KAISER ALUMINUM CORP, 10-K filed on 2/20/2025
Annual Report
v3.25.0.1
Document and Entity Information - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2024
Feb. 17, 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    
Entity File Number 1-09447    
Entity Registrant Name KAISER ALUMINUM CORPORATION    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 94-3030279    
Entity Address, Address Line One 1550 West McEwen Drive    
Entity Address, Address Line Two Suite 500    
Entity Address, City or Town Franklin    
Entity Address, State or Province TN    
Entity Address, Postal Zip Code 37067    
City Area Code 629    
Local Phone Number 252-7040    
Title of 12(b) Security Common stock, par value $0.01 per share    
Trading Symbol KALU    
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    
Document Financial Statement Error Correction [Flag] false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Public Float     $ 1.0
Entity Common Stock, Shares Outstanding   16,100,473  
Documents Incorporated by Reference

Documents Incorporated by Reference. Certain portions of the registrant’s definitive proxy statement related to the registrant’s 2025 annual meeting of stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K.

    
ICFR Auditor Attestation Flag true    
Entity Central Index Key 0000811596    
Current Fiscal Year End Date --12-31    
Document Fiscal Year Focus 2024    
Document Fiscal Period Focus FY    
Amendment Flag false    
Auditor Firm ID 34    
Auditor Name Deloitte & Touche LLP    
Auditor Location Nashville, Tennessee    
Auditor Opinion

Opinions on the Financial Statements and Internal Control over Financial Reporting

We have audited the accompanying consolidated balance sheets of Kaiser Aluminum Corporation and subsidiaries (the "Company") as of December 31, 2024 and 2023, the related consolidated statements of income (loss), comprehensive income (loss), stockholders' equity, and cash flows, for each of the three years in the period ended December 31, 2024, and the related notes (collectively referred to as the "financial statements"). We also have audited the Company's internal control over financial reporting as of December 31, 2024, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).

In our opinion, the financial statements referred to above present fairly, in all material respects, the financial position of the Company as of December 31, 2024 and 2023, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2024, in conformity with accounting principles generally accepted in the United States of America (“generally accepted accounting principles”). Also, in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2024, based on criteria established in Internal Control — Integrated Framework (2013) issued by COSO.

