Note 1. Description of the Business and Summary of 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. In the third quarter 2015, the company changed its reportable segments, consistent with how it currently manages the business, representing three reporting segments: steel operations, metals recycling operations, and steel fabrication operations. Segment information provided within this Form 10-K, including that within Note 13: Segment Information, has been adjusted for all prior periods consistent with the current reportable segment presentation. Approximately 9% of the company's workforce is represented by collective bargaining agreements, and one of these agreements affecting 117 employees at one location expires during 2016.

Steel Operations Segment

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, Steel of West Virginia, and with the third quarter 2015 segment changes, Iron Dynamics (IDI), a liquid pig iron (scrap substitute) production facility that supplies solely the Butler Flat Roll Division. These operations include electric arc furnace steel mills, producing steel from ferrous scrap and scrap substitutes, utilizing continuous casting, automated rolling mills, and ten downstream coating lines. Steel operations accounted for 69%, 63%, and 61% of the company's consolidated net sales during 2015, 2014, and 2013, respectively.

Butler and Columbus Flat Roll Divisions sell a broad range of sheet steel products, such as hot roll, cold roll and coated steel products, including a wide variety of specialty products, such as light gauge hot roll and galvanized. Butler Flat Roll Division sells other products such as Galvalume® and painted products, while Columbus Flat Roll Division sells other products used to produce non-energy line pipe, and is currently in the construction phase of a $100 million expansion to add painted and Galvalume® capacity. The Techs is comprised of three galvanizing lines which sell specialized galvanized sheet steels used in non-automotive applications. The Structural and Rail Division sells structural steel beams and pilings to the construction market, as well as standard-grade and premium rail to the railroad industry. The Engineered Bar Products Division primarily sells engineered, special-bar-quality and merchant-bar-quality rounds, round-cornered squares, and smaller-diameter round engineered bars. The Roanoke Bar primarily sells merchant steel products, including angles, merchant rounds, flats and channels, and reinforcing bar. Steel of West Virginia primarily sells beams, channels and specialty steel sections. The company's steel operations sell directly to end users and service centers. These products are used in numerous industry sectors, including the automotive, construction, manufacturing, transportation, heavy and agriculture equipment, and pipe and tube (including OCTG) markets.

Metals Recycling Operations Segment

Metals recycling operations consist solely of OmniSource Corporation (OmniSource), the company's metals recycling and processing locations, and ferrous scrap procurement operations. Metals recycling operations accounted for 19%, 25 and 31% of the company's consolidated net sales during 2015, 2014, and 2013, respectively.

Steel Fabrication Operations Segment

Steel fabrication operations include the company's eight 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 deck used within the non-residential construction industry. Steel fabrication operations accounted for 9%, 7%, and 6% of the company's consolidated net sales during 2015, 2014, and 2013, respectively.

Other

The "Other" category consists of subsidiary operations that are below the quantitative thresholds required for reportable segments and primarily consist of our Minnesota ironmaking operations and several smaller joint ventures. Also included in "Other" are certain unallocated corporate accounts, such as the company's senior secured credit facility, senior notes, certain other investments and certain profit sharing expenses.

Our Minnesota ironmaking operations consists of Mesabi Nugget, (owned 82% by us); our iron concentrating and potential future iron mining operations, Mesabi Mining; and our iron tailings operation, Mining Resources (owned 81% by us). See discussion of 2014 Minnesota ironmaking operations impairment later in Note 1 under "Impairment of Long-Lived Tangible and Definite-Lived Intangible Assets." The Minnesota ironmaking operations were indefinitely idled in May 2015.

Three years subsequent to Mesabi Nugget achieving certain performance measures (which as of December 31, 2015, had not been met), the noncontrolling investor may elect to require the company to purchase at par value all (but not less than all) of the units it owns at the time of such election. At any time after that same date, the company may elect to purchase at par value all of the units owned by the noncontrolling investor. The $111.2 million par value owned by the noncontrolling investor at December 31, 2015, and 2014 has been reported as redeemable noncontrolling interest in the consolidated balance sheets.

