Steel Dynamics (STLD) 10-K 28 Feb 25 2024 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2024	Feb. 24, 2025	Jun. 30, 2024
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2024
Document Transition Report	false
Securities Act File Number	0-21719
Entity Registrant Name	Steel Dynamics, Inc.
Entity Incorporation, State or Country Code	IN
Entity Tax Identification Number	35-1929476
Entity Address, Address Line One	7575 West Jefferson Blvd
Entity Address, City or Town	Fort Wayne
Entity Address, State or Province	IN
Entity Address, Postal Zip Code	46804
City Area Code	260
Local Phone Number	969-3500
Title of 12(b) Security	Common Stock voting, $0.0025 par value
Trading Symbol	STLD
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 14.8
Entity Common Stock, Shares Outstanding		150,163,986
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42
Auditor Location	Indianapolis, Indiana
Entity Central Index Key	0001022671
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Current assets
Cash and equivalents	$ 589,464	$ 1,400,887
Short-term investments	147,811	721,210
Inventories	3,113,733	2,894,632
Other current assets	163,131	162,790
Total current assets	5,431,338	6,787,826
Property, plant and equipment, net	8,117,988	6,734,218
Intangible assets, net	227,234	257,759
Goodwill	477,471	477,471
Other assets	681,202	651,146
Total assets	14,935,233	14,908,420
Current liabilities
Income taxes payable	3,783	5,524
Accrued payroll and benefits	373,216	469,143
Accrued expenses	366,682	309,312
Current maturities of long-term debt	426,990	459,987
Total current liabilities	2,150,583	2,332,296
Long-term debt	2,804,017	2,611,069
Deferred income taxes	902,186	944,768
Other liabilities	133,201	180,760
Total liabilities	5,989,987	6,068,893
Commitments and contingencies
Redeemable noncontrolling interests	171,212	171,212
Equity
Common stock voting, $.0025 par value; 900,000,000 shares authorized; 268,377,165 and 268,112,991 shares issued; and 151,117,153 and 160,018,100 shares outstanding, as of December 31, 2024 and 2023, respectively	652	651
Treasury stock, at cost; 117,260,012 and 108,094,891 shares, as of December 31, 2024 and 2023, respectively	(7,094,266)	(5,897,606)
Additional paid-in capital	1,229,819	1,217,610
Retained earnings	14,798,082	13,545,590
Accumulated other comprehensive income		421
Total Steel Dynamics, Inc. equity	8,934,287	8,866,666
Noncontrolling interests	(160,253)	(198,351)
Total equity	8,774,034	8,668,315
Total liabilities and equity	14,935,233	14,908,420
Unrelated parties
Current assets
Accounts receivable, net	1,362,969	1,535,062
Current liabilities
Accounts payable	972,645	1,078,645
Related parties
Current assets
Accounts receivable, net	54,230	73,245
Current liabilities
Accounts payable	$ 7,267	$ 9,685

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
CONSOLIDATED BALANCE SHEETS
Allowance for doubtful accounts receivable, current (in dollars)	$ 7,728	$ 8,480
Common stock voting, par value (in dollars per share)	$ 0.0025	$ 0.0025
Common stock voting, shares authorized (in shares)	900,000,000	900,000,000
Common stock voting, shares issued (in shares)	268,377,165	268,112,991
Common stock voting, shares outstanding (in shares)	151,117,153	160,018,100
Treasury stock, shares (in shares)	117,260,012	108,094,891

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Total net sales	$ 17,540,390	$ 18,795,316	$ 22,260,774
Costs of goods sold	14,737,804	14,749,433	16,142,943
Gross profit	2,802,586	4,045,883	6,117,831
Selling, general and administrative expenses	664,119	588,621	545,621
Profit sharing	164,904	272,033	452,551
Amortization of intangible assets	30,526	34,048	27,837
Operating income	1,943,037	3,151,181	5,091,822
Interest expense, net of capitalized interest	56,347	76,484	91,538
Other (income) expense, net	(96,191)	(144,246)	(20,785)
Income before income taxes	1,982,881	3,218,943	5,021,069
Income tax expense	432,925	751,611	1,141,577
Net income	1,549,956	2,467,332	3,879,492
Net income attributable to noncontrolling interests	(12,822)	(16,450)	(16,818)
Net income attributable to Steel Dynamics, Inc.	$ 1,537,134	$ 2,450,882	$ 3,862,674
Basic earnings per share attributable to Steel Dynamics, Inc. stockholders (in dollars per share)	$ 9.89	$ 14.72	$ 21.06
Weighted average common shares outstanding (in shares)	155,420	166,552	183,393
Diluted earnings per share attributable to Steel Dynamics, Inc. stockholders, including the effect of assumed conversions when dilutive (in dollars per share)	$ 9.84	$ 14.64	$ 20.92
Weighted average common shares and share equivalents outstanding (in shares)	156,136	167,431	184,622
Dividends declared per share (in dollars per share)	$ 1.84	$ 1.7	$ 1.36
Unrelated parties
Total net sales	$ 16,819,648	$ 18,115,312	$ 21,469,251
Related parties
Total net sales	$ 720,742	$ 680,004	$ 791,523

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 1,549,956	$ 2,467,332	$ 3,879,492
Other comprehensive income (loss) - net unrealized gain (loss) on cash flow hedging derivatives, net of income tax benefits of $135, $149, and income tax expense of $937 for 2024, 2023 and 2022, respectively	(421)	(468)	2,980
Comprehensive income	1,549,535	2,466,864	3,882,472
Comprehensive income attributable to noncontrolling interests	(12,822)	(16,450)	(16,818)
Comprehensive income attributable to Steel Dynamics, Inc.	$ 1,536,713	$ 2,450,414	$ 3,865,654

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net unrealized gain (loss) on cash flow hedging derivatives income tax (benefits) expense	$ (135)	$ (149)	$ 937

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Treasury Stock, Common [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest [Member]	Redeemable Noncontrolling Interests [Members]	Total
Balances at Dec. 31, 2021	$ 649	$ (2,674,267)	$ 1,218,933	$ 7,761,417	$ (2,091)	$ (195,884)	$ 211,414	$ 6,108,757
Balances, Common Shares at Dec. 31, 2021	194,998,000
Balances, Treasury Shares at Dec. 31, 2021		72,227,000
Dividends declared				(245,287)				(245,287)
Noncontrolling investors, net			630	(2,495)		(36,989)	(29,911)	(38,854)
Share repurchases		$ (1,800,905)						$ (1,800,905)
Share repurchases (in shares)	(22,996,000)	22,996,000						23,000,000
Equity-based compensation	$ 1	$ 15,659	(6,997)	(544)				$ 8,119
Equity-based compensation (in shares)	934,000	(397,000)
Net income				3,862,674		16,818		3,879,492
Other comprehensive (loss) income, net of tax					2,980			2,980
Balances at Dec. 31, 2022	$ 650	$ (4,459,513)	1,212,566	11,375,765	889	(216,055)	181,503	7,914,302
Balances, Common Shares at Dec. 31, 2022	172,936,000
Balances, Treasury Shares at Dec. 31, 2022		94,826,000
Dividends declared				(280,501)				(280,501)
Noncontrolling investors, net						1,254	(10,291)	1,254
Share repurchases		$ (1,452,203)						$ (1,452,203)
Share repurchases (in shares)	(13,394,000)	13,394,000						13,400,000
Equity-based compensation	$ 1	$ 14,110	5,044	(556)				$ 18,599
Equity-based compensation (in shares)	476,000	(125,000)
Net income				2,450,882		16,450		2,467,332
Other comprehensive (loss) income, net of tax					(468)			(468)
Balances at Dec. 31, 2023	$ 651	$ (5,897,606)	1,217,610	13,545,590	421	(198,351)	171,212	$ 8,668,315
Balances, Common Shares at Dec. 31, 2023	160,018,000							160,018,100
Balances, Treasury Shares at Dec. 31, 2023		108,095,000						108,094,891
Dividends declared				(284,122)				$ (284,122)
Noncontrolling investors, net			1,350			25,276		26,626
Share repurchases		$ (1,212,164)						$ (1,212,164)
Share repurchases (in shares)	(9,432,000)	9,432,000						9,400,000
Equity-based compensation	$ 1	$ 15,504	10,859	(520)				$ 25,844
Equity-based compensation (in shares)	531,000	(267,000)
Net income				1,537,134		12,822		1,549,956
Other comprehensive (loss) income, net of tax					$ (421)			(421)
Balances at Dec. 31, 2024	$ 652	$ (7,094,266)	$ 1,229,819	$ 14,798,082		$ (160,253)	$ 171,212	$ 8,774,034
Balances, Common Shares at Dec. 31, 2024	151,117,000							151,117,153
Balances, Treasury Shares at Dec. 31, 2024		117,260,000						117,260,012

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating activities:
Net income	$ 1,549,956	$ 2,467,332	$ 3,879,492
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	478,907	437,804	384,202
Equity-based compensation	66,589	61,744	59,240
Deferred income taxes	(42,583)	55,665	37,186
Other adjustments	(5,507)	(19,716)	(1,795)
Changes in certain assets and liabilities:
Accounts receivable	191,108	446,765	(110,560)
Inventories	(221,036)	232,282	413,262
Other assets	(13,718)	(23,777)	(6,884)
Accounts payable	(67,361)	(30,148)	(289,042)
Income taxes receivable/payable	10,183	56,756	31,623
Accrued expenses	(102,035)	(164,779)	63,679
Net cash provided by operating activities	1,844,503	3,519,928	4,460,403
Investing activities:
Purchases of property, plant and equipment	(1,868,006)	(1,657,905)	(908,902)
Purchases of short-term investments	(739,340)	(1,145,493)	(927,584)
Proceeds from maturities of short-term investments	1,312,294	1,054,742	297,950
Business combinations, net of cash acquired			(134,090)
Investments in unconsolidated affiliates			(222,480)
Other investing activities	(8,308)	(221,593)	15,837
Net cash used in investing activities	(1,303,360)	(1,970,249)	(1,879,269)
Financing activities:
Issuance of current and long-term debt	2,482,919	1,365,664	1,465,257
Repayment of current and long-term debt	(2,324,058)	(1,367,553)	(1,507,475)
Dividends paid	(282,616)	(271,317)	(237,163)
Purchases of treasury stock	(1,212,164)	(1,452,203)	(1,800,905)
Other financing activities	(16,678)	(51,725)	(116,298)
Net cash used in financing activities	(1,352,597)	(1,777,134)	(2,196,584)
Increase (decrease) in cash and equivalents, and restricted cash	(811,454)	(227,455)	384,550
Cash and equivalents, and restricted cash at beginning of period	1,406,464	1,633,919	1,249,369
Cash and equivalents, and restricted cash at end of period	595,010	1,406,464	1,633,919
Supplemental disclosure information:
Cash paid for interest	100,978	103,165	100,994
Cash paid for income taxes, net	$ 463,763	$ 642,667	$ 1,063,844