    
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CONSOLIDATED BALANCE SHEETS - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Current assets:    
Cash and cash equivalents $ 18.4 $ 82.4
Receivables:    
Trade receivables, net 319.7 325.2
Other 22.0 12.4
Contract assets 73.4 58.5
Inventories 503.9 477.2
Prepaid expenses and other current assets 39.0 34.5
Total current assets 976.4 990.2
Property, plant and equipment, net 1,161.2 1,052.1
Operating lease assets 27.2 32.6
Deferred tax assets, net 7.2 6.0
Intangible assets, net 45.5 50.0
Goodwill 18.8 18.8
Other assets 78.6 117.7
Total assets 2,314.9 2,267.4
Current liabilities:    
Accounts payable 266.9 252.7
Accrued salaries, wages and related expenses 54.3 53.0
Other accrued liabilities 79.4 64.3
Total current liabilities 400.6 370.0
Long-term portion of operating lease liabilities 25.2 29.2
Pension and other postretirement benefits 71.4 76.8
Net liabilities of Salaried VEBA   3.8
Deferred tax liabilities 24.1 13.9
Long-term liabilities 84.0 81.7
Long-term debt, net 1,041.6 1,039.8
Total liabilities 1,646.9 1,615.2
Commitments and contingencies - Note 10
Stockholders’ equity:    
Preferred stock, 5,000,000 shares authorized at both December 31, 2024 and December 31, 2023; no shares were issued and outstanding at December 31, 2024 and December 31, 2023
Common stock, par value $0.01, 90,000,000 shares authorized at both December 31, 2024 and December 31, 2023; 22,931,184 shares issued and 16,095,898 shares outstanding at December 31, 2024; 22,851,077 shares issued and 16,015,791 shares outstanding at December 31, 2023 0.2 0.2
Additional paid in capital 1,117.0 1,104.7
Retained earnings 6.2 10.1
Treasury stock, at cost, 6,835,286 shares at both December 31, 2024 and December 31, 2023 (475.9) (475.9)
Accumulated other comprehensive income 20.5 13.1
Total stockholders’ equity 668.0 652.2
Total liabilities and stockholders' equity $ 2,314.9 $ 2,267.4
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CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares
Dec. 31, 2024
Dec. 31, 2023
Statement of Financial Position [Abstract]    
Preferred stock, shares authorized 5,000,000 5,000,000
Preferred stock, shares issued 0 0
Preferred stock, shares outstanding 0 0
Common stock, par value $ 0.01 $ 0.01
Common stock, shares authorized 90,000,000 90,000,000
Common Stock, shares issued 22,931,184 22,851,077
Common stock, shares outstanding 16,095,898 16,015,791
Treasury stock, shares 6,835,286 6,835,286
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STATEMENTS OF CONSOLIDATED INCOME (LOSS) - USD ($)
shares in Thousands, $ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Income Statement [Abstract]      
Net sales $ 3,024.0 $ 3,087.0 $ 3,427.9
Costs and expenses:      
Cost of products sold, excluding depreciation and amortization 2,691.1 2,754.9 3,180.2
Depreciation and amortization 116.4 108.6 106.9
Selling, general, administrative, research and development 120.8 122.7 110.9
Goodwill impairment 0.0 0.0 20.5
Restructuring costs 7.6 5.0 2.2
Other operating charges, net 0.4 0.0 3.2
Total costs and expenses 2,936.3 2,991.2 3,423.9
Operating income 87.7 95.8 4.0
Other (expense) income:      
Interest expense (43.7) (46.9) (48.3)
Other income, net - Note 13 19.5 7.4 6.4
Income (loss) before income taxes 63.5 56.3 (37.9)
Income tax (provision) benefit (16.7) (9.1) 8.3
Net income (loss) $ 46.8 $ 47.2 $ (29.6)
Net income (loss) per common share:      
Basic $ 2.91 $ 2.95 $ (1.86)
Diluted $ 2.87 $ 2.92 $ (1.86)
Weighted-average number of common shares outstanding (in thousands):      
Basic 16,069 15,991 15,906
Diluted 16,319 16,131 15,906
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STATEMENTS OF CONSOLIDATED COMPREHENSIVE INCOME (LOSS) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Statement of Comprehensive Income [Abstract]      
Net income (loss) $ 46.8 $ 47.2 $ (29.6)
Other comprehensive income (loss), net of tax-Note 11:      
Defined benefit plans 8.1 8.2 24.2
Cash flow hedges (0.7) 1.7 (17.3)
Other comprehensive (loss) income, net of tax 7.4 9.9 6.9
Comprehensive income (loss) $ 54.2 $ 57.1 $ (22.7)
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STATEMENTS OF CONSOLIDATED STOCKHOLDERS' EQUITY - USD ($)
$ in Millions
Total
Common Stock
Additional Paid In Capital
Retained Earnings
Treasury Stock
Accumulated Other Comprehensive (Loss) Income
Beginning balance at Dec. 31, 2021 $ 692.5 $ 0.2 $ 1,078.9 $ 93.0 $ (475.9) $ (3.7)
Beginning balance (shares) at Dec. 31, 2021   15,865,118        
Net Income (Loss) (29.6)     (29.6)    
Other comprehensive income, net of tax 6.9         6.9
Common shares issued (including impacts from Long-Term Incentive programs) 0.6   0.6      
Common shares issued (including impacts from Long-Term Incentive programs) (shares)   107,494        
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares/common shares issued (2.8)   (2.8)      
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares/common shares issued (shares)   (31,856)        
Cash dividends declared [1] (50.1)     (50.1)    
Amortization of unearned equity compensation 13.7   13.7      
Ending balance at Dec. 31, 2022 631.2 $ 0.2 1,090.4 13.3 (475.9) 3.2
Ending balance (shares) at Dec. 31, 2022   15,940,756        
Net Income (Loss) 47.2     47.2    
Other comprehensive income, net of tax 9.9         9.9
Common shares issued (including impacts from Long-Term Incentive programs) 0.7   0.7      
Common shares issued (including impacts from Long-Term Incentive programs) (shares)   98,292        
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares/common shares issued (1.8)   (1.8)      
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares/common shares issued (shares)   (23,257)        
Cash dividends declared [1] (50.4)     (50.4)    
Amortization of unearned equity compensation 15.4   15.4      
Ending balance at Dec. 31, 2023 $ 652.2 $ 0.2 1,104.7 10.1 (475.9) 13.1
Ending balance (shares) at Dec. 31, 2023 16,015,791 16,015,791        
Net Income (Loss) $ 46.8     46.8    
Other comprehensive income, net of tax 7.4         7.4
Common shares issued (including impacts from Long-Term Incentive programs) 0.6   0.6      
Common shares issued (including impacts from Long-Term Incentive programs) (shares)   107,017        
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares/common shares issued (2.1)   (2.1)      
Cancellation of shares to cover employees' tax withholdings upon vesting of non-vested shares/common shares issued (shares)   (26,910)        
Cash dividends declared [1] (50.7)     (50.7)    
Amortization of unearned equity compensation 13.8   13.8      
Ending balance at Dec. 31, 2024 $ 668.0 $ 0.2 $ 1,117.0 $ 6.2 $ (475.9) $ 20.5
Ending balance (shares) at Dec. 31, 2024 16,095,898 16,095,898        
[1] Dividends declared per common share were $3.08 for each of the years ended December 31, 2024, 2023, and 2022.
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STATEMENTS OF CONSOLIDATED STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Statement of Stockholders' Equity [Abstract]      
Cash dividends declared (in dollars per share) $ 3.08 $ 3.08 $ 3.08
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STATEMENTS OF CONSOLIDATED CASH FLOWS - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Cash flows from operating activities:      
Net income (loss) $ 46.8 $ 47.2 $ (29.6)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:      
Depreciation of property, plant and equipment 111.9 103.3 97.6
Amortization of definite-lived intangible assets 4.5 5.3 9.3
Amortization of debt premium and debt issuance costs 2.3 2.2 2.3
Deferred income taxes 6.8 7.5 (12.0)
LIFO valuation inventory expense 3.5 1.0 22.0
Non-cash equity compensation 14.4 16.1 14.3
Non-cash asset impairment charges 3.6   23.7
Gain on disposition of property, plant and equipment (3.3) (13.8) (6.0)
Gain on reimbursement on certain machinery and equipment - Note 13     (6.0)
Bad debt expense 0.3    
Non-cash postretirement and postemployment defined benefit plan cost 9.0 13.4 13.1
Changes in operating assets and liabilities:      
Trade and other receivables (4.4) 33.1 15.0
Contract assets (14.9) 0.1 4.6
Inventories (excluding LIFO adjustments) (29.4) 47.2 (142.8)
Prepaid expenses and other current assets (9.6) (2.8) (1.5)
Accounts payable 14.1 (43.0) (61.2)
Accrued liabilities 10.0 6.6 4.4
Annual variable cash contributions to Salaried VEBA (1.1)    
Long-term assets and liabilities, net 2.6 (11.5) (10.3)
Net cash provided by (used in) operating activities 167.1 211.9 (63.1)
Cash flows from investing activities:      
Capital expenditures (180.8) (143.2) (142.5)
Purchase of equity securities (0.1) (0.3) (0.3)
Proceeds from sale of equity securities 0.3 0.1  
Proceeds from reimbursement on certain machinery and equipment - Note 13     6.0
Proceeds from disposition of property, plant and equipment 6.0 15.2 11.0
Net cash used in investing activities (174.6) (128.2) (125.8)
Cash flows from financing activities:      
Borrowings under the Revolving Credit Facility   215.1  
Repayment of borrowings under the Revolving Credit Facility   (215.1)  
Cash paid for debt issuance costs     (1.8)
Repayment of finance lease (2.5) (2.1) (2.1)
Cancellation of shares to cover tax withholdings upon common shares issued (2.1) (1.8) (2.8)
Cash dividends and dividend equivalents paid (50.7) (50.4) (50.1)
Net cash used in financing activities (55.3) (54.3) (56.8)
Net (decrease) increase in cash, cash equivalents and restricted cash during the period (62.8) 29.4 (245.7)
Cash, cash equivalents and restricted cash at beginning of period 100.7 71.3 317.0
Cash, cash equivalents and restricted cash at end of period $ 37.9 $ 100.7 $ 71.3
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STATEMENTS OF CONSOLIDATED CASH FLOWS (Parenthetical) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2022
Inventory write-down related to certain alloying metals $ 3,200,000  
Impairment charge on land held for sale 400,000 $ 0
Goodwill impairment 0 20,500,000
Other operating charge $ 400,000 3,200,000
Favorable Commodity Contract Intangible Asset    
Other operating charge   $ 3,200,000
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Cybersecurity Risk Management, Strategy, and Governance
 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]