On the fifth anniversary of the effective date of the formation of Mining Resources (2016), the noncontrolling investor has a non-transferable, non-assignable right to require the company to purchase at fair value all (but not less than all) of the units it owns at that time. The $15.1 million value owned by the noncontrolling investor at December 31, 2015, and 2014, has been reported as redeemable noncontrolling interest in the consolidated balance sheet.

Summary of 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.

Revenue Recognition and Allowances for Doubtful Accounts

Except for the steel fabrication operations, the company recognizes revenues from sales and the allowance for estimated returns and claims from these sales at the time the title of the product transfers, upon shipment. Provision is made for estimated product returns and customer claims based on historical experience. If the historical data used in the estimates does not reflect future returns and claims trends, additional provision may be necessary. The company's steel fabrication operations recognizes revenues from construction contracts utilizing a percentage of completion methodology based on steel tons used on completed units to date as a percentage of estimated total steel tons required for each contract. The allowance for doubtful accounts for all operating segments is based on the company's best estimate of probable credit losses, along with historical experience.

Cash and Equivalents

Cash and equivalents include all highly liquid investments with a maturity of three months or less at the date of acquisition. Restricted cash is primarily funds held in escrow as required by various insurance and government organizations.

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 other inventory. Inventory consisted of the following at December 31 (in thousands):

	2015		2014
Raw materials	$	419,608	$	764,883
Supplies		396,349		374,599
Work in progress		90,486		128,882
Finished goods		242,947		350,055

	$	1,149,390	$	1,618,419

Investments

The company has investments in certain joint ventures and closely-held companies in which ownership varies between 49% and 50%. For these investments where the company does not have effective control, the company accounts for the investment using the equity method of accounting. Investments in companies in which the company does not exercise control and its ownership is less than 20% are carried at cost. These investments are reflected in other long-term assets on the company's balance sheet in an amount of $6.4 million and $18.4 million at December 31, 2015, and 2014, respectively. The company's equity in the income (losses) of investments accounted for using the equity method of accounting are recorded in other (income) expenses, net, in our consolidated statements of operations.

Property, Plant and Equipment

Property, plant and equipment are stated at cost, which includes capitalized interest on construction-in-progress amounts, and is reduced by proceeds received from certain state and local government grants and other capital cost reimbursements. The company assigns each fixed asset a useful life ranging from 3 to 20 years for plant, machinery and equipment and 10 to 40 years for buildings and improvements. Repairs and maintenance are expensed as incurred. Depreciation is provided utilizing the straight-line depreciation methodology, or the units-of-production depreciation methodology for certain production related assets, based on units produced, subject to a minimum and maximum level. Depreciation expense was $263.2 million, $229.4 million, and $192.4 million for the years ended December 31, 2015, 2014, and 2013, respectively.

The company's property, plant and equipment at December 31 consisted of the following (in thousands):

	2015		2014
Land and improvements	$	328,739	$	334,583
Buildings and improvements		706,708		713,837
Plant, machinery and equipment		3,966,181		3,898,275
Construction in progress		76,074		63,344

		5,077,702		5,010,039
Less accumulated depreciation		2,126,492		1,886,133

Property, plant and equipment, net	$	2,951,210	$	3,123,906

Intangible Assets

The company's intangible assets, at December 31, consisted of the following (in thousands):

	2015		2014		Useful Life	Weighted Average Amortization Period
Customer and scrap generator relationships	$	420,400	$	419,400	10 to 25 years	19 years
Trade names		121,300		189,800	Indefinite	—
Trade name		3,200		3,200	12 years	12 years