Description of the Business and

Description of the Business and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2024
Description of the Business and Summary of Significant Accounting Policies
Description of the Business and Significant Accounting Policies	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 one of the largest and most diversified domestic steel producers and metals recycler, combined with a meaningful steel fabrication manufacturing platform. The company has four reporting segments: steel operations, metals recycling operations, steel fabrication operations, and aluminum operations. Effective the fourth quarter 2024, results from an entity previously reported within the metals recycling operations segment were moved to the aluminum operations segment, consistent with a change in how the company’s chief operating decision maker manages the business. Segment information provided within this Form 10-K, including that within Note 12. Segment Information Steel Operations Segment Steel operations include the company’s electric arc furnace (EAF) steel mills, including Butler Flat Roll Division, Columbus Flat Roll Division, Southwest-Sinton Flat Roll Division, Structural and Rail Division, Engineered Bar Products Division, Roanoke Bar Division, and Steel of West Virginia, steel coating and processing operations at The Techs, Heartland Flat Roll Division, United Steel Supply (USS) – 90% equity interest as of April 1, 2023, Vulcan Threaded Products, warehouse operations in Mexico, and SDI Biocarbon Solutions, a joint venture to construct and operate a biocarbon production facility, of which SDI has a 75% equity interest. Metals Recycling Operations Segment Metals recycling operations include the company’s OmniSource ferrous and nonferrous processing, transportation, marketing, brokerage, and scrap management services primarily throughout the United States and in Central and Northern Mexico. Steel Fabrication Operations Segment Steel fabrication operations include the company’s New Millennium Building Systems joist and deck plants located throughout the United States, and in Northern Mexico. Revenues from these plants are generated from the fabrication of girders, steel joists and steel deck used within the non-residential construction industry. Aluminum Operations Segment Aluminum operations include the recycled aluminum flat rolled products mill nearing completion of construction in Columbus, Mississippi, two satellite recycled aluminum slab centers in the southwest United States and Central Mexico, and an entity with aluminum operations, formerly included in the results of the metals recycling operations segment. The flat rolled products mill is a joint venture with Unity Aluminum, Inc. of which SDI has a 94.4% equity interest. The aluminum flat rolled products mill and the Mexico and US recycled aluminum slab centers are expected to begin operations in mid to late 2025. Other Other operations consist of subsidiary operations that are below the quantitative thresholds required for reportable segments and primarily consist of joint ventures and the company’s idled Minnesota ironmaking operations. Also included in “Other” are certain unallocated corporate accounts, such as the company’s senior unsecured credit facility, senior notes, certain other investments, and certain profit sharing expenses. Note 1. Description of the Business and Summary of Significant Accounting Policies (Continued) 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 intercompany accounts and transactions. Noncontrolling and redeemable noncontrolling interests represent the noncontrolling owners' proportionate share in the equity, income, or losses of the company’s majority-owned or controlled consolidated subsidiaries. Redeemable noncontrolling interests related to USS (owned 90% by SDI) are $60.0 million at December 31, 2024 and 2023. Redeemable noncontrolling interests related to Mesabi Nugget (owned 86% by SDI) are $111.2 million at December 31, 2024 and 2023. Use of Estimates These consolidated 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 consolidated 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; allowances for credit losses 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 from Contracts with Customers In the steel, metals recycling, and aluminum operations segments, revenue is recognized at the point in time the performance obligation is satisfied, and control of the product is transferred to the customer upon shipment or delivery, at the amount of consideration the company expects to receive, including any variable consideration. The variable consideration included in the company’s steel operations segment contracts, which is not constrained, includes estimated product returns and customer claims based on historical experience, and may include volume rebates which are recorded on an expected value basis. Revenue recognized is limited to the amount the company expects to receive. The company does not exercise significant judgments in determining the timing of satisfaction of performance obligations or the transaction price. Shipment of products to customers is considered a fulfillment activity with amounts billed to customers included in sales and costs associated with such activities included in cost of goods sold. The company’s steel fabrication operations segment recognizes revenue over time at the amount of consideration the company expects to receive. Revenue is measured on an output method representing completed fabricated tons to date as a percentage of total tons required for each contract. Revenue from fabrication of tons remaining on partially fabricated customer contracts as of a reporting date, and future revenue from yet to be fabricated customer contracts, has not been disclosed under the practical expedient in Accounting Standards Codification (ASC) 606, Revenue from Contracts with Customers (ASC 606), paragraph ASC 606-10-50-14 related to customer contracts with expected duration of one year or less. The company does not exercise significant judgments in determining the timing of satisfaction of performance obligations or the transaction price. Shipment of products to customers, which occurs after control over the product has transferred to the customer and revenue is recognized, is considered a fulfillment activity with amounts billed to customers included in sales and costs associated with such activities included in cost of goods sold. Payments from customers are generally due within 30 days of invoicing, which generally occurs upon shipment of the products. Shipment for the steel fabrication operations segment generally occurs within 30 days of satisfaction of the performance obligation and revenue recognition. The company does not have financing components. Payments from customers have historically been within these terms, however, payments for non-U.S. sales may extend longer. Note 1. Description of the Business and Summary of Significant Accounting Policies (Continued) Refer to Note 12. Segment Information Credit Losses The company is exposed to credit risk in the event of nonpayment of accounts receivable by customers. The company mitigates its exposure to credit risk, which it generally extends 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. The allowance for credit losses for accounts receivable is based on the company’s reasonable estimate of known credit risks and historical experience, adjusted for current and anticipated economic and other pertinent factors affecting the company’s customers, that may differ from historical experience. Customer accounts receivable are written off when all collection efforts have been exhausted and the amounts are deemed uncollectible. At December 31, 2024 and 2023, the company reported $1,417.2 million and $1,608.3 million, respectively, of accounts receivable, net of allowances for credit losses of $7.7 million and $8.5 million, respectively. Changes in the allowance were not significant for the years ended December 31, 2024, 2023, or 2022. Cash and Equivalents, and Restricted Cash 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. The balance of cash, cash equivalents and restricted cash in the consolidated statements of cash flows includes restricted cash of Short-Term Investments Short-term investments include investments with maturity dates of longer than three months but less than one year when purchased. The company’s short-term investments are classified as trading securities. The short-term investments held as of December 31, 2024 consisted of commercial paper ($19.7 million), US Treasuries ($113.1 million), and certificates of deposit ($15.0 million). Short-term investments held as of December 31, 2023 consisted of commercial paper ($146.2 million), US Treasuries ($564.9 million), and certificates of deposit ($10.1 million). Interest income from invested cash and short-term investments was $90.1 million, $111.9 million, and $29.3 million for the years ended December 31, 2024, 2023, and 2022, respectively, and is recorded in other (income) expense, net as earned. Inventories Inventories are stated at lower of cost or net realizable value. Cost is determined using a weighted average cost method for raw materials (including scrap and purchased steel substrate) and supplies, and on a first-in, first-out basis for other inventory. Inventory consisted of the following at December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ ​ Raw materials $ 1,323,920 ​ $ 1,226,272 ​ ​ Supplies ​ 805,035 ​ ​ 711,653 ​ ​ Work in progress ​ 269,031 ​ ​ 296,932 ​ ​ Finished goods ​ 715,747 ​ ​ 659,775 ​ ​ Total inventories $ 3,113,733 ​ $ 2,894,632 ​ ​ Note 1. Description of the Business and Summary of Significant Accounting Policies (Continued) 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, except for assets acquired in acquisitions which are valued at fair value at the purchase date. The company assigns each fixed asset a useful life ranging from 3 to 15 years for plant, machinery and equipment, and 5 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 steel operations segment assets, based on units produced, subject to minimum and maximum levels. Depreciation expense was $441.2 million, $397.0 million, and $349.4 million for the years ended December 31, 2024, 2023, and 2022, respectively. The company’s property, plant and equipment consisted of the following at December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ ​ Land and improvements ​ $ 801,210 ​ $ 693,166 ​ ​ Buildings and improvements ​ ​ 1,487,742 ​ ​ 1,255,274 ​ ​ Plant, machinery and equipment ​ ​ 7,666,513 ​ ​ 6,887,985 ​ ​ Construction in progress ​ ​ 2,767,013 ​ ​ 2,096,489 ​ ​ ​ ​ ​ 12,722,478 ​ ​ 10,932,914 ​ ​ Less accumulated depreciation ​ ​ 4,604,490 ​ ​ 4,198,696 ​ ​ Property, plant and equipment, net ​ $ 8,117,988 ​ $ 6,734,218 ​ ​ Intangible Assets The company’s intangible assets consisted of the following at December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ ​ ​ ​ ​ Useful ​ Amortization ​ ​ ​ 2024 ​ 2023 ​ Life ​ Period ​ ​ Customer, vendor and scrap generator relationships $ 444,812 ​ $ 444,812 ​ 8 to 25 years ​ 22 years ​ ​ Trade names ​ 147,950 ​ ​ 147,950 ​ 15 to 25 years ​ 19 years ​ ​ Other ​ - ​ ​ 600 ​ ​ ​ ​ ​ ​ ​ ​ 592,762 ​ ​ 593,362 ​ ​ ​ 22 years ​ ​ Less accumulated amortization ​ 365,528 ​ ​ 335,603 ​ ​ ​ ​ ​ ​ ​ $ 227,234 ​ $ 257,759 ​ ​ ​ ​ ​ ​ The company utilizes an accelerated amortization methodology for customer, vendor and scrap generator relationships in order to follow the pattern in which the economic benefits of the amounts are anticipated to be consumed. Trade names are amortized using a straight-line methodology. Amortization of intangible assets was $30.5 million, $34.0 million, and $27.8 million for the years ended December 31, 2024, 2023, and 2022, respectively. ​ ​ Note 1. Description of the Business and Summary of Significant Accounting Policies (Continued) Estimated amortization expense related to amortizable intangibles for the years ending December 31 is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2025 ​ $ 27,464 ​ ​ 2026 ​ ​ 25,562 ​ ​ 2027 ​ ​ 23,163 ​ ​ 2028 ​ ​ 21,953 ​ ​ 2029 ​ ​ 19,583 ​ ​ Thereafter ​ ​ 109,509 ​ ​ Total ​ $ 227,234 ​ ​ 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 assets to its carrying amount. The company considers various factors and determines 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, the company’s strategy and capital planning, and the economic environment in markets to be served. Goodwill The company’s goodwill consisted of the following at December 31, 2024 and 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Steel Operations Segment ​ $ 272,133 ​ ​ ​ Aluminum Operations Segment ​ ​ 14,000 ​ ​ ​ Metals Recycling Operations Segment ​ ​ 189,413 ​ ​ ​ Steel Fabrication Operations Segment ​ ​ 1,925 ​ ​ ​ ​ ​ $ 477,471 ​ ​ ​ In the fourth quarter 2024, results from an entity previously included in the metals recycling operations segment were moved to the aluminum operations segment, which also resulted in $14 million of goodwill ​ Impairment of Goodwill At least once annually (as of October 1), or when indicators of impairment exist, the company performs a goodwill impairment analysis. Goodwill is allocated to various reporting units, which are generally one level below the company’s operating segments. If the fair value exceeds the carrying value of the reporting unit, there is no impairment. If the carrying amount exceeds the fair value, the company recognizes an impairment loss in the amount by which the carrying value of the net assets assigned to the reporting unit exceeds the fair value of the reporting unit, with the impairment loss not to exceed the amount of goodwill allocated to the reporting unit. The company has the option to consider qualitative factors to assess if it is more likely than not that the fair value of a reporting unit exceeds its carrying value. If elected to bypass the qualitative assessment or if indications of a potential impairment exist, the company performs a quantitative test. Note 1. Description of the Business and Summary of Significant Accounting Policies (Continued) When conducting a qualitative assessment, the company considers the impact of several factors on the company overall and each reporting unit individually including the timing and results of prior quantitative tests performed, changes in the carrying amount of the reporting unit, macroeconomic conditions (including changes in interest and discount rates), industry and market conditions, recent and projected financial performance, the company’s competitive position and other factors. When conducting a quantitative test, 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 for some years by using a market approach based upon an analysis of valuation metrics of comparable peer companies, using Level 3 fair value inputs as provided for under ASC 820, Fair Value Measurement . ​ No impairment was identified during the company’s 2024, 2023 or 2022 annual goodwill impairment analysis. During 2024, the company performed a qualitative assessment and performed quantitative tests in 2023 and 2022. ​ Equity-Based Compensation The company has several stock-based employee compensation plans which are more fully described in Note 6. Equity-Based Incentive Plans. Compensation expense for restricted stock units, deferred stock units, restricted stock, stock appreciation awards, 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. The company recognizes forfeitures as they occur. Compensation expense for these stock-based employee compensation plans was $65.6 million, $60.1 million, and $69.2 million for the years ended December 31, 2024, 2023, and 2022, 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 restricted stock units, deferred stock units, restricted stock, and performance awards, and are excluded from the computation in periods in which they have an anti-dilutive effect. There were 269,000 anti-dilutive common stock equivalents as of and for the year ended December 31, 2024. There were no anti-dilutive common stock equivalents as of and for the years ended December 31, 2023, and 2022. ​ Note 1. Description of the Business and Summary of Significant Accounting Policies (Continued) 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): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ ​ 2023 ​ ​ Net Income ​ Shares ​ Per Share ​ ​ Net Income ​ Shares ​ Per Share ​ ​ (Numerator) ​ (Denominator) ​ Amount ​ ​ (Numerator) ​ (Denominator) ​ Amount Basic earnings per share ​ $ 1,537,134 ​ ​ 155,420 ​ $ 9.89 ​ ​ $ 2,450,882 ​ ​ 166,552 ​ $ 14.72 Dilutive common share equivalents ​ ​ - ​ ​ 716 ​ ​ ​ ​ ​ ​ - ​ ​ 879 ​ ​ ​ Diluted earnings per share ​ $ 1,537,134 ​ ​ 156,136 ​ $ 9.84 ​ ​ $ 2,450,882 ​ ​ 167,431 ​ $ 14.64 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 ​ ​ Net Income ​ Shares ​ Per Share ​ ​ (Numerator) ​ (Denominator) ​ Amount ​ Basic earnings per share $ 3,862,674 ​ ​ 183,393 ​ $ 21.06 ​ Dilutive common share equivalents ​ - ​ ​ 1,229 ​ ​ ​ ​ Diluted earnings per share $ 3,862,674 ​ ​ 184,622 ​ $ 20.92 ​ ​ 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. When advantageous, the company places its temporary cash 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. Derivative Financial Instruments The company routinely enters into forward exchange traded futures to manage price risk associated with nonferrous metal inventory, as well as purchases and sales of nonferrous (primarily aluminum and copper) and ferrous metals, to reduce exposure to commodity related price fluctuations. The company does not enter into these derivative financial instruments for speculative purposes. 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 for fair value hedges. 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 has derivative financial instruments in the form of forward contracts in various metallic commodities and those related to managing fluctuations in foreign exchange rates. 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 in earnings. Note 1. Description of the Business and Summary of Significant Accounting Policies (Continued) The fair value of the Company’s derivative instruments, along with required margin deposit amounts with the same counterparty under master netting arrangements, totaled $26.0 million and $24.0 million at December 31, 2024 and 2023, respectively, and are reflected in other current assets in the consolidated balance sheets. Total gains and losses related to derivatives in fair value hedging relationships, as well as those not designated as hedging instruments, are recognized in costs of goods sold and were insignificant for the years ended December 31, 2024, 2023, and 2022. Derivatives accounted for as cash flow hedges, for which gains and losses are recognized in other comprehensive income, along with net amounts reclassified from accumulated other comprehensive income, were insignificant for the years ended December 31, 2024, 2023, and 2022. ​ Recently Adopted Accounting Pronouncements In November 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures Segment Information Recently Issued Not Yet Adopted Accounting Pronouncements In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures In November 2024, the FASB issued ASU 2024-03, Income Statement Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses

Business Combinations and Inves

Business Combinations and Investments in Unconsolidated Affiliates	12 Months Ended
	Dec. 31, 2024
Business Combinations and Investments in Unconsolidated Affiliates
Business Combinations and Investments in Unconsolidated Affiliates	Note 2. Business Combinations and Investments in Unconsolidated Affiliates Business Combinations ROCA The company acquired 100% of ROCA ACERO, S.A. de C.V. (ROCA) on October 1, 2022. The acquisition of ROCA is part of the company’s North American raw material procurement strategy. ROCA is headquartered in Monterrey, Mexico, and operates ferrous and nonferrous scrap facilities strategically positioned near high-volume industrial scrap sources located throughout Central and Northern Mexico. The transaction was funded with available cash. Post ​ Note 2. Business Combinations and Investments in Unconsolidated Affiliates (Continued) Aluminum Dynamics The company obtained a 94.4% equity interest in a joint venture concurrently formed with Unity Aluminum, Inc. on July 29, 2022, for the construction and operation of a new state-of-the-art lower-carbon recycled aluminum flat rolled products mill. The transaction was funded with available cash. Operating results from and after July 29, 2022, are reflected in the company’s consolidated financial statements in the aluminum operations segment. ​ United Steel Supply The company purchased a 75% equity interest in United Steel Supply, LLC on March 1, 2019. On April 1, 2022, the company purchased an additional 12.5% equity interest in USS. On April 1, 2023, a noncontrolling member of USS exercised its option to require SDI to purchase its 2.5% equity interest, increasing SDI’s ownership to 90%. The remaining noncontrolling members have the option to require SDI to purchase the remaining 10% equity interest of USS on or after February 28, 2025. The USS noncontrolling interest is therefore reflected in redeemable noncontrolling interest in the consolidated balance sheets. ​ Investments in Unconsolidated Affiliates The company purchased a 45% minority equity interest in New Process Steel, L.P. (NPS) on January 31, 2022. NPS is a metals solutions and distribution supply-chain management company headquartered in Houston, Texas, with a focus toward growing its value-added manufacturing applications. On February 28, 2022, the company also purchased a minority equity interest in Aymium, a producer of renewable biocarbon products. As the company does not have power to control these entities, the company accounts for these investments using the equity method of accounting, which are recorded in Other Assets (noncurrent) in the company’s consolidated balance sheets with related activity recorded in Other (Income) Expense, net. Profits or losses from transactions with NPS are eliminated until realized by the majority equity interest owner. ​

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2024
Long-Term Debt.
Long-Term Debt	Note 3. Long-Term Debt The company’s borrowings consisted of the following at December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ ​ ​ ​ 2.800% senior notes due 2024 $ - ​ $ 400,000 ​ ​ ​ ​ 2.400% senior notes due 2025 ​ 400,000 ​ ​ 400,000 ​ ​ ​ ​ 5.000% senior notes due 2026 ​ 400,000 ​ ​ 400,000 ​ ​ ​ ​ 1.650% senior notes due 2027 ​ 350,000 ​ ​ 350,000 ​ ​ ​ ​ 3.450% senior notes due 2030 ​ 600,000 ​ ​ 600,000 ​ ​ ​ ​ 3.250% senior notes due 2031 ​ 500,000 ​ ​ 500,000 ​ ​ ​ ​ 5.375% senior notes due 2034 ​ 600,000 ​ ​ - ​ ​ ​ ​ 3.250% senior notes due 2050 ​ 400,000 ​ ​ 400,000 ​ ​ ​ ​ Other obligations ​ 28,803 ​ ​ 61,836 ​ ​ ​ ​ Total debt ​ 3,278,803 ​ ​ 3,111,836 ​ ​ ​ ​ Less debt issuance costs and original issue discounts ​ 47,796 ​ ​ 40,780 ​ ​ ​ ​ Total amounts outstanding ​ 3,231,007 ​ ​ 3,071,056 ​ ​ ​ ​ Less current maturities ​ 426,990 ​ ​ 459,987 ​ ​ ​ ​ Long-term debt $ 2,804,017 ​ $ 2,611,069 ​ ​ ​ Financing Activity ​ In July 2024, the company issued $600.0 million of 5.375% notes due 2034. Proceeds from these notes were used for general corporate purposes, including the repayment of the company’s 2.800% senior notes due December 2024, working capital, capital expenditures, advances for or investments in the company’s subsidiaries, acquisitions, redemption and repayment of other outstanding indebtedness, and purchases of the company’s common stock. Note 3. Long-Term Debt (Continued) Senior Credit Facility, due 2028 ​ On July 19, 2023, the company entered into an unsecured credit agreement comprised of a senior unsecured credit facility (Facility), which provides a $1.2 billion unsecured Revolver, maturing July 2028. Subject to certain conditions, the company has the opportunity to increase the Facility size by $500.0 million. The unsecured Facility is available to fund working capital, capital expenditures, and other general corporate purposes. The Facility contains financial covenants and other covenants pertaining to the company’s ability to incur indebtedness and permit liens on certain assets. The company’s ability to borrow funds within the terms of the unsecured Facility is dependent upon its continued compliance with financial and other covenants. At December 31, 2024, the company had $1.2 billion of availability on the Facility, $9.3 million of outstanding letters of credit and other obligations which reduce availability, and there were no borrowings outstanding. ​ The Facility pricing grid is adjusted quarterly and is based on either the company’s leverage of net debt (as defined in the Facility) to last-twelve-months (LTM) consolidated Adjusted EBITDA as defined in the Facility (earnings before interest, taxes, depreciation, amortization, and certain other non-cash items as allowed in the Facility), or the company’s credit ratings. The minimum pricing is adjusted Secured Overnight Financing Rate ( SOFR SOFR The financial covenants under the Facility state that the company must maintain an interest coverage ratio of not less than 2.50 :1.00. The company’s interest coverage ratio is calculated by dividing its LTM consolidated Adjusted EBITDA by its LTM gross interest expense, less amortization of financing fees. In addition, a debt to capitalization ratio of not more than 0.60 :1.00 must be maintained. At December 31, 2024, the company’s interest coverage ratio and debt to capitalization ratio were 21.68 :1.00 and 0.27 :1.00, respectively. The company was, therefore, in compliance with these covenants at December 31, 2024, and anticipates remaining in compliance during the next twelve months. Senior Unsecured Notes The company has seven different tranches of senior unsecured notes (Notes) outstanding. These Notes are in equal right of payment with all existing and future senior unsecured indebtedness and are senior in right of payment to all subordinated indebtedness. These Notes contain provisions that allow the company to redeem the Notes on or after the dates and at redemption prices (expressed as a percentage of principal amount) listed below. ​ U.S. Treasury rate ​ The company’s $400.0 million of 5.000% senior notes due 2026 mature on December 15, 2026, with interest payable semi-annually. Early redemption was permitted as of December 15, 2024, at 100.000%. ​ The company’s $350.0 million of 1.650% senior notes due 2027 mature on October 15, 2027, with interest payable semi-annually. Early redemption is permitted any time prior to August 15, 2027, at the greater of par or a make-whole price of the remaining payments to be made discounted at the applicable U.S. Treasury rate ​ The company’s $600.0 million of 3.450% senior notes due 2030 mature on April 15, 2030, with interest payable semi-annually. Early redemption is permitted any time prior to January 15, 2030, at the greater of par or a make-whole price of the remaining payments to be made discounted at the applicable U.S. Treasury rate ​ Note 3. Long-Term Debt (Continued) The company’s $500.0 million of 3.250% senior notes due 2031 mature on January 15, 2031, with interest payable semi-annually. Early redemption is permitted any time prior to October 15, 2030, at the greater of par or a make-whole price of the remaining payments to be made discounted at the applicable U.S. Treasury rate ​ The company’s $600.0 million of 5.375% senior notes due 2034 mature on August 15, 2034, with interest payable semi-annually. Early redemption is permitted any time prior to May 15, 2034, at the greater of par or a make-whole price of the remaining payments to be made discounted at the applicable U.S. Treasury rate ​ The company’s $400.0 million of 3.250% senior notes due 2050 mature on October 15, 2050, with interest payable semi-annually. Early redemption is permitted any time prior to April 15, 2050, at the greater of par or a make-whole price of the remaining payments to be made discounted at the applicable U.S. Treasury rate ​ Other Obligations Secured Loans. One of the company’s controlled subsidiaries has a secured credit agreement, which matures in June 2028, and provides a revolving variable rate credit facility of up to $125.0 million, subject to a borrowing base determined from eligible accounts receivable and inventory. Interest, which was 6.40% at December 31, 2024, is payable monthly. Amounts due under the credit facility were $26.4 million and $59.8 million at December 31, 2024, and 2023, respectively. Outstanding Debt Maturities Maturities of outstanding debt as of December 31, 2024, are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ 2025 ​ $ 427,442 ​ ​ 2026 ​ ​ 400,896 ​ ​ 2027 ​ ​ 350,465 ​ ​ 2028 ​ ​ - ​ ​ 2029 ​ ​ - ​ ​ Thereafter ​ ​ 2,100,000 ​ ​ ​ ​ $ 3,278,803 ​ ​ The company capitalizes interest on all qualifying construction in progress assets. For the years ended December 31, 2024, 2023, and 2022, total interest costs incurred were $123.1 million, $109.5 million, and $107.4 million, respectively, of which $66.8 million, $33.0 million, and $15.8 million, respectively, were capitalized

