,150	'	1,046,093	'	'	'
Other assets, including investments in subs	4,249,944	'	2,630,411	'	'	'
Total assets	6,418,219	'	5,031,052	'	'	'
Accounts payable	213,990	'	160,255	'	'	'
Accrued expenses	161,890	'	142,055	'	'	'
Current maturities of long-term debt	98,374	'	315,521	'	'	'
Total current liabilities	474,254	'	617,831	'	'	'
Long-term debt	2,894,071	'	1,725,433	'	'	'
Other liabilities	71,810	'	140,465	'	'	'
Common stock	649	'	645	'	'	'
Treasury stock	-398,818	'	-718,529	'	'	'
Additional paid-in capital	1,075,593	'	1,085,694	'	'	'
Retained earnings (deficit)	2,300,660	'	2,179,513	'	'	'
Total Steel Dynamics, Inc. equity	2,978,084	'	2,547,323	'	'	'
Total equity	2,978,084	'	2,547,323	'	'	'
Total liabilities and equity	6,418,219	'	5,031,052	'	'	'
Reportable legal entity | Guarantors	'	'	'	'	'	'
Condensed Consolidating Balance Sheets	'	'	'	'	'	'
Cash and equivalents	70,695	'	61,148	37,710	'	41,675
Accounts receivable, net	1,312,449	'	874,707	'	'	'
Inventories	856,685	'	557,640	'	'	'
Other current assets	7,761	'	8,399	'	'	'
Total current assets	2,247,590	'	1,501,894	'	'	'
Property, plant and equipment, net	1,846,279	'	619,617	'	'	'
Intangible assets, net	406,318	'	386,159	'	'	'
Goodwill	727,128	'	731,996	'	'	'
Other assets, including investments in subs	24,717	'	21,789	'	'	'
Total assets	5,252,032	'	3,261,455	'	'	'
Accounts payable	449,535	'	258,406	'	'	'
Accrued expenses	161,000	'	115,182	'	'	'
Current maturities of long-term debt	756	'	300	'	'	'
Total current liabilities	611,291	'	373,888	'	'	'
Long-term debt	624	'	'	'	'	'
Other liabilities	1,940,011	'	1,986,260	'	'	'
Common stock	1,727,859	'	33,896	'	'	'
Additional paid-in capital	117,737	'	117,737	'	'	'
Retained earnings (deficit)	854,510	'	749,674	'	'	'
Total Steel Dynamics, Inc. equity	2,700,106	'	901,307	'	'	'
Total equity	2,700,106	'	901,307	'	'	'
Total liabilities and equity	5,252,032	'	3,261,455	'	'	'
Reportable legal entity | Combined Non-Guarantors	'	'	'	'	'	'
Condensed Consolidating Balance Sheets	'	'	'	'	'	'
Cash and equivalents	13,971	'	13,142	10,134	'	11,535
Accounts receivable, net	59,672	'	32,018	'	'	'
Inventories	115,089	'	91,199	'	'	'
Other current assets	6,289	'	3,259	'	'	'
Total current assets	195,021	'	139,618	'	'	'
Property, plant and equipment, net	556,490	'	562,843	'	'	'
Other assets, including investments in subs	6,870	'	8,092	'	'	'
Total assets	758,381	'	710,553	'	'	'
Accounts payable	111,505	'	60,987	'	'	'
Accrued expenses	11,636	'	10,694	'	'	'
Current maturities of long-term debt	72,368	'	52,163	'	'	'
Total current liabilities	195,509	'	123,844	'	'	'
Long-term debt	184,044	'	204,385	'	'	'
Other liabilities	36,691	'	34,895	'	'	'
Redeemable noncontrolling interests	126,340	'	116,514	'	'	'
Common stock	18,121	'	18,121	'	'	'
Additional paid-in capital	601,282	'	552,946	'	'	'
Retained earnings (deficit)	-337,171	'	-288,684	'	'	'
Total Steel Dynamics, Inc. equity	282,232	'	282,383	'	'	'
Noncontrolling interests	-66,435	'	-51,468	'	'	'
Total equity	215,797	'	230,915	'	'	'
Total liabilities and equity	758,381	'	710,553	'	'	'
Consolidating Adjustments	'	'	'	'	'	'
Condensed Consolidating Balance Sheets	'	'	'	'	'	'
Accounts receivable, net	-639,120	'	-495,816	'	'	'
Inventories	-3,003	'	-7,855	'	'	'
Other current assets	-18,477	'	-18,755	'	'	'
Total current assets	-660,600	'	-522,426	'	'	'
Property, plant and equipment, net	-2,265	'	-2,419	'	'	'
Other assets, including investments in subs	-4,187,484	'	-2,545,209	'	'	'
Total assets	-4,850,349	'	-3,070,054	'	'	'
Accounts payable	-134,909	'	-64,716	'	'	'