		544,900		612,400		19 years
Less accumulated amortization		265,940		241,731

	$	278,960	$	370,669

Refer to "Impairment of Goodwill and Indefinite-Lived Intangible Assets" below in Note 1 for discussion regarding the 2015 impairment of OmniSource trade name. The company utilizes an accelerated amortization methodology for customer and scrap generator relationships in order to follow the pattern in which the economic benefits of the amounts are anticipated to be consumed. Definite-lived trade names are amortized using a straight line methodology. Amortization of intangible assets was $25.3 million, $26.4 million, and $30.5 million for the years ended December 31, 2015, 2014, and 2013, respectively. Estimated amortization expense, related to amortizable intangibles, for the years ending December 31 is as follows (in thousands):

2016	$	22,039
2017		19,257
2018		16,723
2019		15,184
2020		13,365
Thereafter		71,092

Total	$	157,660

Impairment of Long-Lived Tangible and Definite-Lived Intangible Assets

The company reviews long-lived assets for impairment whenever events or changes in circumstances indicate the carrying amount of such assets may not be fully recoverable. Impairment losses are recorded on long-lived assets used in operations when indicators of impairment are present and the undiscounted cash flows estimated to be generated by those assets are less than the assets' carrying amounts. The impairment loss is measured by comparing the fair value of the asset to its carrying amount. We consider various factors and determine whether an impairment test is necessary, including by way of examples, a significant and prolonged deterioration in operating results and/or projected cash flows, significant changes in the extent or manner in which an asset is used, technological advances with respect to assets which would potentially render them obsolete, our strategy and capital planning, and the economic climate in markets to be served.

A long-lived asset is classified as held for sale upon meeting specified criteria related to ability and intent to sell. An asset classified as held for sale is measured at the lower of its carrying amount or fair value less cost to sell. As of December 31, 2015, the company reported $8.6 million of assets held for sale within other current assets in our consolidated balance sheet. An impairment loss is recognized for any initial or subsequent write-down of the asset held for sale to its fair value less cost to sell. Upon the December 31, 2015, determination and classification of these assets as held for sale, the company recorded a $10.3 million asset impairment charge in the consolidated statement of operations for the year ended December 31, 2015. The company determined fair value using Level 3 inputs as provided for under ASC 820, consisting of information provided by brokers and other external sources along with management's own assumptions.

During the fourth quarter of 2014, the company's Minnesota ironmaking operations reached a steady operating state, indicating a consistency in the operations' production capability, processes and cost structure, including the ability to utilize certain lower-cost raw materials. Given this, the company undertook an assessment of the recoverability of the carrying value of its Minnesota ironmaking operations' fixed assets. With the company's outlook at the time regarding future operating costs and product pricing, the company concluded that the carrying value of these fixed assets was no longer fully recoverable, and the fixed assets were in fact impaired. This assessment resulted in a $260.0 million pretax non-cash impairment charge, including amounts attributable to noncontrolling interests of $46.5 million, which is reflected in "Other" in Note 13, Segment Information. The carrying values of the impaired assets were adjusted to their estimated fair values as determined primarily on the cost approach, as well as expected future discounted cash flows (an income approach), using Level 3 inputs as provided for under ASC 820. The Minnesota ironmaking operations were indefinitely idled in May 2015.

Goodwill

The company's goodwill is allocated to the following reporting units at December 31, (in thousands):

	2015		2014
OmniSource—Metals Recycling Operations Segment	$	109,039	$	456,727
Butler Flat Roll Division, Structural and Rail Division, and Engineered Bar Division—Metals Recycling Operations Segment		95,000		95,000
The Techs—Steel Operations Segment		142,783		142,783
Roanoke Bar Division—Steel Operations Segment		29,041		29,041
Columbus Flat Roll Division—Steel Operation Segment		19,682		19,682
New Millennium Building Systems—Steel Fabrication Operations Segment		1,925		1,925

	$	397,470	$	745,158

In 2015, a $341.3 million OmniSource goodwill impairment charge was recorded pursuant to the company's annual review for impairment of goodwill and indefinite-lived intangible assets, as discussed further under "Impairment of Goodwill and Indefinite-Lived Intangible Assets" below. Cumulative OmniSource goodwill impairment charges are $341.3 million at December 31, 2015.