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2024
Income Taxes
Income Taxes	Note 4. Income Taxes Components of earnings before income taxes and noncontrolling interests for the years ended December 31 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ 2022 ​ ​ United States income $ 1,992,814 ​ $ 3,198,048 ​ $ 4,996,762 ​ ​ Foreign income (loss) ​ (9,933) ​ ​ 20,895 ​ ​ 24,307 ​ ​ Total income before income taxes $ 1,982,881 ​ $ 3,218,943 ​ $ 5,021,069 ​ ​ The company files a consolidated federal income tax return. The provision for income tax expense for the years ended December 31 is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ 2022 ​ ​ Current income tax expense ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal $ 409,586 ​ $ 600,499 ​ $ 946,016 ​ ​ State ​ 57,942 ​ ​ 91,965 ​ ​ 152,758 ​ ​ Foreign ​ 7,980 ​ ​ 3,482 ​ ​ 8,605 ​ ​ Total current ​ 475,508 ​ ​ 695,946 ​ ​ 1,107,379 ​ ​ Deferred income tax expense (benefit) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ (26,311) ​ ​ 38,172 ​ ​ 22,168 ​ ​ State ​ (12,476) ​ ​ 15,355 ​ ​ 13,333 ​ ​ Foreign ​ (3,796) ​ ​ 2,138 ​ ​ (1,303) ​ ​ Total deferred ​ (42,583) ​ ​ 55,665 ​ ​ 34,198 ​ ​ Total income tax expense $ 432,925 ​ $ 751,611 ​ $ 1,141,577 ​ ​ A reconciliation of the statutory rates to the actual effective tax rates for the years ended December 31 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ 2022 ​ ​ Statutory federal tax rate ​ 21.0 % ​ ​ 21.0 % ​ ​ 21.0 % ​ ​ State income taxes, net of federal benefit ​ 1.8 ​ ​ ​ 2.6 ​ ​ ​ 2.6 ​ ​ ​ Federal research & development credits ​ (0.9) ​ ​ ​ (0.2) ​ ​ ​ (0.6) ​ ​ ​ Other permanent differences ​ (0.1) ​ ​ ​ (0.1) ​ ​ ​ (0.3) ​ ​ ​ Effective tax rate ​ 21.8 % ​ ​ 23.3 % ​ ​ 22.7 % ​ ​ ​ Note 4. Income Taxes (Continued) Significant components of the company’s deferred tax assets and liabilities at December 31 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ ​ Deferred tax assets ​ ​ ​ ​ ​ ​ ​ Accrued expenses and allowances $ 41,031 ​ $ 41,894 ​ ​ Inventories ​ 6,892 ​ ​ 10,685 ​ ​ Net operating loss carryforwards ​ 24,381 ​ ​ 7,663 ​ ​ Amortizable assets ​ 39,657 ​ ​ 5,798 ​ ​ Other ​ 5,916 ​ ​ 9,149 ​ ​ ​ ​ 117,877 ​ ​ 75,189 ​ ​ Less: valuation allowance ​ (1,150) ​ ​ (816) ​ ​ Total net deferred tax assets ​ 116,727 ​ ​ 74,373 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax liabilities ​ ​ ​ ​ ​ ​ ​ Property, plant and equipment ​ (1,014,515) ​ ​ (1,013,045) ​ ​ Other ​ (4,398) ​ ​ (6,096) ​ ​ Total deferred tax liabilities ​ (1,018,913) ​ ​ (1,019,141) ​ ​ Net deferred tax liability $ (902,186) ​ $ (944,768) ​ ​ Certain wholly-owned and controlled subsidiaries of the company file separate federal and state income tax returns. One of the controlled subsidiaries generated federal net operating loss carryforwards in the years 2018 and prior, which were fully utilized as of December 31, 2024, but continues to have state net operating loss carryforwards which expire in the years 2034 through 2039. Annually, the company evaluates the realizability of the net deferred tax assets for this controlled subsidiary. In completing this evaluation, the company considers all available positive and negative evidence in order to determine whether, based on the weight of the evidence, a valuation allowance for its deferred tax assets is necessary. Such evidence includes current operating results, historical results, future reversals of existing taxable temporary differences and expectations for future taxable income (exclusive of the reversal of temporary differences and carryforwards), as well as the implementation of feasible and prudent tax planning strategies. Based on the evidence, the company maintained a valuation allowance of $1,150,000 and $816,000 as of December 31, 2024, and 2023, respectively, with respect to certain state tax credits of the controlled subsidiary. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ 2022 ​ ​ Balance at January 1 $ 31,258 ​ $ 28,646 ​ $ 20,466 ​ ​ Increases related to current year tax positions ​ 5,115 ​ ​ 1,500 ​ ​ 9,600 ​ ​ Increases related to prior year tax positions ​ 263 ​ ​ 1,798 ​ ​ 364 ​ ​ Decreases related to prior year tax positions ​ (6,949) ​ ​ (686) ​ ​ (1,784) ​ ​ Balance at December 31 $ 29,687 ​ $ 31,258 ​ $ 28,646 ​ ​ Included in the balance of unrecognized tax benefits at December 31, 2024 and 2023 are potential benefits of $26.4 million and $27.8 million, respectively, that, if recognized, would affect the effective tax rate. The company recognizes interest and penalties related to its tax contingencies on a net-of-tax basis in income tax expense. During the years ended December 31, 2024, 2023, and 2022, the company recognized expense from the increase of interest expense and penalties of $710,000, $1,560,000, and $480,000, respectively, net of tax. In addition to the unrecognized tax benefits in the table above, the company had $4.2 million and $3.2 million accrued for the payment of interest and penalties at December 31, 2024 and 2023, respectively. ​ Note 4. Income Taxes (Continued) It is reasonably possible that the amount of unrecognized tax benefits could change in the next twelve months in an amount ranging from zero to $12.0 million, as a result of the expiration of the statute of limitations and other federal and state income tax audits. The company files income tax returns in the U.S. federal jurisdiction as well as income tax returns in various state jurisdictions. The tax years 2021 through 2023 remain open to examination by the Internal Revenue Service and various state and local jurisdictions.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2024
Shareholders' Equity
Shareholders' Equity	Note 5. Shareholders’ Equity Cash Dividends The company declared cash dividends of $284.1 million, or $1.84 per common share, during 2024; $280.5 million, or $1.70 per common share, during 2023; and $245.3 million, or $1.36 per common share, during 2022. The company paid cash dividends of $282.6 million, $271.3 million, and $237.2 million during 2024, 2023, and 2022, respectively. Treasury Stock In July 2021, the board of directors authorized a share repurchase program of up to $1.0 billion of the company’s common stock. This program was exhausted in April 2022. In February 2022, the board of directors authorized an additional share repurchase program of up to $1.25 billion of the company’s common stock. This program was exhausted in November 2022. In November 2022, the board of directors authorized an additional share repurchase program of up to $1.5 billion of the company’s common stock. This program was exhausted in November 2023. In November 2023, the board of directors authorized an additional share repurchase program of up to $1.5 billion of the company’s common stock. Subsequent to December 31, 2024, in February 2025, the board of directors authorized an additional share repurchase program of up to $1.5 billion of the company’s common stock. Under the share repurchase programs, purchases take place as and when we determine in open market or private transactions made based upon the market price of our common stock, the nature of other investment opportunities or growth projects, our cash flows from operations, and general economic conditions. The share repurchase programs do not require us to acquire any specific number of shares, and may be modified, suspended, extended, or terminated by us at any time. The share repurchase programs do not have an expiration date. The company repurchased 9.4 million shares for $1.2 billion during 2024, 13.4 million shares for $1.5 billion during 2023, and 23.0 million shares for $1.8 billion during 2022 under the share repurchase programs. At December 31, 2024, the company had remaining authorization to repurchase $193.5 million of additional shares under the November 2023 share repurchase program. ​

Equity-Based Incentive Plans

Equity-Based Incentive Plans	12 Months Ended
	Dec. 31, 2024
Equity-Based Incentive Plans
Equity-Based Incentive Plans	Note 6. Equity-Based Incentive Plans 2023 Equity Incentive Plan In May 2023, the company’s shareholders approved the 2023 Equity Incentive Plan (2023 Plan), which supersedes the prior Amended and Restated 2015 Equity Incentive Plan. The 2023 Plan is designed to attract, motivate, and retain qualified persons that are able to make important contributions to the company’s success. To accomplish these objectives, the 2023 Plan provides for awards of equity-based incentives through granting of restricted stock units (RSUs), deferred stock units (DSUs), stock appreciation rights (SARs), performance awards, such as the long-term incentive compensation program (LTIP), restricted stock awards (of which none have been granted), stock options (of which none have been granted), and unrestricted stock awards (of which none have been granted). Under the 2023 Plan, 9.0 million shares of common stock were reserved for grant through December 31, 2033. The 2023 Plan uses a fungible share concept under which any awards that are not a full-value award, such as stock options and stock-settled SARs, will be counted against the share reserve as one share for each share of common stock, and awards that are full-value awards, such as RSUs, DSUs, restricted and unrestricted stock awards, and performance awards, will be counted against the share reserve as 2.09 shares for each share of common stock. The SARs the company has granted to date can only be settled in cash, and thus, do not count against the share reserve. At December 31, 2024, there were 6.2 million shares still available for issuance. Note 6. Equity-Based Incentive Plans (Continued) Substantially all of the company’s full-time, non-union, U.S. team members receive RSUs, which are granted annually in November at no cost to employees and vest 100% over the shorter of two years from grant date or upon the recipient reaching retirement eligible age ( 59½ years Restricted Stock Units A summary of the company’s RSU activity and outstanding RSUs as of December 31, 2024, are presented below (dollars in thousands except grant date fair value): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Aggregate ​ ​ ​ ​ Number ​ Average Grant ​ Intrinsic ​ Unrecognized ​ of RSUs ​ Date Fair Value ​ Value ​ Compensation Outstanding RSUs as of January 1, 2022 1,348,258 ​ $ 43.82 ​ $ 83,686 ​ $ 39,657 Granted 481,926 ​ ​ 98.29 ​ ​ ​ ​ ​ ​ Vested (786,622) ​ ​ 37.38 ​ ​ ​ ​ ​ ​ Forfeited (70,011) ​ ​ 46.82 ​ ​ ​ ​ ​ ​ As of December 31, 2022 973,551 ​ $ 71.80 ​ $ 94,765 ​ $ 44,394 Granted 433,810 ​ ​ 108.95 ​ ​ ​ ​ ​ ​ Vested (517,041) ​ ​ 64.03 ​ ​ ​ ​ ​ ​ Forfeited (40,829) ​ ​ 78.70 ​ ​ ​ ​ ​ ​ As of December 31, 2023 849,491 ​ $ 99.13 ​ $ 101,480 ​ $ 43,073 Granted 374,370 ​ ​ 137.14 ​ ​ ​ ​ ​ ​ Vested (394,675) ​ ​ 94.28 ​ ​ ​ ​ ​ ​ Forfeited (39,874) ​ ​ 104.21 ​ ​ ​ ​ ​ ​ As of December 31, 2024 (nonvested) 789,312 ​ $ 115.47 ​ $ 90,037 ​ $ 54,964 ​ The weighted average remaining life before vesting of the outstanding RSUs as of December 31, 2024, is ​ Long-Term Incentive Compensation Program (LTIP) The company maintains an LTIP performance-based program directed toward key senior leadership of the company, as determined at the discretion of the Compensation Committee of the Board of Directors. Awards are in shares of the company’s common stock using the stock price on the first day of the performance period to convert each key senior executive’s predetermined multiple of annual base salary. The performance period is generally three years; however, transition awards can be issued with a shorter performance period. Performance is measured in terms of equal portions of four growth and profitability measures, as compared to the same measures, similarly treated, of a pre-established group of steel sector competitors. Awards earned can range from zero to 100% of the shares awarded, and award shares vest immediately once earned on the basis of performance. ​ Note 6. Equity-Based Incentive Plans (Continued) The Compensation Committee granted the following three-year performance period awards and transition awards, which have been earned and have or will be issued as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maximum ​ ​ ​ ​ ​ ​ ​ ​ Shares That ​ Award ​ ​ ​ ​ ​ ​ Could Be Issued ​ Earned ​ Award Issued/Issuable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 LTIP Award: ​ ​ ​ ​ ​ ​ ​ ​ Three-year performance period award 360,189 ​ 324,173 ​ 324,173 ​ March 2024 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 LTIP Award: ​ ​ ​ ​ ​ ​ ​ ​ Three-year performance period award 249,759 ​ 249,759 ​ 249,759 ​ March 2025 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 LTIP Award: ​ ​ ​ ​ ​ ​ ​ ​ Three-year performance period award 193,946 ​ * ​ * ​ ​ ​ Two-year performance period transition award 5,517 ​ 4,690 ​ 4,690 ​ March 2025 ​ One-year performance period transition award 3,678 ​ 2,759 ​ 2,759 ​ March 2024 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 LTIP Award: ​ ​ ​ ​ ​ ​ ​ ​ Three-year performance period award 172,425 ​ * ​ * ​ ​ * Not yet earned as performance period not complete. 2018 Executive Incentive Compensation Plan (2018 Executive Plan) The 2018 Executive Plan provides for eligibility of certain senior leadership of the company to receive cash and stock bonuses based on predetermined formulas. The company’s shareholders approved the 2018 Executive Plan in May 2018 and 2.0 million shares of company stock were reserved for grant through February 28, 2028. At times a portion of the bonus may be distributed in shares of the company’s stock, of which one-third .

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2024
Fair Value Measurements
Fair Value Measurements	Note 7. Fair Value Measurements Accounting standards provide a comprehensive framework for measuring fair value, 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. Note 7. Fair Value Measurements (Continued) The following table sets forth financial assets and liabilities measured at fair value on a recurring basis in the consolidated balance sheet and the respective levels to which the fair value measurements are classified within the fair value hierarchy as of December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Quoted Prices ​ Significant ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ in Active ​ Other ​ Significant ​ ​ ​ ​ ​ ​ ​ Markets for ​ Observable ​ Unobservable ​ ​ ​ ​ ​ ​ ​ Identical Assets ​ Inputs ​ Inputs ​ ​ ​ ​ Total ​ (Level 1) ​ (Level 2) ​ (Level 3) ​ ​ ​ December 31, 2024 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term investments $ 147,811 ​ $ - ​ $ 147,811 ​ $ - ​ ​ ​ Commodity futures – financial assets ​ 19,323 ​ ​ - ​ ​ 19,323 ​ ​ - ​ ​ ​ Commodity futures – financial liabilities ​ 6,272 ​ ​ - ​ ​ 6,272 ​ ​ - ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term investments $ 721,210 ​ $ - ​ $ 721,210 ​ $ - ​ ​ ​ Commodity futures – financial assets ​ 2,483 ​ ​ - ​ ​ 2,483 ​ ​ - ​ ​ ​ Commodity futures – financial liabilities ​ 9,305 ​ ​ - ​ ​ 9,305 ​ ​ - ​ ​ ​ The carrying amounts of financial instruments including cash equivalents approximate fair value (Level 1). The fair values of short-term investments 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 (Level 2). The fair value of long-term debt, including current maturities, as determined by quoted market prices (Level 2), was approximately $3.0 billion and $2.8 billion at December 31, 2024 and 2023, respectively (with a corresponding carrying amount in the consolidated balance sheet of $3.2 billion and $3.1 billion at December 31, 2024 and 2023, respectively).

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2024
Commitments and Contingencies
Commitments and Contingencies	Note 8. Commitments and Contingencies The company has entered into certain commitments with suppliers which are of a customary nature. Commitments have been entered into relating to future expected requirements for commodities such as electricity, water, natural gas and its transportation services, fuel, air products, zinc, and electrodes. Certain commitments contain provisions which require that the company “take or pay” for specified quantities at fixed prices without regard to actual usage for periods of generally up to 5 years for physical commodity requirements and commodity transportation requirements, with some extending beyond, and for up to 15 years for air products and 27 years for water products. The company utilized such “take or pay” requirements during the past three years under these contracts. The company believes that production requirements will be such that consumption of the products or services purchased under these commitments will occur in the normal production process. The company’s commitments for these agreements with “take or pay” or other similar commitment provisions for the years ending December 31 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ 2025 ​ $ 358,976 ​ ​ 2026 ​ ​ 57,430 ​ ​ 2027 ​ ​ 37,483 ​ ​ 2028 ​ ​ 24,360 ​ ​ 2029 ​ ​ 18,698 ​ ​ Thereafter ​ ​ 164,532 ​ ​ ​ ​ $ 661,479 ​ ​ ​ Note 8. Commitments and Contingencies (Continued) At December 31, 2024, the company has outstanding commitments of $578.8 million related to ongoing construction of property, plant, and equipment, most significantly the recycled aluminum flat rolled products mill and recycled aluminum slab facilities, as well as other steel operations expansion projects in 2025. The company’s commitments for operating leases are discussed in Note 11. Leases. The company is involved in various litigation matters, including administrative and regulatory proceedings, that arise in the ordinary course of business, none of which are expected to have a material impact on the company’s financial condition, results of operations, or liquidity.

Transactions with Affiliated Co

Transactions with Affiliated Companies	12 Months Ended
	Dec. 31, 2024
Transactions with Affiliated Companies
Transactions with Affiliated Companies	Note 9. Transactions with Affiliated Companies The company purchases and sells recycled and scrap metal, steel, and purchases transportation services with other smaller affiliated companies, including equity method investments. These transactions for the years ended December 31, are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ 2022 ​ ​ Sales $ 720,742 ​ $ 680,004 ​ $ 791,523 ​ ​ Accounts receivable ​ 54,230 ​ ​ 73,245 ​ ​ 79,769 ​ ​ Purchases ​ 188,906 ​ ​ 167,798 ​ ​ 127,860 ​ ​ Accounts payable ​ 7,267 ​ ​ 9,685 ​ ​ 9,934 ​ ​

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2024
Retirement Plans
Retirement Plans	Note 10. Retirement Plans The company sponsors several 401(k) retirement savings and profit sharing plans (Plans) for eligible employees, which are considered “qualified plans” for federal income tax purposes. The company’s total expense for the Plans was $209.0 million, $312.4 million, and $466.9 million for the years ended December 31, 2024, 2023, and 2022, respectively. Profit sharing expense for eligible employees is 8% of consolidated pretax income excluding noncontrolling interests and other items. The resulting profit sharing expense under the Plan was $165.2 million, $264.6 million, and $421.6 million for the years ended December 31, 2024, 2023, and 2022, respectively; of which up to $132.2 million, $211.6 million, and $337.2 million, respectively, was directed by the company’s board of directors to be contributed to the Plans (subject to total Plan contribution limitations), with the remaining amounts each year paid directly in cash to the Plans’ participants.