Accrued expenses	-64,965	'	-49,229	'	'	'
Current maturities of long-term debt	-39,640	'	-26,440	'	'	'
Total current liabilities	-239,514	'	-140,385	'	'	'
Long-term debt	-148,745	'	-163,773	'	'	'
Other liabilities	-1,479,752	'	-1,582,206	'	'	'
Common stock	-1,745,980	'	-52,017	'	'	'
Additional paid-in capital	-719,019	'	-670,683	'	'	'
Retained earnings (deficit)	-517,339	'	-460,990	'	'	'
Total Steel Dynamics, Inc. equity	-2,982,338	'	-1,183,690	'	'	'
Total equity	-2,982,338	'	-1,183,690	'	'	'
Total liabilities and equity	($4,850,349)	'	($3,070,054)	'	'	'

Condensed_Consolidating_Inform3

Condensed Consolidating Information (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Condensed Consolidating Statements of Operations	'	'	'	'
Net sales	$2,339,016	$1,911,738	$6,238,859	$5,508,774
Costs of goods sold	2,050,504	1,714,546	5,564,272	4,987,626
Gross profit	288,512	197,192	674,587	521,148
Selling, general and administrative	99,869	83,919	273,107	242,445
Operating income	188,643	113,273	401,480	278,703
Interest expense, net of capitalized interest	31,904	30,970	92,523	97,064
Other (income) expense, net	22,072	-1,852	19,687	-4,144
Income before income taxes	134,667	84,155	289,270	185,783
Income taxes (benefit)	47,010	33,065	101,574	70,168
Net income	87,657	51,090	187,696	115,615
Net loss attributable to noncontrolling interests	3,516	6,396	14,359	19,044
Net income attributable to Steel Dynamics, Inc.	91,173	57,486	202,055	134,659
Reportable legal entity | Parent	'	'	'	'
Condensed Consolidating Statements of Operations	'	'	'	'
Net sales	1,044,207	902,280	2,915,339	2,566,286
Costs of goods sold	856,372	760,589	2,477,791	2,220,737
Gross profit	187,835	141,691	437,548	345,549
Selling, general and administrative	40,932	30,073	105,185	83,675
Operating income	146,903	111,618	332,363	261,874
Interest expense, net of capitalized interest	18,965	19,733	57,357	61,927
Other (income) expense, net	22,548	-2,423	20,016	-4,776
Income before income taxes	105,390	94,308	254,990	204,723
Income taxes (benefit)	30,605	24,930	64,480	41,945
Net income	74,785	69,378	190,510	162,778
Equity in net loss of subsidiaries	16,388	-11,892	11,545	-28,119
Net income attributable to Steel Dynamics, Inc.	91,173	57,486	202,055	134,659
Reportable legal entity | Guarantors	'	'	'	'
Condensed Consolidating Statements of Operations	'	'	'	'
Net sales	2,609,731	2,136,327	7,035,579	6,150,327
Costs of goods sold	2,469,396	2,025,470	6,668,153	5,840,025
Gross profit	140,335	110,857	367,426	310,302
Selling, general and administrative	59,878	55,348	170,578	164,104
Operating income	80,457	55,509	196,848	146,198
Interest expense, net of capitalized interest	12,238	10,561	33,093	33,351
Other (income) expense, net	-202	631	147	645
Income before income taxes	68,421	44,317	163,608	112,202
Income taxes (benefit)	24,754	16,579	58,772	41,712
Net income	43,667	27,738	104,836	70,490
Net income attributable to Steel Dynamics, Inc.	43,667	27,738	104,836	70,490
Reportable legal entity | Combined Non-Guarantors	'	'	'	'
Condensed Consolidating Statements of Operations	'	'	'	'
Net sales	150,551	91,198	377,639	245,607
Costs of goods sold	162,094	114,408	427,029	318,163
Gross profit	-11,543	-23,210	-49,390	-72,556
Selling, general and administrative	3,601	2,622	10,415	7,433
Operating income	-15,144	-25,832	-59,805	-79,989
Interest expense, net of capitalized interest	1,958	1,915	5,824	5,405
Other (income) expense, net	-1,530	-1,301	-4,226	-3,633
Income before income taxes	-15,572	-26,446	-61,403	-81,761
Income taxes (benefit)	-561	2,004	949	4,085