OmniSource goodwill decreased $6.4 million in 2015, in recognition of the 2015 tax benefit related to the normal amortization of the component of OmniSource tax-deductible goodwill in excess of book goodwill.

Impairment of Goodwill and Indefinite-Lived Intangible Assets

At least once annually (as of October 1) or when indicators of impairment exist, the company performs an impairment test for goodwill and other indefinite-lived intangible assets. Goodwill is allocated to various reporting units, which are generally one level below the company's operating segments. The company utilizes a two-stepped approach to evaluate goodwill impairment. The first step of the test determines if there is potential goodwill impairment. In this step the company compares the fair value of the reporting unit to its carrying amount (which includes goodwill). The fair value of the reporting unit is determined by using an estimate of future cash flows utilizing a risk-adjusted discount rate to calculate the net present value of future cash flows (income approach), and by using a market approach based upon an analysis of valuation metrics of comparable peer companies, Level 3 inputs as provided for under ASC 820. If the fair value exceeds the carrying value, there is no impairment. If the carrying amount exceeds the fair value, the company performs the second step of the test, which measures the amount of impairment loss to be recorded. In the second step, the company compares the carrying amount of the goodwill to the implied fair value of the goodwill based on the net fair value of the recognized and unrecognized assets and liabilities of the reporting unit to which it is allocated. If the implied fair value is less than the carrying value, an impairment loss is recorded to the extent that the fair value of the goodwill is less than its carrying value.

At least once annually (as of October 1) or when indicators of impairment exist, the company tests indefinite-lived intangible assets for impairment through the comparison of the fair value of the specific intangible asset with its carrying amount. The fair value of the intangible asset is determined by using an estimate of future cash flows attributable to the asset and a risk-adjusted discount rate to compute a net present value of future cash flows (income approach). If the fair value is less than the carrying value, an impairment loss is recorded in an amount equal to the excess in carrying value.

During the company's 2015 annual goodwill and indefinite-lived intangible asset impairment analysis, we determined that the fair value of OmniSource was less than its carrying value, and upon the completion of the second step of the impairment analysis, that the goodwill and trade name indefinite-lived intangible assets were impaired. The decrease in OmniSource fair value from prior impairment analysis was due primarily to the reduction in expected future cash flows based on management's view of the weak shorter and longer-term global scrap commodity outlook. The OmniSource goodwill and trade name indefinite-lived intangible assets were written down to their respective fair values, resulting in non-cash asset impairment charges of $341.3 million and $68.5 million, respectively, that are reflected in asset impairment charges in the consolidated statement of operations for the year ended December 31, 2015, within the metals recycling operations.

Equity-Based Compensation

The company has several stock-based employee compensation plans which are more fully described in Note 6. Compensation expense for restricted stock units, deferred stock units, restricted stock, and performance awards is recorded over the vesting periods using the fair value as determined by the closing fair market value of the company's common stock on the grant date, and with respect to performance awards, an estimate of probability of award achievement during the performance period. Compensation expense for these stock-based employee compensation plans was $27.1 million, $22.8 million, and $15.2 million for the years ended December 31, 2015, 2014, and 2013, respectively.

Income Taxes

The company accounts for income taxes and the related accounts under the liability method. Deferred tax liabilities and assets are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted rates expected to be in effect during the year in which the basis differences reverse.