Leases

Leases	12 Months Ended
	Dec. 31, 2024
Leases
Leases	Note 11. Leases The company has operating leases relating principally to transportation and other equipment, and some real estate. The company determines if an arrangement contains a lease at inception, which generally occurs when the arrangement identifies a specific asset that the company has the right to direct the use of and obtain substantially all of the economic benefit from use of the identified asset. Certain of the lease agreements contain rent escalation clauses (including fixed and index-based escalations), and options to extend or terminate the lease. For purposes of calculating operating lease obligations, the company’s lease terms include options to extend the lease when it is reasonably certain that the company will exercise such option. The company uses its incremental borrowing rate at lease commencement to determine the present value of lease payments. The incremental borrowing rate is the rate of interest the company could borrow on a collateralized basis over a similar term with similar payments. Operating lease expense is recognized on a straight-line basis over the lease term. ​ Note 11. Leases (Continued) Operating lease right-of-use assets and lease obligations included in the consolidated balance sheets at December 31, are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ ​ 2023 ​ Right-of-use assets under operating leases: ​ ​ ​ ​ ​ ​ Other assets - noncurrent $ 113,500 ​ $ 127,499 ​ Lease obligations under operating leases: ​ ​ ​ ​ ​ ​ Accrued liabilities $ 19,915 ​ $ 21,003 ​ Other liabilities - noncurrent ​ 94,417 ​ ​ 107,147 ​ ​ $ 114,332 ​ $ 128,150 ​ The weighted average remaining lease term for our operating leases is nine years as of December 31, 2024 and 2023. The weighted-average discount rate is 4.46% and 4.31% as of December 31, 2024 and 2023, respectively. Future operating lease liabilities as of December 31, 2024, for the next five years and thereafter are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2025 $ 24,207 ​ ​ ​ ​ 2026 ​ 19,315 ​ ​ ​ ​ 2027 ​ 16,411 ​ ​ ​ ​ 2028 ​ 13,673 ​ ​ ​ ​ 2029 ​ 10,885 ​ ​ ​ ​ Thereafter ​ 54,126 ​ ​ ​ ​ Total undiscounted cash flows ​ 138,617 ​ ​ ​ ​ Less imputed interest ​ (24,285) ​ ​ ​ ​ Lease obligations under operating leases $ 114,332 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating lease expense included in the consolidated statements of income was $27.4 million, $27.9 million, and $23.7 million for the years ended December 31, 2024, 2023, and 2022, respectively. Cash paid related to operating lease obligations was $23.2 million, $22.8 million, and $20.1 million for the years ended December 31, 2024, 2023, and 2022, respectively. Variable lease costs were not material for the years ended December 31, 2024, 2023, and 2022. Short-term lease expense included in the consolidated statements of income was $51.3 million, $40.4 million, and $35.8 million for the years ended December 31, 2024, 2023, and 2022, respectively. Right-of-use assets obtained in exchange for new operating lease liabilities for the years ended December 31, 2024, 2023, and 2022 were $12.8 million, $38.8 million, and $30.9 million with addition of $16.8 million related to ROCA, respectively.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2024
Segment Information
Segment Information	​ ​ Note 12. Segment Information The company’s chief operating decision maker (CODM), who is the Chief Executive Officer, analyzes the results of the business through the following reportable segments: steel operations, metals recycling operations, steel fabrication operations, and aluminum operations. In the fourth quarter 2024, results from an entity previously reported within the metals recycling operations segment were moved to the aluminum operations segment, consistent with a change in how the CODM manages the business. Segment information provided within this Form 10-K has been recast for all prior periods presented consistent with the current reportable segment presentation. The segment operations are more fully described in Note 1. Description of the Business and Summary of Significant Accounting Policies The CODM assesses segment performance and allocates resources primarily based on operating income. The CODM uses operating income to allocate operating and capital resources and assesses performance of each segment by comparing actual operating income results to historical and previously forecasted financial information. The accounting policies of the reportable segments are consistent with those described in Note 1 to the consolidated financial statements. Intra-segment sales and any related profits are eliminated in consolidation. The company’s segment results, with prior periods recast consistent with our current reportable segments presentation, including disaggregated revenue by segment to external, external non-United States, and other segment customers, are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Metals ​ Steel ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended ​ Steel ​ Recycling ​ Fabrication ​ Aluminum ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2024 ​ Operations ​ Operations ​ Operations ​ Operations ​ Other (a) ​ Eliminations ​ Consolidated ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net sales - disaggregated revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ External ​ $ 11,311,552 ​ $ 1,311,124 ​ $ 1,761,771 ​ $ 256,051 ​ $ 1,435,062 ​ $ - ​ $ 16,075,560 External Non-United States ​ ​ 749,932 ​ ​ 694,010 ​ ​ 1,731 ​ ​ 2,496 ​ ​ 16,661 ​ ​ - ​ ​ 1,464,830 Other segments ​ ​ 465,582 ​ ​ 2,131,779 ​ ​ 8,293 ​ ​ 60,142 ​ ​ - ​ ​ (2,665,796) ​ ​ - Net sales ​ ​ 12,527,066 ​ ​ 4,136,913 ​ ​ 1,771,795 ​ ​ 318,689 ​ ​ 1,451,723 ​ ​ (2,665,796) ​ ​ 17,540,390 Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of goods sold ​ ​ 10,736,557 ​ ​ 3,946,457 ​ ​ 1,006,211 ​ ​ 298,572 ​ ​ 1,420,978 ​ ​ (2,670,971) ​ ​ 14,737,804 Other segment items (b) ​ ​ 208,135 ​ ​ 113,649 ​ ​ 98,600 ​ ​ 92,448 ​ ​ 348,153 ​ ​ (1,436) ​ ​ 859,549 Operating income (loss) ​ ​ 1,582,374 ​ ​ 76,807 ​ ​ 666,984 ​ ​ (72,331) ​ ​ (317,408) ​ ​ 6,611 ​ ​ 1,943,037 Interest expense, net of capitalized interest ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 56,347 Other (income) expense, net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (96,191) Income before income taxes ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 1,982,881 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and amortization ​ $ 351,558 ​ $ 56,148 ​ $ 11,071 ​ $ 6,786 ​ $ 53,344 ​ $ - ​ $ 478,907 Capital expenditures ​ ​ 461,524 ​ ​ 83,020 ​ ​ 29,374 ​ ​ 1,309,027 ​ ​ 55,183 ​ ​ (70,122) ​ ​ 1,868,006 Total Assets ​ ​ 8,776,445 ​ ​ 1,301,234 ​ ​ 665,867 ​ ​ 2,802,647 ​ ​ 3,319,917 (c) ​ (1,930,877) ​ ​ 14,935,233 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Note 12. Segment Information (Continued) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Metals ​ Steel ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended ​ Steel ​ Recycling ​ Fabrication ​ Aluminum ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ Operations ​ Operations ​ Operations ​ Operations ​ Other (a) ​ Eliminations ​ Consolidated ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net sales - disaggregated revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ External ​ $ 11,603,139 ​ $ 1,162,246 ​ $ 2,798,262 ​ $ 239,095 ​ $ 1,164,942 ​ $ - ​ $ 16,967,684 External Non-United States ​ ​ 1,037,412 ​ ​ 774,211 ​ ​ 672 ​ ​ 9,105 ​ ​ 6,232 ​ ​ - ​ ​ 1,827,632 Other segments ​ ​ 427,071 ​ ​ 2,222,131 ​ ​ 7,843 ​ ​ 37,707 ​ ​ 727 ​ ​ (2,695,479) ​ ​ - Net sales ​ ​ 13,067,622 ​ ​ 4,158,588 ​ ​ 2,806,777 ​ ​ 285,907 ​ ​ 1,171,901 ​ ​ (2,695,479) ​ ​ 18,795,316 Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of goods sold ​ ​ 10,977,249 ​ ​ 3,971,743 ​ ​ 1,115,515 ​ ​ 237,759 ​ ​ 1,147,441 ​ ​ (2,700,274) ​ ​ 14,749,433 Other segment items (b) ​ ​ 208,773 ​ ​ 139,110 ​ ​ 98,001 ​ ​ 31,002 ​ ​ 419,037 ​ ​ (1,221) ​ ​ 894,702 Operating income (loss) ​ ​ 1,881,600 ​ ​ 47,735 ​ ​ 1,593,261 ​ ​ 17,146 ​ ​ (394,577) ​ ​ 6,016 ​ ​ 3,151,181 Interest expense, net of capitalized interest ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 76,484 Other (income) expense, net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (144,246) Income before income taxes ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 3,218,943 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and amortization ​ $ 331,225 ​ $ 65,803 ​ $ 9,787 ​ $ 4,917 ​ $ 26,072 ​ $ - ​ $ 437,804 Capital expenditures ​ ​ 453,955 ​ ​ 185,903 ​ ​ 22,044 ​ ​ 967,739 ​ ​ 28,264 ​ ​ - ​ ​ 1,657,905 Total Assets ​ ​ 8,650,450 ​ ​ 1,340,445 ​ ​ 790,399 ​ ​ 1,444,335 ​ ​ 3,248,822 (c) ​ (566,031) ​ ​ 14,908,420 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Metals ​ Steel ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended ​ Steel ​ Recycling ​ Fabrication ​ Aluminum ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ Operations ​ Operations ​ Operations ​ Operations ​ Other (a) ​ Eliminations ​ Consolidated ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net sales - disaggregated revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ External ​ $ 13,783,666 ​ $ 1,293,258 ​ $ 4,245,803 ​ $ 252,121 ​ $ 1,276,923 ​ $ - ​ $ 20,851,771 External Non-United States ​ ​ 779,683 ​ ​ 602,555 ​ ​ 183 ​ ​ 16,806 ​ ​ 9,776 ​ ​ - ​ ​ 1,409,003 Other segments ​ ​ 537,647 ​ ​ 2,304,414 ​ ​ 11,221 ​ ​ 23,158 ​ ​ 1,281 ​ ​ (2,877,721) ​ ​ - Net sales ​ ​ 15,100,996 ​ ​ 4,200,227 ​ ​ 4,257,207 ​ ​ 292,085 ​ ​ 1,287,980 ​ ​ (2,877,721) ​ ​ 22,260,774 Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of goods sold ​ ​ 11,787,382 ​ ​ 3,986,236 ​ ​ 1,737,366 ​ ​ 266,950 ​ ​ 1,295,721 ​ ​ (2,930,712) ​ ​ 16,142,943 Other segment items (b) ​ ​ 220,925 ​ ​ 114,619 ​ ​ 95,186 ​ ​ 10,365 ​ ​ 586,304 ​ ​ (1,390) ​ ​ 1,026,009 Operating income (loss) ​ ​ 3,092,689 ​ ​ 99,372 ​ ​ 2,424,655 ​ ​ 14,770 ​ ​ (594,045) ​ ​ 54,381 ​ ​ 5,091,822 Interest expense, net of capitalized interest ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 91,538 Other (income) expense, net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (20,785) Income before income taxes ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 5,021,069 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and amortization ​ $ 295,468 ​ $ 48,851 ​ $ 9,727 ​ $ 5,127 ​ $ 25,029 ​ $ - ​ $ 384,202 Capital expenditures ​ ​ 613,678 ​ ​ 63,967 ​ ​ 17,519 ​ ​ 189,805 ​ ​ 23,933 ​ ​ - ​ ​ 908,902 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (a) ​ (b) ​ (c)

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ 1,537,134	$ 2,450,882	$ 3,862,674

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Modified	false
Rule 10b5-1 Arrangement Modified	false

Insider Trading Policies and Pr

Insider Trading Policies and Procedures	12 Months Ended
	Dec. 31, 2024
Insider Trading Policies and Procedures [Line Items]
Insider Trading Policies and Procedures Adopted	true

Cybersecurity Risk Management a

Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
	Dec. 31, 2024
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	​ We recognize the importance of assessing, identifying, and managing material risks associated with cybersecurity third party vulnerability scans, third party penetration tests, and engagement of third parties to conduct analysis of our information security programs, including an overall assessment utilizing the NIST standards. ​ Our Director of Information Security is responsible for leading the Information Security Team which has established a cybersecurity risk management program of policies and processes for assessing, identifying, and managing risk from cybersecurity threats. We have integrated these processes into our overall risk management systems and processes, and routinely assess risks from cybersecurity threats, including any potential unauthorized access to or activity conducted through our information systems that may result in material adverse effects on the confidentiality, integrity, or availability of our information systems or any information residing therein. This program includes established reasonable safeguards to minimize the identified risks; processes to reasonably address any identified gaps in existing safeguards; updates to existing safeguards as necessary; and monitoring the effectiveness of those safeguards. ​ Our safeguards include continuous network monitoring, complex passwords, team member training that reinforces our policies, standards, and practices , incident response capability reviews and exercises, and cybersecurity insurance and disaster recovery plans for the protection of our assets. ​ Our cybersecurity risk management program also assesses third party providers, such as vendors, suppliers, and other business partners. Cybersecurity risks are evaluated when determining the selection and oversight of applicable third party providers and potential risks when handling or processing our employee, business, or customer data. ​ Further, we have designated a member of our senior leadership team, our Chief Financial Officer, to oversee the management of the safeguards, cybersecurity risk assessment, and mitigation process . From time to time, the Company’s program is reviewed and validated by internal and external experts. ​ In general, our incident response process follows the NIST framework and focuses on four phases: (i) preparation; (ii) detection and analysis; (iii) containment, eradication, and recovery; and (iv) post-incident remediation. As cybersecurity incidents occur, including at third party providers, the Director of Information Security leads the Information Security Team through a standardized incident response process that focuses on responding to and containing the threat, minimizing any business impact, and evaluating its severity level. The severity level assessment determines how widespread the incident is and to what degree it could impact our overall business and manufacturing environment. In the event an incident is determined by the ​ We do not believe that risks from cybersecurity threats, including as a result of any previous cybersecurity incidents, have materially affected or are reasonably likely to materially affect our overall business strategy, results of operations, or financial condition over the long term. In the last three years, the Company has not been aware of any material cybersecurity incidents occurring and we have not incurred material expenses from cybersecurity incidents (including penalties and settlements, of which there were none). For additional discussion of whether and how risks from cybersecurity threats could materially affect or are reasonably likely to materially affect the Company, see Item 1A. Risk Factors – “ We are subject to cybersecurity threats and may face risks to the security of our sensitive data and information technology which may adversely affect our business, results of operations, financial condition and cash flows.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	​ We recognize the importance of assessing, identifying, and managing material risks associated with cybersecurity third party vulnerability scans, third party penetration tests, and engagement of third parties to conduct analysis of our information security programs, including an overall assessment utilizing the NIST standards. ​ Our Director of Information Security is responsible for leading the Information Security Team which has established a cybersecurity risk management program of policies and processes for assessing, identifying, and managing risk from cybersecurity threats. We have integrated these processes into our overall risk management systems and processes, and routinely assess risks from cybersecurity threats, including any potential unauthorized access to or activity conducted through our information systems that may result in material adverse effects on the confidentiality, integrity, or availability of our information systems or any information residing therein. This program includes established reasonable safeguards to minimize the identified risks; processes to reasonably address any identified gaps in existing safeguards; updates to existing safeguards as necessary; and monitoring the effectiveness of those safeguards.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	One of the key functions of our Board of Directors is informed oversight of our risk management process, including risks from cybersecurity threats. Our Board of Directors is responsible for monitoring and assessing strategic risk exposure, and our senior leadership team is responsible for the day-to-day management of the material risks we face. Our Board of Directors administers its cybersecurity risk oversight function directly as a whole, as well as directly through the Audit Committee. regarding information security and an in-depth review of our processes for assessing, identifying, and managing material risks from cybersecurity threats. On a quarterly basis, the Audit Committee is informed by management concerning the status of existing and new cybersecurity risks, status of how management is addressing and mitigating those risks, cybersecurity and data privacy incidents (if any), and status of key information security initiatives. Additionally, on a biennial basis, we engage third parties to assess our information security program using the NIST framework, as well as perform penetration testing. ​ We have allocated substantial cross functional internal resources with expertise in information security, information technology, operations, risk management, human resources, finance, and legal to form a governance counsel known as the ISG. The ISG is an internal working group that collaborates with the
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	Our Board of Directors administers its cybersecurity risk oversight function directly as a whole, as well as directly through the Audit Committee.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	Management and members of the Information Security Group (“ISG”) regularly present to the Board of Directors regarding information security and an in-depth review of our processes for assessing, identifying, and managing material risks from cybersecurity threats. On a quarterly basis, the Audit Committee is informed by management concerning the status of existing and new cybersecurity risks, status of how management is addressing and mitigating those risks, cybersecurity and data privacy incidents (if any), and status of key information security initiatives. Additionally, on a biennial basis, we engage third parties to assess our information security program using the NIST framework, as well as perform penetration testing.
Cybersecurity Risk Role of Management [Text Block]	​ We have allocated substantial cross functional internal resources with expertise in information security, information technology, operations, risk management, human resources, finance, and legal to form a governance counsel known as the ISG. The ISG is an internal working group that collaborates with the
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	Information Security Group (“ISG”)
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	We have allocated substantial cross functional internal resources with expertise in information security, information technology, operations, risk management, human resources, finance, and legal to form a governance counsel known as the ISG. The ISG is an internal working group that collaborates with the
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	Management and members of the Information Security Group (“ISG”) regularly present to the Board of Directors regarding information security and an in-depth review of our processes for assessing, identifying, and managing material risks from cybersecurity threats. On a quarterly basis, the Audit Committee is informed by management concerning the status of existing and new cybersecurity risks, status of how management is addressing and mitigating those risks, cybersecurity and data privacy incidents (if any), and status of key information security initiatives. Additionally, on a biennial basis, we engage third parties to assess our information security program using the NIST framework, as well as perform penetration testing.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Description of the Business a_2