Net income	-15,011	-28,450	-62,352	-85,846
Net loss attributable to noncontrolling interests	3,516	6,396	14,359	19,044
Net income attributable to Steel Dynamics, Inc.	-11,495	-22,054	-47,993	-66,802
Consolidating Adjustments	'	'	'	'
Condensed Consolidating Statements of Operations	'	'	'	'
Net sales	-1,465,473	-1,218,067	-4,089,698	-3,453,446
Costs of goods sold	-1,437,358	-1,185,921	-4,008,701	-3,391,299
Gross profit	-28,115	-32,146	-80,997	-62,147
Selling, general and administrative	-4,542	-4,124	-13,071	-12,767
Operating income	-23,573	-28,022	-67,926	-49,380
Interest expense, net of capitalized interest	-1,257	-1,239	-3,751	-3,619
Other (income) expense, net	1,256	1,241	3,750	3,620
Income before income taxes	-23,572	-28,024	-67,925	-49,381
Income taxes (benefit)	-7,788	-10,448	-22,627	-17,574
Net income	-15,784	-17,576	-45,298	-31,807
Equity in net loss of subsidiaries	-16,388	11,892	-11,545	28,119
Net income attributable to Steel Dynamics, Inc.	($32,172)	($5,684)	($56,843)	($3,688)

Condensed_Consolidating_Inform4

Condensed Consolidating Information (Details 3) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Condensed Consolidating Statements of Cash Flows	'	'	'	'
Net cash provided by (used in) operating activities	$249,224	$183,266	$297,991	$245,691
Net cash provided by (used in) investing activities	-1,669,035	-51,318	-1,696,212	-111,103
Net cash provided by (used in) financing activities	1,221,912	-5,645	1,162,656	-140,449
Increase (decrease) in cash and equivalents	-197,899	126,303	-235,565	-5,861
Cash and equivalents at beginning of period	357,490	243,753	395,156	375,917
Cash and equivalents at end of period	159,591	370,056	159,591	370,056
Reportable legal entity | Parent	'	'	'	'
Condensed Consolidating Statements of Cash Flows	'	'	'	'
Net cash provided by (used in) operating activities	'	'	258,952	126,404
Net cash provided by (used in) investing activities	'	'	-1,692,967	-115,979
Net cash provided by (used in) financing activities	'	'	1,188,074	-10,920
Increase (decrease) in cash and equivalents	'	'	-245,941	-495
Cash and equivalents at beginning of period	'	'	320,866	322,707
Cash and equivalents at end of period	74,925	322,212	74,925	322,212
Reportable legal entity | Guarantors	'	'	'	'
Condensed Consolidating Statements of Cash Flows	'	'	'	'
Net cash provided by (used in) operating activities	'	'	80,298	164,383
Net cash provided by (used in) investing activities	'	'	15,023	-28,654
Net cash provided by (used in) financing activities	'	'	-85,774	-139,694
Increase (decrease) in cash and equivalents	'	'	9,547	-3,965
Cash and equivalents at beginning of period	'	'	61,148	41,675
Cash and equivalents at end of period	70,695	37,710	70,695	37,710
Reportable legal entity | Combined Non-Guarantors	'	'	'	'
Condensed Consolidating Statements of Cash Flows	'	'	'	'
Net cash provided by (used in) operating activities	'	'	-41,245	-56,636
Net cash provided by (used in) investing activities	'	'	-16,740	-20,230
Net cash provided by (used in) financing activities	'	'	58,814	75,465
Increase (decrease) in cash and equivalents	'	'	829	-1,401
Cash and equivalents at beginning of period	'	'	13,142	11,535
Cash and equivalents at end of period	13,971	10,134	13,971	10,134
Consolidating Adjustments	'	'	'	'
Condensed Consolidating Statements of Cash Flows	'	'	'	'
Net cash provided by (used in) operating activities	'	'	-14	11,540
Net cash provided by (used in) investing activities	'	'	-1,528	53,760
Net cash provided by (used in) financing activities	'	'	$1,542	($65,300)