Item 1C. Cybersecurity

Risk Management and Strategy

We employ information systems to support our business. As is the case for other manufacturing companies of comparable size and scope, we, from time to time, experience attempted cyber-attacks on our information system. We also face risks associated with other potential significant failures or disruptions of our information technology networks. We utilize a risk-based, multi-layered information security approach that incorporates some of the National Institute of Standards and Technology (“NIST”) Cybersecurity Framework (“CSF”). We have adopted and implemented this approach to identify and mitigate information security risks in a manner that we believe is commercially reasonable for manufacturing companies of our size and scope.

The review of cybersecurity risks and threats is integrated into our enterprise risk management (“ERM”). Our ERM program includes an annual risk prioritization process to identify key enterprise risks. Each key risk is assigned risk owners to establish action plans and implement risk mitigation strategies. The cybersecurity threat risk action plan is managed at the enterprise level by our Chief Information Officer (“CIO”), who reports to our Executive Vice President and Chief Financial Officer. Management employs in-depth defense mechanisms throughout the enterprise. We regularly engage and consult with independent third-party consultants as part of our overall ERM, including penetration testing and periodic tabletop exercises to better prepare us for potential cyber threats. We also conduct annual information security training to educate employees and make them aware of information security risks and to enable them to take steps to mitigate those risks. As part of this program, we take reasonable steps to provide our executive management and employees who may come into possession of confidential financial information with appropriate information security awareness

training. In addition, we employ multi-factor authentication and vulnerability management to mitigate and/or prevent cybersecurity incidents.