Description of the Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2024
Description of the Business and Summary of 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 intercompany accounts and transactions. Noncontrolling and redeemable noncontrolling interests represent the noncontrolling owners' proportionate share in the equity, income, or losses of the company’s majority-owned or controlled consolidated subsidiaries. Redeemable noncontrolling interests related to USS (owned 90% by SDI) are $60.0 million at December 31, 2024 and 2023. Redeemable noncontrolling interests related to Mesabi Nugget (owned 86% by SDI) are $111.2 million at December 31, 2024 and 2023.
Use of Estimates	Use of Estimates These consolidated 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 consolidated 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; allowances for credit losses 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 from Contracts with Customers	Revenue from Contracts with Customers In the steel, metals recycling, and aluminum operations segments, revenue is recognized at the point in time the performance obligation is satisfied, and control of the product is transferred to the customer upon shipment or delivery, at the amount of consideration the company expects to receive, including any variable consideration. The variable consideration included in the company’s steel operations segment contracts, which is not constrained, includes estimated product returns and customer claims based on historical experience, and may include volume rebates which are recorded on an expected value basis. Revenue recognized is limited to the amount the company expects to receive. The company does not exercise significant judgments in determining the timing of satisfaction of performance obligations or the transaction price. Shipment of products to customers is considered a fulfillment activity with amounts billed to customers included in sales and costs associated with such activities included in cost of goods sold. The company’s steel fabrication operations segment recognizes revenue over time at the amount of consideration the company expects to receive. Revenue is measured on an output method representing completed fabricated tons to date as a percentage of total tons required for each contract. Revenue from fabrication of tons remaining on partially fabricated customer contracts as of a reporting date, and future revenue from yet to be fabricated customer contracts, has not been disclosed under the practical expedient in Accounting Standards Codification (ASC) 606, Revenue from Contracts with Customers (ASC 606), paragraph ASC 606-10-50-14 related to customer contracts with expected duration of one year or less. The company does not exercise significant judgments in determining the timing of satisfaction of performance obligations or the transaction price. Shipment of products to customers, which occurs after control over the product has transferred to the customer and revenue is recognized, is considered a fulfillment activity with amounts billed to customers included in sales and costs associated with such activities included in cost of goods sold. Payments from customers are generally due within 30 days of invoicing, which generally occurs upon shipment of the products. Shipment for the steel fabrication operations segment generally occurs within 30 days of satisfaction of the performance obligation and revenue recognition. The company does not have financing components. Payments from customers have historically been within these terms, however, payments for non-U.S. sales may extend longer. Note 1. Description of the Business and Summary of Significant Accounting Policies (Continued) Refer to Note 12. Segment Information
Credit Losses	Credit Losses The company is exposed to credit risk in the event of nonpayment of accounts receivable by customers. The company mitigates its exposure to credit risk, which it generally extends 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. The allowance for credit losses for accounts receivable is based on the company’s reasonable estimate of known credit risks and historical experience, adjusted for current and anticipated economic and other pertinent factors affecting the company’s customers, that may differ from historical experience. Customer accounts receivable are written off when all collection efforts have been exhausted and the amounts are deemed uncollectible. At December 31, 2024 and 2023, the company reported $1,417.2 million and $1,608.3 million, respectively, of accounts receivable, net of allowances for credit losses of $7.7 million and $8.5 million, respectively. Changes in the allowance were not significant for the years ended December 31, 2024, 2023, or 2022.
Cash and Equivalents, and Restricted Cash	Cash and Equivalents, and Restricted Cash 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. The balance of cash, cash equivalents and restricted cash in the consolidated statements of cash flows includes restricted cash of
Short-Term Investments	Short-Term Investments Short-term investments include investments with maturity dates of longer than three months but less than one year when purchased. The company’s short-term investments are classified as trading securities. The short-term investments held as of December 31, 2024 consisted of commercial paper ($19.7 million), US Treasuries ($113.1 million), and certificates of deposit ($15.0 million). Short-term investments held as of December 31, 2023 consisted of commercial paper ($146.2 million), US Treasuries ($564.9 million), and certificates of deposit ($10.1 million). Interest income from invested cash and short-term investments was $90.1 million, $111.9 million, and $29.3 million for the years ended December 31, 2024, 2023, and 2022, respectively, and is recorded in other (income) expense, net as earned.
Inventories	Inventories Inventories are stated at lower of cost or net realizable value. Cost is determined using a weighted average cost method for raw materials (including scrap and purchased steel substrate) and supplies, and on a first-in, first-out basis for other inventory. Inventory consisted of the following at December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ ​ Raw materials $ 1,323,920 ​ $ 1,226,272 ​ ​ Supplies ​ 805,035 ​ ​ 711,653 ​ ​ Work in progress ​ 269,031 ​ ​ 296,932 ​ ​ Finished goods ​ 715,747 ​ ​ 659,775 ​ ​ Total inventories $ 3,113,733 ​ $ 2,894,632 ​
Property, Plant and Equipment	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, except for assets acquired in acquisitions which are valued at fair value at the purchase date. The company assigns each fixed asset a useful life ranging from 3 to 15 years for plant, machinery and equipment, and 5 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 steel operations segment assets, based on units produced, subject to minimum and maximum levels. Depreciation expense was $441.2 million, $397.0 million, and $349.4 million for the years ended December 31, 2024, 2023, and 2022, respectively. The company’s property, plant and equipment consisted of the following at December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ ​ Land and improvements ​ $ 801,210 ​ $ 693,166 ​ ​ Buildings and improvements ​ ​ 1,487,742 ​ ​ 1,255,274 ​ ​ Plant, machinery and equipment ​ ​ 7,666,513 ​ ​ 6,887,985 ​ ​ Construction in progress ​ ​ 2,767,013 ​ ​ 2,096,489 ​ ​ ​ ​ ​ 12,722,478 ​ ​ 10,932,914 ​ ​ Less accumulated depreciation ​ ​ 4,604,490 ​ ​ 4,198,696 ​ ​ Property, plant and equipment, net ​ $ 8,117,988 ​ $ 6,734,218 ​
Intangible Assets	Intangible Assets The company’s intangible assets consisted of the following at December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ ​ ​ ​ ​ Useful ​ Amortization ​ ​ ​ 2024 ​ 2023 ​ Life ​ Period ​ ​ Customer, vendor and scrap generator relationships $ 444,812 ​ $ 444,812 ​ 8 to 25 years ​ 22 years ​ ​ Trade names ​ 147,950 ​ ​ 147,950 ​ 15 to 25 years ​ 19 years ​ ​ Other ​ - ​ ​ 600 ​ ​ ​ ​ ​ ​ ​ ​ 592,762 ​ ​ 593,362 ​ ​ ​ 22 years ​ ​ Less accumulated amortization ​ 365,528 ​ ​ 335,603 ​ ​ ​ ​ ​ ​ ​ $ 227,234 ​ $ 257,759 ​ ​ ​ ​ ​ ​ The company utilizes an accelerated amortization methodology for customer, vendor and scrap generator relationships in order to follow the pattern in which the economic benefits of the amounts are anticipated to be consumed. Trade names are amortized using a straight-line methodology. Amortization of intangible assets was $30.5 million, $34.0 million, and $27.8 million for the years ended December 31, 2024, 2023, and 2022, respectively. ​ ​ Note 1. Description of the Business and Summary of Significant Accounting Policies (Continued) Estimated amortization expense related to amortizable intangibles for the years ending December 31 is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2025 ​ $ 27,464 ​ ​ 2026 ​ ​ 25,562 ​ ​ 2027 ​ ​ 23,163 ​ ​ 2028 ​ ​ 21,953 ​ ​ 2029 ​ ​ 19,583 ​ ​ Thereafter ​ ​ 109,509 ​ ​ Total ​ $ 227,234 ​
Impairment of Long-Lived Tangible and Definite Lived Intangible Assets	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 assets to its carrying amount. The company considers various factors and determines 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, the company’s strategy and capital planning, and the economic environment in markets to be served.
Goodwill	Goodwill The company’s goodwill consisted of the following at December 31, 2024 and 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Steel Operations Segment ​ $ 272,133 ​ ​ ​ Aluminum Operations Segment ​ ​ 14,000 ​ ​ ​ Metals Recycling Operations Segment ​ ​ 189,413 ​ ​ ​ Steel Fabrication Operations Segment ​ ​ 1,925 ​ ​ ​ ​ ​ $ 477,471 ​ ​ ​ In the fourth quarter 2024, results from an entity previously included in the metals recycling operations segment were moved to the aluminum operations segment, which also resulted in $14 million of goodwill
Impairment of Goodwill	Impairment of Goodwill At least once annually (as of October 1), or when indicators of impairment exist, the company performs a goodwill impairment analysis. Goodwill is allocated to various reporting units, which are generally one level below the company’s operating segments. If the fair value exceeds the carrying value of the reporting unit, there is no impairment. If the carrying amount exceeds the fair value, the company recognizes an impairment loss in the amount by which the carrying value of the net assets assigned to the reporting unit exceeds the fair value of the reporting unit, with the impairment loss not to exceed the amount of goodwill allocated to the reporting unit. The company has the option to consider qualitative factors to assess if it is more likely than not that the fair value of a reporting unit exceeds its carrying value. If elected to bypass the qualitative assessment or if indications of a potential impairment exist, the company performs a quantitative test. Note 1. Description of the Business and Summary of Significant Accounting Policies (Continued) When conducting a qualitative assessment, the company considers the impact of several factors on the company overall and each reporting unit individually including the timing and results of prior quantitative tests performed, changes in the carrying amount of the reporting unit, macroeconomic conditions (including changes in interest and discount rates), industry and market conditions, recent and projected financial performance, the company’s competitive position and other factors. When conducting a quantitative test, 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 for some years by using a market approach based upon an analysis of valuation metrics of comparable peer companies, using Level 3 fair value inputs as provided for under ASC 820, Fair Value Measurement . ​ No impairment was identified during the company’s 2024, 2023 or 2022 annual goodwill impairment analysis. During 2024, the company performed a qualitative assessment and performed quantitative tests in 2023 and 2022.
Equity-Based Compensation	Equity-Based Compensation The company has several stock-based employee compensation plans which are more fully described in Note 6. Equity-Based Incentive Plans. Compensation expense for restricted stock units, deferred stock units, restricted stock, stock appreciation awards, 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. The company recognizes forfeitures as they occur. Compensation expense for these stock-based employee compensation plans was $65.6 million, $60.1 million, and $69.2 million for the years ended December 31, 2024, 2023, and 2022, respectively.
Income Taxes	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	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 restricted stock units, deferred stock units, restricted stock, and performance awards, and are excluded from the computation in periods in which they have an anti-dilutive effect. There were 269,000 anti-dilutive common stock equivalents as of and for the year ended December 31, 2024. There were no anti-dilutive common stock equivalents as of and for the years ended December 31, 2023, and 2022. ​ Note 1. Description of the Business and Summary of Significant Accounting Policies (Continued) 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): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ ​ 2023 ​ ​ Net Income ​ Shares ​ Per Share ​ ​ Net Income ​ Shares ​ Per Share ​ ​ (Numerator) ​ (Denominator) ​ Amount ​ ​ (Numerator) ​ (Denominator) ​ Amount Basic earnings per share ​ $ 1,537,134 ​ ​ 155,420 ​ $ 9.89 ​ ​ $ 2,450,882 ​ ​ 166,552 ​ $ 14.72 Dilutive common share equivalents ​ ​ - ​ ​ 716 ​ ​ ​ ​ ​ ​ - ​ ​ 879 ​ ​ ​ Diluted earnings per share ​ $ 1,537,134 ​ ​ 156,136 ​ $ 9.84 ​ ​ $ 2,450,882 ​ ​ 167,431 ​ $ 14.64 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 ​ ​ Net Income ​ Shares ​ Per Share ​ ​ (Numerator) ​ (Denominator) ​ Amount ​ Basic earnings per share $ 3,862,674 ​ ​ 183,393 ​ $ 21.06 ​ Dilutive common share equivalents ​ - ​ ​ 1,229 ​ ​ ​ ​ Diluted earnings per share $ 3,862,674 ​ ​ 184,622 ​ $ 20.92 ​
Concentration of Credit Risk	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. When advantageous, the company places its temporary cash 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.
Derivative Financial Instruments	Derivative Financial Instruments The company routinely enters into forward exchange traded futures to manage price risk associated with nonferrous metal inventory, as well as purchases and sales of nonferrous (primarily aluminum and copper) and ferrous metals, to reduce exposure to commodity related price fluctuations. The company does not enter into these derivative financial instruments for speculative purposes. 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 for fair value hedges. 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 has derivative financial instruments in the form of forward contracts in various metallic commodities and those related to managing fluctuations in foreign exchange rates. 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 in earnings. Note 1. Description of the Business and Summary of Significant Accounting Policies (Continued) The fair value of the Company’s derivative instruments, along with required margin deposit amounts with the same counterparty under master netting arrangements, totaled $26.0 million and $24.0 million at December 31, 2024 and 2023, respectively, and are reflected in other current assets in the consolidated balance sheets. Total gains and losses related to derivatives in fair value hedging relationships, as well as those not designated as hedging instruments, are recognized in costs of goods sold and were insignificant for the years ended December 31, 2024, 2023, and 2022. Derivatives accounted for as cash flow hedges, for which gains and losses are recognized in other comprehensive income, along with net amounts reclassified from accumulated other comprehensive income, were insignificant for the years ended December 31, 2024, 2023, and 2022.
Recently Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements In November 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures Segment Information Recently Issued Not Yet Adopted Accounting Pronouncements In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures In November 2024, the FASB issued ASU 2024-03, Income Statement Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses

Description of the Business a_3

Description of the Business and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2024
Description of the Business and Summary of Significant Accounting Policies
Schedule of Inventories	Inventory consisted of the following at December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ ​ Raw materials $ 1,323,920 ​ $ 1,226,272 ​ ​ Supplies ​ 805,035 ​ ​ 711,653 ​ ​ Work in progress ​ 269,031 ​ ​ 296,932 ​ ​ Finished goods ​ 715,747 ​ ​ 659,775 ​ ​ Total inventories $ 3,113,733 ​ $ 2,894,632 ​
Schedule of Property, Plant and Equipment	The company’s property, plant and equipment consisted of the following at December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ ​ Land and improvements ​ $ 801,210 ​ $ 693,166 ​ ​ Buildings and improvements ​ ​ 1,487,742 ​ ​ 1,255,274 ​ ​ Plant, machinery and equipment ​ ​ 7,666,513 ​ ​ 6,887,985 ​ ​ Construction in progress ​ ​ 2,767,013 ​ ​ 2,096,489 ​ ​ ​ ​ ​ 12,722,478 ​ ​ 10,932,914 ​ ​ Less accumulated depreciation ​ ​ 4,604,490 ​ ​ 4,198,696 ​ ​ Property, plant and equipment, net ​ $ 8,117,988 ​ $ 6,734,218 ​
Schedule of Finite-Lived Intangible Assets	The company’s intangible assets consisted of the following at December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ ​ ​ ​ ​ Useful ​ Amortization ​ ​ ​ 2024 ​ 2023 ​ Life ​ Period ​ ​ Customer, vendor and scrap generator relationships $ 444,812 ​ $ 444,812 ​ 8 to 25 years ​ 22 years ​ ​ Trade names ​ 147,950 ​ ​ 147,950 ​ 15 to 25 years ​ 19 years ​ ​ Other ​ - ​ ​ 600 ​ ​ ​ ​ ​ ​ ​ ​ 592,762 ​ ​ 593,362 ​ ​ ​ 22 years ​ ​ Less accumulated amortization ​ 365,528 ​ ​ 335,603 ​ ​ ​ ​ ​ ​ ​ $ 227,234 ​ $ 257,759 ​ ​ ​ ​ ​
Schedule of Intangible Assets, Future Amortization Expense	Estimated amortization expense related to amortizable intangibles for the years ending December 31 is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2025 ​ $ 27,464 ​ ​ 2026 ​ ​ 25,562 ​ ​ 2027 ​ ​ 23,163 ​ ​ 2028 ​ ​ 21,953 ​ ​ 2029 ​ ​ 19,583 ​ ​ Thereafter ​ ​ 109,509 ​ ​ Total ​ $ 227,234 ​
Schedule of Goodwill	The company’s goodwill consisted of the following at December 31, 2024 and 2023 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Steel Operations Segment ​ $ 272,133 ​ ​ ​ Aluminum Operations Segment ​ ​ 14,000 ​ ​ ​ Metals Recycling Operations Segment ​ ​ 189,413 ​ ​ ​ Steel Fabrication Operations Segment ​ ​ 1,925 ​ ​ ​ ​ ​ $ 477,471 ​ ​
Reconciliation of 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 the years ended December 31 (in thousands, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ ​ 2023 ​ ​ Net Income ​ Shares ​ Per Share ​ ​ Net Income ​ Shares ​ Per Share ​ ​ (Numerator) ​ (Denominator) ​ Amount ​ ​ (Numerator) ​ (Denominator) ​ Amount Basic earnings per share ​ $ 1,537,134 ​ ​ 155,420 ​ $ 9.89 ​ ​ $ 2,450,882 ​ ​ 166,552 ​ $ 14.72 Dilutive common share equivalents ​ ​ - ​ ​ 716 ​ ​ ​ ​ ​ ​ - ​ ​ 879 ​ ​ ​ Diluted earnings per share ​ $ 1,537,134 ​ ​ 156,136 ​ $ 9.84 ​ ​ $ 2,450,882 ​ ​ 167,431 ​ $ 14.64 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 ​ ​ Net Income ​ Shares ​ Per Share ​ ​ (Numerator) ​ (Denominator) ​ Amount ​ Basic earnings per share $ 3,862,674 ​ ​ 183,393 ​ $ 21.06 ​ Dilutive common share equivalents ​ - ​ ​ 1,229 ​ ​ ​ ​ Diluted earnings per share $ 3,862,674 ​ ​ 184,622 ​ $ 20.92 ​