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 in 2014 and 2013, dilutive shares related to the company's convertible subordinated debt; and are excluded from the computation in periods in which they have an anti-dilutive effect. There were 1.5 million anti-dilutive common stock equivalents as of and for the year ended December 31, 2015. There were no anti-dilutive common share equivalents at or for the year ended December 31, 2014, and 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 the years ended December 31 (in thousands, except per share data):

	2015
	Net Loss (Numerator)			Shares (Denominator)		Per Share Amount
Basic earnings per share	$	(130,311	)		242,017	$	(0.54	)
Dilutive stock options, deferred stock units, and restricted stock units		—			—

Diluted earnings per share	$	(130,311	)		242,017	$	(0.54	)

	2014						2013
	Net Income (Numerator)		Shares (Denominator)		Per Share Amount		Net Income (Numerator)		Shares (Denominator)		Per Share Amount
Basic earnings per share	$	157,024		232,547	$	0.68	$	189,314		220,916	$	0.86
Dilutive stock options, deferred stock units, and restricted stock units		—		1,828				—		1,392
5.125% convertible senior notes		4,327		7,703				9,432		16,688

Diluted earnings per share	$	161,351		242,078	$	0.67	$	198,746		238,996	$	0.83

Concentration of Credit Risk

Financial instruments that potentially subject the company to significant concentrations of credit risk principally consist of temporary cash investments and accounts receivable. The company places its temporary cash investments with high credit quality financial institutions and companies, and limits the amount of credit exposure from any one entity. The company is exposed to credit risk in the event of nonpayment by customers. The company mitigates its exposure to credit risk, which it generally extends initially on an unsecured basis, by performing ongoing credit evaluations and taking further action if necessary, such as requiring letters of credit or other security interests to support the customer receivable. Management's estimation of the allowance for doubtful accounts is based upon known credit risks, historical loss experience and current economic conditions affecting the company's customers. Customer accounts receivable are charged off when all collection efforts have been exhausted and the amounts are deemed uncollectible. Heidtman Steel Products (Heidtman), a related party, accounted for 5% of the company's net accounts receivable at December 31, 2015, and 4% at December 31, 2014.

Derivative Financial Instruments

The company recognizes all derivatives as either assets or liabilities in the consolidated balance sheets and measures those instruments at fair value. Derivatives that are not designated as hedges must be adjusted to fair value through earnings. Changes in the fair value of derivatives that are designated as hedges, depending on the nature of the hedge, are recognized as either an offset against the change in fair value of the hedged balance sheet item in the case of fair value hedges or as other comprehensive income in the case of cash flow hedges, until the hedged item is recognized in earnings. The ineffective portion of a derivative's change in fair value is immediately recognized in earnings. The company offsets fair value amounts recognized for derivative instruments executed with the same counterparty under master netting agreements.

In the normal course of business, the company may have involvement with derivative financial instruments related to managing fluctuations in interest rates, foreign exchange rates, and forward contracts in various commodities. At the time of acquiring these financial instruments, the company designates and assigns these instruments as hedges of specific assets, liabilities or anticipated transactions. When hedged assets or liabilities are sold or extinguished, or the anticipated transaction being hedged is no longer expected to occur, the company recognizes the gain or loss on the designated hedged financial instrument.

The company routinely enters into forward contracts in various commodities, primarily nonferrous metals (specifically aluminum, copper, nickel and silver) in our metals recycling operations, to reduce exposure to commodity related price fluctuations. The company does not enter into these derivative financial instruments for speculative purposes.

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 core principle of ASC 606 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. Because the guidance in ASC 606 is principles-based, it can be applied to all contracts with customers regardless of industry-specific or transaction-specific fact patterns. Additionally, ASC 606 requires additional disclosures to help users of financial statements better understand the nature, amount, timing, and potential uncertainty of revenue that is recognized. This guidance is effective for annual and interim periods beginning after December 15, 2017, but can be early adopted for annual and interim periods ending after December 15, 2016. The company is currently evaluating the impact of the provisions of ASC 606, including the timing of adoption.

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 principal conditions or events are identified that raised substantial doubt about the entity's ability to continue as a going concern (before consideration of management's plans), as well as 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.

In July 2015, the FASB issued ASU 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory, which requires an entity to measure inventory at the lower of cost and net realizable value, rather than at the lower of cost or market. This new guidance is effective for interim and annual periods beginning after December 15, 2016, but can be early adopted. The company is currently evaluating the impact of this ASU's adoption.