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2024
Long-Term Debt.
Schedule of Long-term Debt Instruments	The company’s borrowings consisted of the following at December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ ​ ​ ​ 2.800% senior notes due 2024 $ - ​ $ 400,000 ​ ​ ​ ​ 2.400% senior notes due 2025 ​ 400,000 ​ ​ 400,000 ​ ​ ​ ​ 5.000% senior notes due 2026 ​ 400,000 ​ ​ 400,000 ​ ​ ​ ​ 1.650% senior notes due 2027 ​ 350,000 ​ ​ 350,000 ​ ​ ​ ​ 3.450% senior notes due 2030 ​ 600,000 ​ ​ 600,000 ​ ​ ​ ​ 3.250% senior notes due 2031 ​ 500,000 ​ ​ 500,000 ​ ​ ​ ​ 5.375% senior notes due 2034 ​ 600,000 ​ ​ - ​ ​ ​ ​ 3.250% senior notes due 2050 ​ 400,000 ​ ​ 400,000 ​ ​ ​ ​ Other obligations ​ 28,803 ​ ​ 61,836 ​ ​ ​ ​ Total debt ​ 3,278,803 ​ ​ 3,111,836 ​ ​ ​ ​ Less debt issuance costs and original issue discounts ​ 47,796 ​ ​ 40,780 ​ ​ ​ ​ Total amounts outstanding ​ 3,231,007 ​ ​ 3,071,056 ​ ​ ​ ​ Less current maturities ​ 426,990 ​ ​ 459,987 ​ ​ ​ ​ Long-term debt $ 2,804,017 ​ $ 2,611,069 ​ ​
Schedule of Maturities of Long-term Debt	Maturities of outstanding debt as of December 31, 2024, are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ 2025 ​ $ 427,442 ​ ​ 2026 ​ ​ 400,896 ​ ​ 2027 ​ ​ 350,465 ​ ​ 2028 ​ ​ - ​ ​ 2029 ​ ​ - ​ ​ Thereafter ​ ​ 2,100,000 ​ ​ ​ ​ $ 3,278,803 ​

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2024
Income Taxes
Schedule of components of earnings before income taxes and noncontrolling interests	Components of earnings before income taxes and noncontrolling interests for the years ended December 31 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ 2022 ​ ​ United States income $ 1,992,814 ​ $ 3,198,048 ​ $ 4,996,762 ​ ​ Foreign income (loss) ​ (9,933) ​ ​ 20,895 ​ ​ 24,307 ​ ​ Total income before income taxes $ 1,982,881 ​ $ 3,218,943 ​ $ 5,021,069 ​
Schedule of Components of Income Tax Expense (Benefit)	The company files a consolidated federal income tax return. The provision for income tax expense for the years ended December 31 is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ 2022 ​ ​ Current income tax expense ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal $ 409,586 ​ $ 600,499 ​ $ 946,016 ​ ​ State ​ 57,942 ​ ​ 91,965 ​ ​ 152,758 ​ ​ Foreign ​ 7,980 ​ ​ 3,482 ​ ​ 8,605 ​ ​ Total current ​ 475,508 ​ ​ 695,946 ​ ​ 1,107,379 ​ ​ Deferred income tax expense (benefit) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ (26,311) ​ ​ 38,172 ​ ​ 22,168 ​ ​ State ​ (12,476) ​ ​ 15,355 ​ ​ 13,333 ​ ​ Foreign ​ (3,796) ​ ​ 2,138 ​ ​ (1,303) ​ ​ Total deferred ​ (42,583) ​ ​ 55,665 ​ ​ 34,198 ​ ​ Total income tax expense $ 432,925 ​ $ 751,611 ​ $ 1,141,577 ​
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of the statutory rates to the actual effective tax rates for the years ended December 31 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ 2022 ​ ​ Statutory federal tax rate ​ 21.0 % ​ ​ 21.0 % ​ ​ 21.0 % ​ ​ State income taxes, net of federal benefit ​ 1.8 ​ ​ ​ 2.6 ​ ​ ​ 2.6 ​ ​ ​ Federal research & development credits ​ (0.9) ​ ​ ​ (0.2) ​ ​ ​ (0.6) ​ ​ ​ Other permanent differences ​ (0.1) ​ ​ ​ (0.1) ​ ​ ​ (0.3) ​ ​ ​ Effective tax rate ​ 21.8 % ​ ​ 23.3 % ​ ​ 22.7 % ​ ​
Schedule of Deferred Tax Assets and Liabilities	Significant components of the company’s deferred tax assets and liabilities at December 31 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ ​ Deferred tax assets ​ ​ ​ ​ ​ ​ ​ Accrued expenses and allowances $ 41,031 ​ $ 41,894 ​ ​ Inventories ​ 6,892 ​ ​ 10,685 ​ ​ Net operating loss carryforwards ​ 24,381 ​ ​ 7,663 ​ ​ Amortizable assets ​ 39,657 ​ ​ 5,798 ​ ​ Other ​ 5,916 ​ ​ 9,149 ​ ​ ​ ​ 117,877 ​ ​ 75,189 ​ ​ Less: valuation allowance ​ (1,150) ​ ​ (816) ​ ​ Total net deferred tax assets ​ 116,727 ​ ​ 74,373 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax liabilities ​ ​ ​ ​ ​ ​ ​ Property, plant and equipment ​ (1,014,515) ​ ​ (1,013,045) ​ ​ Other ​ (4,398) ​ ​ (6,096) ​ ​ Total deferred tax liabilities ​ (1,018,913) ​ ​ (1,019,141) ​ ​ Net deferred tax liability $ (902,186) ​ $ (944,768) ​
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ 2022 ​ ​ Balance at January 1 $ 31,258 ​ $ 28,646 ​ $ 20,466 ​ ​ Increases related to current year tax positions ​ 5,115 ​ ​ 1,500 ​ ​ 9,600 ​ ​ Increases related to prior year tax positions ​ 263 ​ ​ 1,798 ​ ​ 364 ​ ​ Decreases related to prior year tax positions ​ (6,949) ​ ​ (686) ​ ​ (1,784) ​ ​ Balance at December 31 $ 29,687 ​ $ 31,258 ​ $ 28,646 ​

Equity-Based Incentive Plans (T

Equity-Based Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2024
Equity-Based Incentive Plans
Schedule of Restricted Stock Units Award Activity	A summary of the company’s RSU activity and outstanding RSUs as of December 31, 2024, are presented below (dollars in thousands except grant date fair value): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Aggregate ​ ​ ​ ​ Number ​ Average Grant ​ Intrinsic ​ Unrecognized ​ of RSUs ​ Date Fair Value ​ Value ​ Compensation Outstanding RSUs as of January 1, 2022 1,348,258 ​ $ 43.82 ​ $ 83,686 ​ $ 39,657 Granted 481,926 ​ ​ 98.29 ​ ​ ​ ​ ​ ​ Vested (786,622) ​ ​ 37.38 ​ ​ ​ ​ ​ ​ Forfeited (70,011) ​ ​ 46.82 ​ ​ ​ ​ ​ ​ As of December 31, 2022 973,551 ​ $ 71.80 ​ $ 94,765 ​ $ 44,394 Granted 433,810 ​ ​ 108.95 ​ ​ ​ ​ ​ ​ Vested (517,041) ​ ​ 64.03 ​ ​ ​ ​ ​ ​ Forfeited (40,829) ​ ​ 78.70 ​ ​ ​ ​ ​ ​ As of December 31, 2023 849,491 ​ $ 99.13 ​ $ 101,480 ​ $ 43,073 Granted 374,370 ​ ​ 137.14 ​ ​ ​ ​ ​ ​ Vested (394,675) ​ ​ 94.28 ​ ​ ​ ​ ​ ​ Forfeited (39,874) ​ ​ 104.21 ​ ​ ​ ​ ​ ​ As of December 31, 2024 (nonvested) 789,312 ​ $ 115.47 ​ $ 90,037 ​ $ 54,964
Schedule of Performance Period Transition Awards	The Compensation Committee granted the following three-year performance period awards and transition awards, which have been earned and have or will be issued as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maximum ​ ​ ​ ​ ​ ​ ​ ​ Shares That ​ Award ​ ​ ​ ​ ​ ​ Could Be Issued ​ Earned ​ Award Issued/Issuable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2021 LTIP Award: ​ ​ ​ ​ ​ ​ ​ ​ Three-year performance period award 360,189 ​ 324,173 ​ 324,173 ​ March 2024 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2022 LTIP Award: ​ ​ ​ ​ ​ ​ ​ ​ Three-year performance period award 249,759 ​ 249,759 ​ 249,759 ​ March 2025 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 LTIP Award: ​ ​ ​ ​ ​ ​ ​ ​ Three-year performance period award 193,946 ​ * ​ * ​ ​ ​ Two-year performance period transition award 5,517 ​ 4,690 ​ 4,690 ​ March 2025 ​ One-year performance period transition award 3,678 ​ 2,759 ​ 2,759 ​ March 2024 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 LTIP Award: ​ ​ ​ ​ ​ ​ ​ ​ Three-year performance period award 172,425 ​ * ​ * ​ ​ * Not yet earned as performance period not complete.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2024
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 on a recurring basis in the consolidated balance sheet and the respective levels to which the fair value measurements are classified within the fair value hierarchy as of December 31 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Quoted Prices ​ Significant ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ in Active ​ Other ​ Significant ​ ​ ​ ​ ​ ​ ​ Markets for ​ Observable ​ Unobservable ​ ​ ​ ​ ​ ​ ​ Identical Assets ​ Inputs ​ Inputs ​ ​ ​ ​ Total ​ (Level 1) ​ (Level 2) ​ (Level 3) ​ ​ ​ December 31, 2024 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term investments $ 147,811 ​ $ - ​ $ 147,811 ​ $ - ​ ​ ​ Commodity futures – financial assets ​ 19,323 ​ ​ - ​ ​ 19,323 ​ ​ - ​ ​ ​ Commodity futures – financial liabilities ​ 6,272 ​ ​ - ​ ​ 6,272 ​ ​ - ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Short-term investments $ 721,210 ​ $ - ​ $ 721,210 ​ $ - ​ ​ ​ Commodity futures – financial assets ​ 2,483 ​ ​ - ​ ​ 2,483 ​ ​ - ​ ​ ​ Commodity futures – financial liabilities ​ 9,305 ​ ​ - ​ ​ 9,305 ​ ​ - ​ ​

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2024
Commitments and Contingencies
Schedule of Unconditional Purchase Obligations	The company’s commitments for these agreements with “take or pay” or other similar commitment provisions for the years ending December 31 are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ 2025 ​ $ 358,976 ​ ​ 2026 ​ ​ 57,430 ​ ​ 2027 ​ ​ 37,483 ​ ​ 2028 ​ ​ 24,360 ​ ​ 2029 ​ ​ 18,698 ​ ​ Thereafter ​ ​ 164,532 ​ ​ ​ ​ $ 661,479 ​ ​

Transactions with Affiliated _2

Transactions with Affiliated Companies (Tables)	12 Months Ended
	Dec. 31, 2024
Transactions with Affiliated Companies
Schedule of Related Party Transactions	The company purchases and sells recycled and scrap metal, steel, and purchases transportation services with other smaller affiliated companies, including equity method investments. These transactions for the years ended December 31, are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ 2022 ​ ​ Sales $ 720,742 ​ $ 680,004 ​ $ 791,523 ​ ​ Accounts receivable ​ 54,230 ​ ​ 73,245 ​ ​ 79,769 ​ ​ Purchases ​ 188,906 ​ ​ 167,798 ​ ​ 127,860 ​ ​ Accounts payable ​ 7,267 ​ ​ 9,685 ​ ​ 9,934 ​ ​

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2024
Leases
Schedule of operating lease right-of-use assets and lease obligations	Operating lease right-of-use assets and lease obligations included in the consolidated balance sheets at December 31, are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ ​ 2023 ​ Right-of-use assets under operating leases: ​ ​ ​ ​ ​ ​ Other assets - noncurrent $ 113,500 ​ $ 127,499 ​ Lease obligations under operating leases: ​ ​ ​ ​ ​ ​ Accrued liabilities $ 19,915 ​ $ 21,003 ​ Other liabilities - noncurrent ​ 94,417 ​ ​ 107,147 ​ ​ $ 114,332 ​ $ 128,150
Schedule of future operating lease liabilities	Future operating lease liabilities as of December 31, 2024, for the next five years and thereafter are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2025 $ 24,207 ​ ​ ​ ​ 2026 ​ 19,315 ​ ​ ​ ​ 2027 ​ 16,411 ​ ​ ​ ​ 2028 ​ 13,673 ​ ​ ​ ​ 2029 ​ 10,885 ​ ​ ​ ​ Thereafter ​ 54,126 ​ ​ ​ ​ Total undiscounted cash flows ​ 138,617 ​ ​ ​ ​ Less imputed interest ​ (24,285) ​ ​ ​ ​ Lease obligations under operating leases $ 114,332 ​ ​ ​ ​ ​ ​ ​ ​ ​

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2024
Segment Information
Schedule of Operating Segment Results	The company’s segment results, with prior periods recast consistent with our current reportable segments presentation, including disaggregated revenue by segment to external, external non-United States, and other segment customers, are as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Metals ​ Steel ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended ​ Steel ​ Recycling ​ Fabrication ​ Aluminum ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2024 ​ Operations ​ Operations ​ Operations ​ Operations ​ Other (a) ​ Eliminations ​ Consolidated ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net sales - disaggregated revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ External ​ $ 11,311,552 ​ $ 1,311,124 ​ $ 1,761,771 ​ $ 256,051 ​ $ 1,435,062 ​ $ - ​ $ 16,075,560 External Non-United States ​ ​ 749,932 ​ ​ 694,010 ​ ​ 1,731 ​ ​ 2,496 ​ ​ 16,661 ​ ​ - ​ ​ 1,464,830 Other segments ​ ​ 465,582 ​ ​ 2,131,779 ​ ​ 8,293 ​ ​ 60,142 ​ ​ - ​ ​ (2,665,796) ​ ​ - Net sales ​ ​ 12,527,066 ​ ​ 4,136,913 ​ ​ 1,771,795 ​ ​ 318,689 ​ ​ 1,451,723 ​ ​ (2,665,796) ​ ​ 17,540,390 Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of goods sold ​ ​ 10,736,557 ​ ​ 3,946,457 ​ ​ 1,006,211 ​ ​ 298,572 ​ ​ 1,420,978 ​ ​ (2,670,971) ​ ​ 14,737,804 Other segment items (b) ​ ​ 208,135 ​ ​ 113,649 ​ ​ 98,600 ​ ​ 92,448 ​ ​ 348,153 ​ ​ (1,436) ​ ​ 859,549 Operating income (loss) ​ ​ 1,582,374 ​ ​ 76,807 ​ ​ 666,984 ​ ​ (72,331) ​ ​ (317,408) ​ ​ 6,611 ​ ​ 1,943,037 Interest expense, net of capitalized interest ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 56,347 Other (income) expense, net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (96,191) Income before income taxes ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 1,982,881 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and amortization ​ $ 351,558 ​ $ 56,148 ​ $ 11,071 ​ $ 6,786 ​ $ 53,344 ​ $ - ​ $ 478,907 Capital expenditures ​ ​ 461,524 ​ ​ 83,020 ​ ​ 29,374 ​ ​ 1,309,027 ​ ​ 55,183 ​ ​ (70,122) ​ ​ 1,868,006 Total Assets ​ ​ 8,776,445 ​ ​ 1,301,234 ​ ​ 665,867 ​ ​ 2,802,647 ​ ​ 3,319,917 (c) ​ (1,930,877) ​ ​ 14,935,233 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Metals ​ Steel ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended ​ Steel ​ Recycling ​ Fabrication ​ Aluminum ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ Operations ​ Operations ​ Operations ​ Operations ​ Other (a) ​ Eliminations ​ Consolidated ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net sales - disaggregated revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ External ​ $ 11,603,139 ​ $ 1,162,246 ​ $ 2,798,262 ​ $ 239,095 ​ $ 1,164,942 ​ $ - ​ $ 16,967,684 External Non-United States ​ ​ 1,037,412 ​ ​ 774,211 ​ ​ 672 ​ ​ 9,105 ​ ​ 6,232 ​ ​ - ​ ​ 1,827,632 Other segments ​ ​ 427,071 ​ ​ 2,222,131 ​ ​ 7,843 ​ ​ 37,707 ​ ​ 727 ​ ​ (2,695,479) ​ ​ - Net sales ​ ​ 13,067,622 ​ ​ 4,158,588 ​ ​ 2,806,777 ​ ​ 285,907 ​ ​ 1,171,901 ​ ​ (2,695,479) ​ ​ 18,795,316 Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of goods sold ​ ​ 10,977,249 ​ ​ 3,971,743 ​ ​ 1,115,515 ​ ​ 237,759 ​ ​ 1,147,441 ​ ​ (2,700,274) ​ ​ 14,749,433 Other segment items (b) ​ ​ 208,773 ​ ​ 139,110 ​ ​ 98,001 ​ ​ 31,002 ​ ​ 419,037 ​ ​ (1,221) ​ ​ 894,702 Operating income (loss) ​ ​ 1,881,600 ​ ​ 47,735 ​ ​ 1,593,261 ​ ​ 17,146 ​ ​ (394,577) ​ ​ 6,016 ​ ​ 3,151,181 Interest expense, net of capitalized interest ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 76,484 Other (income) expense, net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (144,246) Income before income taxes ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 3,218,943 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and amortization ​ $ 331,225 ​ $ 65,803 ​ $ 9,787 ​ $ 4,917 ​ $ 26,072 ​ $ - ​ $ 437,804 Capital expenditures ​ ​ 453,955 ​ ​ 185,903 ​ ​ 22,044 ​ ​ 967,739 ​ ​ 28,264 ​ ​ - ​ ​ 1,657,905 Total Assets ​ ​ 8,650,450 ​ ​ 1,340,445 ​ ​ 790,399 ​ ​ 1,444,335 ​ ​ 3,248,822 (c) ​ (566,031) ​ ​ 14,908,420 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Metals ​ Steel ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended ​ Steel ​ Recycling ​ Fabrication ​ Aluminum ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ Operations ​ Operations ​ Operations ​ Operations ​ Other (a) ​ Eliminations ​ Consolidated ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net sales - disaggregated revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ External ​ $ 13,783,666 ​ $ 1,293,258 ​ $ 4,245,803 ​ $ 252,121 ​ $ 1,276,923 ​ $ - ​ $ 20,851,771 External Non-United States ​ ​ 779,683 ​ ​ 602,555 ​ ​ 183 ​ ​ 16,806 ​ ​ 9,776 ​ ​ - ​ ​ 1,409,003 Other segments ​ ​ 537,647 ​ ​ 2,304,414 ​ ​ 11,221 ​ ​ 23,158 ​ ​ 1,281 ​ ​ (2,877,721) ​ ​ - Net sales ​ ​ 15,100,996 ​ ​ 4,200,227 ​ ​ 4,257,207 ​ ​ 292,085 ​ ​ 1,287,980 ​ ​ (2,877,721) ​ ​ 22,260,774 Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of goods sold ​ ​ 11,787,382 ​ ​ 3,986,236 ​ ​ 1,737,366 ​ ​ 266,950 ​ ​ 1,295,721 ​ ​ (2,930,712) ​ ​ 16,142,943 Other segment items (b) ​ ​ 220,925 ​ ​ 114,619 ​ ​ 95,186 ​ ​ 10,365 ​ ​ 586,304 ​ ​ (1,390) ​ ​ 1,026,009 Operating income (loss) ​ ​ 3,092,689 ​ ​ 99,372 ​ ​ 2,424,655 ​ ​ 14,770 ​ ​ (594,045) ​ ​ 54,381 ​ ​ 5,091,822 Interest expense, net of capitalized interest ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 91,538 Other (income) expense, net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (20,785) Income before income taxes ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 5,021,069 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Depreciation and amortization ​ $ 295,468 ​ $ 48,851 ​ $ 9,727 ​ $ 5,127 ​ $ 25,029 ​ $ - ​ $ 384,202 Capital expenditures ​ ​ 613,678 ​ ​ 63,967 ​ ​ 17,519 ​ ​ 189,805 ​ ​ 23,933 ​ ​ - ​ ​ 908,902 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (a) ​ (b) ​ (c)

Description of the Business a_4

Description of the Business and Summary of Significant Accounting Policies - Description of the Business (Details) $ in Thousands		12 Months Ended
	Apr. 01, 2023	Dec. 31, 2024 USD ($) state item segment	Dec. 31, 2023 USD ($)
Segment Reporting Information
Number of reportable segments | segment		4
Workforce represented by collective bargaining agreements (as a percent)		5%
Number of locations under collective bargaining arrangements | state		4
Percentage of workforce subject to collective bargaining arrangements expiring during the year		0.50%
Number of locations subject to collective bargaining agreements expiring | state		1
Redeemable noncontrolling interests		$ 171,212	$ 171,212
United Steel Supply, LLC
Segment Reporting Information
Noncontrolling interest, ownership percentage	90%	90%	90%
Redeemable noncontrolling interests		$ 60,000	$ 60,000
United Steel Supply, LLC | Steel Operations
Segment Reporting Information
Noncontrolling interest, ownership percentage	90%
SDI Biocarbon Solutions
Segment Reporting Information
Noncontrolling interest, ownership percentage		75%
Mesabi Nugget
Segment Reporting Information
Noncontrolling interest, ownership percentage		86%	86%
Redeemable noncontrolling interests		$ 111,200	$ 111,200
Unity Aluminum, Inc | Aluminum Operations
Segment Reporting Information
Number Of Satellite Recycled Aluminum Slab Centers | item		2
Noncontrolling interest, ownership percentage		94.40%

Description of the Business a_5

Description of the Business and Summary of Significant Accounting Policies - Credit Losses (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Description of the Business and Summary of Significant Accounting Policies
Accounts receivable, net	$ 1,417,200	$ 1,608,300
Allowance for credit losses	$ 7,728	$ 8,480

Description of the Business a_6

Description of the Business and Summary of Significant Accounting Policies - Cash and Equivalents, and Restricted Cash and Equivalents (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Description of the Business and Summary of Significant Accounting Policies
Restricted Cash and Cash Equivalents	$ 5.5	$ 5.6	$ 5.5	$ 5.5
Restricted Cash and Cash Equivalents, Asset, Statement of Financial Position [Extensible List]	Other assets	Other assets	Other assets	Other assets

Description of the Business a_7

Description of the Business and Summary of Significant Accounting Policies - Short-term Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Short Term Investments [Line Items]
Interest Income from invested cash and short-term investments	$ 90,100	$ 111,900	$ 29,300
Short-term investments	147,811	721,210
Commercial Paper
Short Term Investments [Line Items]
Short-term investments	19,700	146,200
US Treasury Securities
Short Term Investments [Line Items]
Short-term investments	113,100	564,900
Certificates of Deposit
Short Term Investments [Line Items]
Short-term investments	$ 15,000	$ 10,100

Description of the Business a_8

Description of the Business and Summary of Significant Accounting Policies - Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Description of the Business and Summary of Significant Accounting Policies
Raw materials	$ 1,323,920	$ 1,226,272
Supplies	805,035	711,653
Work in progress	269,031	296,932
Finished goods	715,747	659,775
Total inventories	$ 3,113,733	$ 2,894,632

Description of the Business a_9

Description of the Business and Summary of Significant Accounting Policies - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property, plant and equipment
Depreciation expense	$ 441,200	$ 397,000	$ 349,400
Property, plant and equipment, gross	12,722,478	10,932,914
Less accumulated depreciation	4,604,490	4,198,696
Property, plant and equipment, net	8,117,988	6,734,218
Land and improvements
Property, plant and equipment
Property, plant and equipment, gross	801,210	693,166
Buildings and improvements
Property, plant and equipment
Property, plant and equipment, gross	$ 1,487,742	1,255,274
Buildings and improvements | Minimum
Property, plant and equipment
Property, plant and equipment useful life	5 years
Buildings and improvements | Maximum
Property, plant and equipment
Property, plant and equipment useful life	40 years
Plant, machinery and equipment
Property, plant and equipment
Property, plant and equipment, gross	$ 7,666,513	6,887,985
Plant, machinery and equipment | Minimum
Property, plant and equipment
Property, plant and equipment useful life	3 years
Plant, machinery and equipment | Maximum
Property, plant and equipment
Property, plant and equipment useful life	15 years
Construction in progress
Property, plant and equipment
Property, plant and equipment, gross	$ 2,767,013	$ 2,096,489

Description of the Business _10

Description of the Business and Summary of Significant Accounting Policies - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 592,762	$ 593,362
Less accumulated amortization	365,528	335,603
Intangible Assets, Net (Excluding Goodwill), Total	227,234	257,759
Amortization of intangible assets	30,526	34,048	$ 27,837
Estimated amortization expense
2025	27,464
2026	25,562
2027	23,163
2028	21,953
2029	19,583
Thereafter	109,509
Total	$ 227,234
Weighted average
Finite-Lived Intangible Assets [Line Items]
Useful Life	22 years
Customer and scrap generator relationships
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 444,812	444,812
Customer and scrap generator relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful Life	8 years
Customer and scrap generator relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful Life	25 years
Customer and scrap generator relationships | Weighted average
Finite-Lived Intangible Assets [Line Items]
Useful Life	22 years
Trade names
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 147,950	147,950
Trade names | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful Life	15 years
Trade names | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful Life	25 years
Trade names | Weighted average
Finite-Lived Intangible Assets [Line Items]
Useful Life	19 years
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		$ 600

Description of the Business _11

Description of the Business and Summary of Significant Accounting Policies - Goodwill (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Goodwill
Goodwill	$ 477,471,000	$ 477,471,000
Goodwill impairment loss	0	0	$ 0
Compensation expense for stock-based employee compensation plan	65,600,000	60,100,000	$ 69,200,000
Steel Operations
Goodwill
Goodwill	272,133,000
Aluminum Operations
Goodwill
Goodwill	14,000,000
Aluminum Operations | Restatement Adjustment
Goodwill
Goodwill	14,000,000
Metals Recycling Operations
Goodwill
Goodwill	189,413,000
Metals Recycling Operations | Restatement Adjustment
Goodwill
Goodwill	(14,000,000)
Metals Recycling Operations | OmniSource
Goodwill
Goodwill impaired accumulated impairment loss	346,800,000	$ 346,800,000
Steel Fabrication Operations
Goodwill
Goodwill	$ 1,925,000

Description of the Business _12

Description of the Business and Summary of Significant Accounting Policies - Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share
Antidilutive common share equivalents excluded from computation of earnings per share amount (in shares)	269,000	0	0
Net Income (Numerator)
Basic earnings per share (in dollars)	$ 1,537,134	$ 2,450,882	$ 3,862,674
Diluted earnings per share (in dollars)	$ 1,537,134	$ 2,450,882	$ 3,862,674
Weighted Average Shares (Denominator)
Basic earnings per share (in shares)	155,420,000	166,552,000	183,393,000
Dilutive common share equivalents (in shares)	716,000	879,000	1,229,000
Diluted earnings per share (in shares)	156,136,000	167,431,000	184,622,000
Per Share Amount
Basic (in dollars per share)	$ 9.89	$ 14.72	$ 21.06
Diluted (in dollars per share)	$ 9.84	$ 14.64	$ 20.92

Description of the Business _13

Description of the Business and Summary of Significant Accounting Policies - Derivative Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Commodity contract | Futures
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Asset	$ 26	$ 24

Business Combinations and Inv_2

Business Combinations and Investments in Unconsolidated Affiliates (Details)		12 Months Ended
	Apr. 01, 2023	Dec. 31, 2024	Dec. 31, 2023	Oct. 01, 2022	Jul. 29, 2022	Apr. 01, 2022	Jan. 31, 2022	Mar. 01, 2019
United Steel Supply, LLC
Schedule of Equity Method Investments [Line Items]
Noncontrolling interest, ownership percentage	90%	90%	90%
New Process Steel LP
Schedule of Equity Method Investments [Line Items]
Equity interest acquired							45%
ROCA ACERO, S.A. de C.V.
Schedule of Equity Method Investments [Line Items]
Acquisition of interest (as a percent)				100%
Unity Aluminum, Inc
Schedule of Equity Method Investments [Line Items]
Acquisition of interest (as a percent)					94.40%
United Steel Supply, LLC
Schedule of Equity Method Investments [Line Items]
Acquisition of interest (as a percent)	2.50%					12.50%		75%
Percentage of voting equity interests remaining available	10%

Long-Term Debt - By Issue (Deta

Long-Term Debt - By Issue (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Jul. 31, 2024	Dec. 31, 2023
Senior Credit Facility
Total debt	$ 3,278,803		$ 3,111,836
Less debt issuance costs and original issue discounts	47,796		40,780
Long-term Debt, Total	3,231,007		3,071,056
Less current maturities	426,990		459,987
Long-term debt	$ 2,804,017		2,611,069
2.800% senior notes due 2024
Senior Credit Facility
Total debt			400,000
Stated interest rate	2.80%	2.80%
2.400% senior notes due 2025
Senior Credit Facility
Total debt	$ 400,000		400,000
Stated interest rate	2.40%
Senior Notes 5.000 Percent Due 2026
Senior Credit Facility
Total debt	$ 400,000		400,000
Stated interest rate	5%
1.650% senior notes due 2027
Senior Credit Facility
Total debt	$ 350,000		350,000
Stated interest rate	1.65%
3.450% senior notes due 2030
Senior Credit Facility
Total debt	$ 600,000		600,000
Stated interest rate	3.45%
3.250% senior notes due 2031
Senior Credit Facility
Total debt	$ 500,000		500,000
Stated interest rate	3.25%
5.375% senior notes due 2034
Senior Credit Facility
Total debt	$ 600,000
Stated interest rate	5.375%	5.375%
3.250% senior notes due 2050
Senior Credit Facility
Total debt	$ 400,000		400,000
Stated interest rate	3.25%
Other obligations
Senior Credit Facility
Total debt	$ 28,803		$ 61,836

Long-Term Debt - Financing Acti

Long-Term Debt - Financing Activity (Details) - USD ($) $ in Millions	Dec. 31, 2024	Jul. 31, 2024
5.375% senior notes due 2034
Senior Credit Facility
Debt issued	$ 600	$ 600
Stated interest rate	5.375%	5.375%
2.800% senior notes due 2024
Senior Credit Facility
Stated interest rate	2.80%	2.80%

Long-Term Debt - Senior Secured

Long-Term Debt - Senior Secured Credit Facility (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Jul. 19, 2023
Senior Credit Facility
Outstanding principal balance	$ 3,278,803	$ 3,111,836
Interest Coverage Ratio	21.68
Consolidated Leverage Ratio	0.27
Line of Credit [Member]
Senior Credit Facility
Maximum borrowing capacity of credit facility			$ 1,200,000
Additional amount by which facility size can be increased	$ 500,000
Availability on the senior secured revolver	1,200,000
Outstanding letters of credit and other obligations which reduce availability	9,300
Borrowings outstanding	$ 0
Line of Credit [Member] | Minimum [Member]
Senior Credit Facility
Interest rate added to the base rate (as a percent)	1%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	us-gaap:SecuredOvernightFinancingRateSofrMember
Unused commitment fee (as a percent)	0.11%
Consolidated interest coverage ratio	2.5
Line of Credit [Member] | Maximum [Member]
Senior Credit Facility
Interest rate added to the base rate (as a percent)	1.75%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	us-gaap:SecuredOvernightFinancingRateSofrMember
Unused commitment fee (as a percent)	0.275%
Leverage ratio	0.6

Long-Term Debt - Senior Unsecur

Long-Term Debt - Senior Unsecured Notes (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) loan	Jul. 31, 2024	Dec. 31, 2023 USD ($)
Senior Credit Facility
Long-Term Debt, Gross	$ 3,278,803		$ 3,111,836
Carrying amount	$ 3,231,007		3,071,056
Senior Notes [Member]
Senior Credit Facility
Debt Instrument, Number of Tranches | loan	7
2.800% senior notes due 2024
Senior Credit Facility
Long-Term Debt, Gross			400,000
Stated interest rate	2.80%	2.80%
2.400% senior notes due 2025
Senior Credit Facility
Long-Term Debt, Gross	$ 400,000		400,000
Stated interest rate	2.40%
Debt Instrument, Basis Spread on Variable Rate	0.35%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	us-gaap:UsTreasuryUstInterestRateMember
Redemption price of debt instrument (as a percent)	100%
Redemption start date	May 15, 2025
Senior Notes 5.000 Percent Due 2026
Senior Credit Facility
Long-Term Debt, Gross	$ 400,000		400,000
Stated interest rate	5%
Redemption price of debt instrument (as a percent)	100%
Redemption start date	Dec. 15, 2024
1.650% senior notes due 2027
Senior Credit Facility
Long-Term Debt, Gross	$ 350,000		350,000
Stated interest rate	1.65%
Debt Instrument, Basis Spread on Variable Rate	0.20%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	us-gaap:UsTreasuryUstInterestRateMember
Redemption price of debt instrument (as a percent)	100%
Redemption start date	Aug. 15, 2027
3.450% senior notes due 2030
Senior Credit Facility
Long-Term Debt, Gross	$ 600,000		600,000
Stated interest rate	3.45%
Debt Instrument, Basis Spread on Variable Rate	0.25%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	us-gaap:UsTreasuryUstInterestRateMember
Redemption price of debt instrument (as a percent)	100%
Redemption start date	Jan. 15, 2030
3.250% senior notes due 2031
Senior Credit Facility
Long-Term Debt, Gross	$ 500,000		500,000
Stated interest rate	3.25%
Debt Instrument, Basis Spread on Variable Rate	0.40%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	us-gaap:UsTreasuryUstInterestRateMember
Redemption price of debt instrument (as a percent)	100%
Redemption start date	Oct. 15, 2030
5.375% senior notes due 2034
Senior Credit Facility
Long-Term Debt, Gross	$ 600,000
Stated interest rate	5.375%	5.375%
Debt Instrument, Basis Spread on Variable Rate	0.20%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	us-gaap:UsTreasuryUstInterestRateMember
Redemption price of debt instrument (as a percent)	100%
Redemption start date	May 15, 2034
3.250% senior notes due 2050
Senior Credit Facility
Long-Term Debt, Gross	$ 400,000		$ 400,000
Stated interest rate	3.25%
Debt Instrument, Basis Spread on Variable Rate	0.30%
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	us-gaap:UsTreasuryUstInterestRateMember
Redemption price of debt instrument (as a percent)	100%
Redemption start date	Apr. 15, 2050

Long-Term Debt - Other Secured

Long-Term Debt - Other Secured Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Jul. 19, 2023
Senior Credit Facility
Outstanding principal balance	$ 3,278,803	$ 3,111,836
Senior secured revolving credit facility
Senior Credit Facility
Maximum borrowing capacity of credit facility			$ 1,200,000
Borrowings outstanding	0
Subsidiary One | Revolving Credit Facility
Senior Credit Facility
Maximum borrowing capacity of credit facility	$ 125,000
Line of Credit Facility, Interest Rate at Period End	6.40%
Borrowings outstanding	$ 26,400	59,800
Subsidiary Two | Revolving Credit Facility
Senior Credit Facility
Maximum borrowing capacity of credit facility	$ 30,000
Line of Credit Facility, Interest Rate at Period End	5.81%
Borrowings outstanding	$ 0	0
Subsidiary Three | Secured Debt
Senior Credit Facility
Long-Term Debt, Weighted Average Interest Rate, at Point in Time	4.34%
Outstanding principal balance	$ 2,400	$ 2,000

Long-Term Debt - Outstanding De

Long-Term Debt - Outstanding Debt Maturities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Maturities of outstanding debt
2025	$ 427,442
2026	400,896
2027	350,465
Thereafter	2,100,000
Total debt	3,278,803	$ 3,111,836
Interest costs
Interest costs incurred	123,100	109,500	$ 107,400
Interest costs incurred capitalized	$ 66,800	$ 33,000	$ 15,800

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Deferred Tax Assets, Valuation Allowance	$ 1,150,000	$ 816,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	26,400,000	27,800,000
Benefits (Expenses) from the decrease (increase) of interest expense	(710,000)	(1,560,000)	$ (480,000)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	4,200,000	$ 3,200,000
Minimum
Income Tax Examination, Estimate of Possible Loss	0
Maximum
Income Tax Examination, Estimate of Possible Loss	$ 12,000,000

Income Taxes - Schedule of comp

Income Taxes - Schedule of components of earnings before income taxes and noncontrolling interests (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Taxes
United States income	$ 1,992,814	$ 3,198,048	$ 4,996,762
Foreign income (loss)	(9,933)	20,895	24,307
Income before income taxes	$ 1,982,881	$ 3,218,943	$ 5,021,069

Income Taxes - Schedule of prov

Income Taxes - Schedule of provision for income tax expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Current income tax expense
Federal	$ 409,586	$ 600,499	$ 946,016
State	57,942	91,965	152,758
Foreign	7,980	3,482	8,605
Total current	475,508	695,946	1,107,379
Deferred income tax expense (benefit)
Federal	(26,311)	38,172	22,168
State	(12,476)	15,355	13,333
Foreign	(3,796)	2,138	(1,303)
Total deferred	(42,583)	55,665	34,198
Total income tax expense	$ 432,925	$ 751,611	$ 1,141,577

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Taxes
Statutory federal tax rate	21%	21%	21%
State income taxes, net of federal benefit	1.80%	2.60%	2.60%
Federal research & development credits	(0.90%)	(0.20%)	(0.60%)
Other permanent differences	(0.10%)	(0.10%)	(0.30%)
Effective tax rate	21.80%	23.30%	22.70%

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($)	Dec. 31, 2024	Dec. 31, 2023
Deferred tax assets
Accrued expenses and allowances	$ 41,031,000	$ 41,894,000
Inventories	6,892,000	10,685,000
Net operating loss carryforwards	24,381,000	7,663,000
Amortizable assets	39,657,000	5,798,000
Other	5,916,000	9,149,000
Subtotal	117,877,000	75,189,000
Less: valuation allowance	(1,150,000)	(816,000)
Total net deferred tax assets	116,727,000	74,373,000
Deferred tax liabilities
Property, plant and equipment	(1,014,515,000)	(1,013,045,000)
Other	(4,398,000)	(6,096,000)
Total deferred tax liabilities	(1,018,913,000)	(1,019,141,000)
Net deferred tax liability	$ (902,186,000)	$ (944,768,000)

Income Taxes - Schedule of Unre

Income Taxes - Schedule of Unrecognized Tax Benefits Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Taxes
Unrecognized Tax Benefits, Beginning Balance	$ 31,258	$ 28,646	$ 20,466
Increases related to current year tax positions	5,115	1,500	9,600
Increases related to prior year tax positions	263	1,798	364
Decreases related to prior year tax positions	(6,949)	(686)	(1,784)
Unrecognized Tax Benefits, Ending Balance	$ 29,687	$ 31,258	$ 28,646

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Feb. 28, 2025	Nov. 30, 2023	Nov. 30, 2022	Feb. 28, 2022	Jul. 31, 2021
Dividends declared	$ 284,122	$ 280,501	$ 245,287
Dividends declared per share (in dollars per share)	$ 1.84	$ 1.7	$ 1.36
Dividends paid	$ 282,616	$ 271,317	$ 237,163
Authorized share purchase program					$ 1,500,000	$ 1,500,000	$ 1,250,000	$ 1,000,000
Share repurchases (in shares)	9.4	13.4	23
Share repurchases	$ 1,212,164	$ 1,452,203	$ 1,800,905
Remaining authorized repurchase amount	$ 193,500
Subsequent Event
Authorized share purchase program				$ 1,500,000

Equity-Based Incentive Plans -

Equity-Based Incentive Plans - 2023 Equity Incentive Plan (Details)	12 Months Ended
	Dec. 31, 2024 $ / shares shares	Dec. 31, 2023 shares	Dec. 31, 2022 shares	May 31, 2023 shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Retirement Eligible Age For Vesting Of Awards	59 years 6 months
Restricted Stock Units (RSUs)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period	374,370	433,810	481,926
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage	100%
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period	2 years
Restricted Stock Units (RSUs) | Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period	2 years	2 years	2 years
Restricted Stock Units (RSUs) | Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period	4 years	4 years	4 years
Deferred Stock Units (DSUs)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period	13,000	18,000	20,000
Stock Appreciation Rights (SARs)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested And Vested, Number	1,300
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Intrinsic Value, Amount Per Share | $ / shares	$ 42.83
Equity Incentive 2023 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized				9,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant	6,200,000
Equity Incentive 2023 Plan | Stock Options And Stock Appreciation Rights [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Share Limit Against Which Full Value Awards Will Be Counted	1
Equity Incentive 2023 Plan | Restricted Stock Units, Deferred Stock Units, Restricted Stock And Unrestricted Stock Awards, And Performance Awards [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Share Limit Against Which Full Value Awards Will Be Counted	2.09
Equity Incentive 2023 Plan | Restricted Stock Units (RSUs)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period	0
Equity Incentive 2023 Plan | Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested And Vested, Number	0
Equity Incentive 2023 Plan | Unrestricted Stock Awards
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested And Vested, Number	0

Equity-Based Incentive Plans _2

Equity-Based Incentive Plans - Restricted Stock Units (Details) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Number of RSUs
Outstanding	849,491	973,551	1,348,258
Granted	374,370	433,810	481,926
Vested	(394,675)	(517,041)	(786,622)
Forfeited	(39,874)	(40,829)	(70,011)
Outstanding	789,312	849,491	973,551
Weighted Average Grant Date Fair Value
Outstanding	$ 99.13	$ 71.8	$ 43.82
Granted	137.14	108.95	98.29
Vested	94.28	64.03	37.38
Forfeited	104.21	78.7	46.82
Outstanding	$ 115.47	$ 99.13	$ 71.8
Aggregate Intrinsic Value
Outstanding	$ 90,037	$ 101,480	$ 94,765	$ 83,686
Unrecognized Compensation
Outstanding	$ 54,964	43,073	44,394	$ 39,657
Share-Based Payment Arrangement, Additional Disclosure [Abstract]
Weighted average remaining life	1 year 7 months 6 days
Fair value of instruments vested during the period	$ 56,200	$ 58,300	$ 79,100
Total shares withheld	287,000	342,000	249,000

Equity-Based Incentive Plans _3

Equity-Based Incentive Plans - Long-Term Incentive Compensation Program (Details)	12 Months Ended
	Dec. 31, 2024 shares
Performance Shares [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
General performance period	3 years
Growth and profitability measures	4
Performance Shares [Member] | Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Awards earned as percentage of specified compensation	0%
Performance Shares [Member] | Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Awards earned as percentage of specified compensation	100%
2021 Award | Senior Executive Officers | Three-year performance period award
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Maximum Shares That Could Be Issued	360,189
Award Earned	324,173
Awards Issued/Issuable	324,173
2022 Award | Senior Executive Officers | Three-year performance period award
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Maximum Shares That Could Be Issued	249,759
Award Earned	249,759
Awards Issued/Issuable	249,759
2023 Award | Senior Executive Officers | One-year performance period transition award
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Maximum Shares That Could Be Issued	3,678
Award Earned	2,759
Awards Issued/Issuable	2,759
2023 Award | Senior Executive Officers | Two-year performance period transition award
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Maximum Shares That Could Be Issued	5,517
Award Earned	4,690
Awards Issued/Issuable	4,690
2023 Award | Senior Executive Officers | Three-year performance period award
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Maximum Shares That Could Be Issued	193,946
2024 Award | Senior Executive Officers | Three-year performance period award
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Maximum Shares That Could Be Issued	172,425

Equity-Based Incentive Plans _4

Equity-Based Incentive Plans - 2018 Executive Incentive Compensation Plan (Details) - Executive Incentive Compensation Plan 2018 - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized	2,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage	33.33%
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant	1,300,000	1,300,000	1,400,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Non-Option Equity Instruments, Granted	17,000	29,000	26,000
Award Market Value	$ 2.2	$ 3.5	$ 3.2
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period	2 years

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Assets and liabilities subject to fair value measurements
Carrying amount	$ 3,231,007	$ 3,071,056
Level 2
Assets and liabilities subject to fair value measurements
Fair value of long-term debt, including current maturities	3,000,000	2,800,000
Recurring
Assets and liabilities subject to fair value measurements
Short-term investments	147,811	721,210
Recurring | Level 2
Assets and liabilities subject to fair value measurements
Short-term investments	147,811	721,210
Futures | Recurring | Commodity contract
Assets and liabilities subject to fair value measurements
Commodity futures - financial assets	19,323	2,483
Commodity futures - financial liabilities	6,272	9,305
Futures | Recurring | Level 2 | Commodity contract
Assets and liabilities subject to fair value measurements
Commodity futures - financial assets	19,323	2,483
Commodity futures - financial liabilities	$ 6,272	$ 9,305

Commitments and Contingencies_2

Commitments and Contingencies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($)
Loss Contingencies [Line Items]
Purchase Commitments Physical Commodity Requirements Utilization Period	3 years
Unrecorded Unconditional Purchase Obligation, Total	$ 661,479
Capital Addition Purchase Commitments
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation, Total	$ 578,800
Water Products
Loss Contingencies [Line Items]
Long-Term Purchase Commitment, Period	27 years
Maximum | Physical Commodity and Commodity Transportation
Loss Contingencies [Line Items]
Long-Term Purchase Commitment, Period	5 years
Maximum | Air Products
Loss Contingencies [Line Items]
Long-Term Purchase Commitment, Period	15 years

Commitments and Contingencies -

Commitments and Contingencies - Schedule of Unconditional Purchase Obligations (Details) $ in Thousands	Dec. 31, 2024 USD ($)
Commitments and Contingencies
2025	$ 358,976
2026	57,430
2027	37,483
2028	24,360
2029	18,698
Thereafter	164,532
Unrecorded Unconditional Purchase Obligation, Total	$ 661,479

Transactions with Affiliated _3

Transactions with Affiliated Companies - Schedule of Related Party Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Total net sales	$ 17,540,390	$ 18,795,316	$ 22,260,774
Purchases	14,737,804	14,749,433	16,142,943
Related Party [Member]
Related Party Transaction [Line Items]
Total net sales	720,742	680,004	791,523
Accounts receivable, net	54,230	73,245
Accounts payable	7,267	9,685
Related Party [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Total net sales	720,742	680,004	791,523
Accounts receivable, net	54,230	73,245	79,769
Purchases	188,906	167,798	127,860
Accounts payable	$ 7,267	$ 9,685	$ 9,934

Retirement Plans (Details)

Retirement Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Retirement Plans
Defined Contribution Plan, Cost	$ 209	$ 312.4	$ 466.9
Profit sharing component	$ 165.2	$ 264.6	$ 421.6
Percentage of employer's profit sharing contribution	8%	8%	8%
Employer's contribution to profit sharing plans for eligible employees	$ 132.2	$ 211.6	$ 337.2

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Option to extend operating lease	true
Option to terminate operating lease	true
Weighted average remaining lease term	9 years	9 years
Weighted average discount rate	4.46%	4.31%
Operating lease expenses	$ 27.4	$ 27.9	$ 23.7
Short term lease expenses	51.3	40.4	35.8
Cash paid related to operating lease obligations	23.2	22.8	20.1
Right-of-use assets obtained in exchange for operating lease liabilities	$ 12.8	$ 38.8	30.9
ROCA ACERO, S.A. de C.V.
Right-of-use assets obtained in exchange for operating lease liabilities			$ 16.8

Leases - Schedule of Operating

Leases - Schedule of Operating lease right-of-use assets and lease obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Leases
Right of use asset	$ 113,500	$ 127,499
Right of use asset included in balance sheet	Other assets	Other assets
Current lease liability	$ 19,915	$ 21,003
Current lease liability included in balance sheet	Accrued expenses	Accrued expenses
Non current lease liability	$ 94,417	$ 107,147
Non current lease liability included in balance sheet	Other liabilities	Other liabilities
Lease liability	$ 114,332	$ 128,150

Leases - Future operating lease

Leases - Future operating lease liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Future operating lease liabilities
2025	$ 24,207
2026	19,315
2027	16,411
2028	13,673
2029	10,885
Thereafter	54,126
Total undiscounted cash flows	138,617
Less imputed interest	(24,285)
Lease obligations under operating leases	$ 114,332	$ 128,150

Segment Information - Results (

Segment Information - Results (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information
Total net sales	$ 17,540,390	$ 18,795,316	$ 22,260,774
Costs of goods sold	14,737,804	14,749,433	16,142,943
Other segment items	859,549	894,702	1,026,009
Operating income (loss)	1,943,037	3,151,181	5,091,822
Interest expense, net of capitalized interest	56,347	76,484	91,538
Other (income) expense, net	(96,191)	(144,246)	(20,785)
Income (loss) before income taxes	1,982,881	3,218,943	5,021,069
Depreciation and amortization	478,907	437,804	384,202
Capital expenditures	1,868,006	1,657,905	908,902
Total Assets	14,935,233	14,908,420
U.S.
Segment Reporting Information
Total net sales	16,075,560	16,967,684	20,851,771
Non-U.S.
Segment Reporting Information
Total net sales	1,464,830	1,827,632	1,409,003
Operating Segment | Steel Operations
Segment Reporting Information
Total net sales	12,527,066	13,067,622	15,100,996
Costs of goods sold	10,736,557	10,977,249	11,787,382
Other segment items	208,135	208,773	220,925
Operating income (loss)	1,582,374	1,881,600	3,092,689
Depreciation and amortization	351,558	331,225	295,468
Capital expenditures	461,524	453,955	613,678
Total Assets	8,776,445	8,650,450
Operating Segment | Steel Operations | U.S.
Segment Reporting Information
Total net sales	11,311,552	11,603,139	13,783,666
Operating Segment | Steel Operations | Non-U.S.
Segment Reporting Information
Total net sales	749,932	1,037,412	779,683
Operating Segment | Steel Operations | Other segments
Segment Reporting Information
Total net sales	465,582	427,071	537,647
Operating Segment | Metals Recycling Operations
Segment Reporting Information
Total net sales	4,136,913	4,158,588	4,200,227
Costs of goods sold	3,946,457	3,971,743	3,986,236
Other segment items	113,649	139,110	114,619
Operating income (loss)	76,807	47,735	99,372
Depreciation and amortization	56,148	65,803	48,851
Capital expenditures	83,020	185,903	63,967
Total Assets	1,301,234	1,340,445
Operating Segment | Metals Recycling Operations | U.S.
Segment Reporting Information
Total net sales	1,311,124	1,162,246	1,293,258
Operating Segment | Metals Recycling Operations | Non-U.S.
Segment Reporting Information
Total net sales	694,010	774,211	602,555
Operating Segment | Metals Recycling Operations | Other segments
Segment Reporting Information
Total net sales	2,131,779	2,222,131	2,304,414
Operating Segment | Steel Fabrication Operations
Segment Reporting Information
Total net sales	1,771,795	2,806,777	4,257,207
Costs of goods sold	1,006,211	1,115,515	1,737,366
Other segment items	98,600	98,001	95,186
Operating income (loss)	666,984	1,593,261	2,424,655
Depreciation and amortization	11,071	9,787	9,727
Capital expenditures	29,374	22,044	17,519
Total Assets	665,867	790,399
Operating Segment | Steel Fabrication Operations | U.S.
Segment Reporting Information
Total net sales	1,761,771	2,798,262	4,245,803
Operating Segment | Steel Fabrication Operations | Non-U.S.
Segment Reporting Information
Total net sales	1,731	672	183
Operating Segment | Steel Fabrication Operations | Other segments
Segment Reporting Information
Total net sales	8,293	7,843	11,221
Operating Segment | Aluminum Operations
Segment Reporting Information
Total net sales	318,689	285,907	292,085
Costs of goods sold	298,572	237,759	266,950
Other segment items	92,448	31,002	10,365
Operating income (loss)	(72,331)	17,146	14,770
Depreciation and amortization	6,786	4,917	5,127
Capital expenditures	1,309,027	967,739	189,805
Total Assets	2,802,647	1,444,335
Operating Segment | Aluminum Operations | U.S.
Segment Reporting Information
Total net sales	256,051	239,095	252,121
Operating Segment | Aluminum Operations | Non-U.S.
Segment Reporting Information
Total net sales	2,496	9,105	16,806
Operating Segment | Aluminum Operations | Other segments
Segment Reporting Information
Total net sales	60,142	37,707	23,158
Operating Segment | Other
Segment Reporting Information
Total net sales	1,451,723	1,171,901	1,287,980
Costs of goods sold	1,420,978	1,147,441	1,295,721
Other segment items	348,153	419,037	586,304
Operating income (loss)	(317,408)	(394,577)	(594,045)
Depreciation and amortization	53,344	26,072	25,029
Capital expenditures	55,183	28,264	23,933
Total Assets	3,319,917	3,248,822
Operating Segment | Other | U.S.
Segment Reporting Information
Total net sales	1,435,062	1,164,942	1,276,923
Operating Segment | Other | Non-U.S.
Segment Reporting Information
Total net sales	16,661	6,232	9,776
Operating Segment | Other | Other segments
Segment Reporting Information
Total net sales		727	1,281
Eliminations
Segment Reporting Information
Total net sales	(2,665,796)	(2,695,479)	(2,877,721)
Costs of goods sold	(2,670,971)	(2,700,274)	(2,930,712)
Other segment items	(1,436)	(1,221)	(1,390)
Operating income (loss)	6,611	6,016	54,381
Capital expenditures	(70,122)
Total Assets	(1,930,877)	(566,031)
Eliminations | Other segments
Segment Reporting Information
Total net sales	$ (2,665,796)	$ (2,695,479)	$ (2,877,721)