A cybersecurity incident may be detected in a number of ways, including, but not limited to, through automated reporting mechanisms, network and system indicators, intrusion detection systems, employee reports, law enforcement reports, or other third-party notification. To oversee and identify cybersecurity threat risks on a day-to-day basis, including from third-party service providers, the Company maintains a cybersecurity operations team with round-the-clock monitoring, and the CIO and Director of Cybersecurity receive regular reports on industry activity. Upon receiving notification of a cybersecurity incident, the cybersecurity operations team acts to isolate and contain the threat. The CIO along with the Director of Cybersecurity will consult and determine the incident severity level, which determines whether the incident should be escalated. Critical and high severity incidents must be reported to our President and Chief Executive Officer, Executive Vice President and Chief Financial Officer, Executive Vice President, Chief Administrative Officer and General Counsel and Executive Vice President - Manufacturing. The Company may engage third-party experts for assistance with crisis management, including forensic investigations, ransom negotiation, or crisis communication. During this process, the cybersecurity operations team will take steps to preserve evidence as soon as possible, including, but not limited to, memory dumps, log preservation and forensic hard drive collection. In addition, our Executive Vice President, Chief Administrative Officer and General Counsel, in consultation with the CIO and Director of Cybersecurity, will promptly evaluate whether the incident requires legal notifications or disclosure, including whether the incident requires disclosure under the U.S. securities laws. Following a cybersecurity incident, the Executive Vice President and Chief Financial Officer will direct the development of documentation regarding lessons learned in the response, including evaluation of preparedness capability, to continuously strengthen the cybersecurity posture of the Corporation.

Management has not identified risks from cybersecurity threats, including as a result of any previous cybersecurity incidents involving us or third-parties, that have materially affected or are reasonably likely to materially affect the Company in 2024, including its business, strategy, results of operations, or financial condition. See “Item 1A. Risk Factors - Risks Related to Cybersecurity and Privacy” for additional information. While we continually work to safeguard the information systems we use, and the proprietary, confidential and personal information residing therein, and mitigate potential risks, there can be no assurance that such actions will be sufficient to prevent cybersecurity incidents or mitigate all potential risks to such systems, networks and data or those of our third-party providers. In the event an attack or other intrusion were to be successful, we have a response team of internal and external resources engaged and prepared to respond. We also have a cyber risk insurance policy to help us mitigate risk exposure by offsetting costs involved with recovery and remediation in the event of a successful attack or other intrusion.

Governance

The Audit Committee is responsible for the review of risks relating to our information technology system, including cybersecurity, emerging cybersecurity developments and threats and our strategy for mitigating cybersecurity risks. Our entire Board of Directors is responsible for overseeing management’s risk assessment and risk management processes designed to monitor and mitigate information security risks. The CIO and Director of Cybersecurity reports on cybersecurity matters semi-annually to the Board, primarily through the Audit Committee. Management provides benchmarking information and updates on key operational and compliance metrics to the Audit Committee. In addition, cybersecurity training is provided to the Audit Committee, to educate directors on the current cybersecurity threat environment and measures companies can take to mitigate the risk and impact of cyberattacks.

As described above, management is actively involved in assessing and managing the Company’s material cybersecurity risks. The CIO and the Director of Cybersecurity primarily lead these efforts. The CIO, reporting to the Company’s Executive Vice President and Chief Financial Officer, manages the global information technology and cybersecurity programs. The CIO holds bachelor’s and master’s degrees in business administration, specializing in information systems and quantitative methods from Loyola Marymount University. The CIO has over 25 years of information technology expertise with extensive experience in enterprise risk management, including analysis, development, evaluation, and testing of control objectives and procedures to mitigate risks. The Director of Cybersecurity oversees and helps to ensure appropriate capabilities and controls are implemented in the areas of network security, endpoint protection, data protection, incident response, identity, and access management. Additionally, in this role, the Director of Cybersecurity works closely with third-party security partners surrounding monitoring and incident response services.
Cybersecurity Risk Management Processes Integrated [Flag] true
Cybersecurity Risk Management Processes Integrated [Text Block] The review of cybersecurity risks and threats is integrated into our enterprise risk management (“ERM”). Our ERM program includes an annual risk prioritization process to identify key enterprise risks. Each key risk is assigned risk owners to establish action plans and implement risk mitigation strategies.
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]

The Audit Committee is responsible for the review of risks relating to our information technology system, including cybersecurity, emerging cybersecurity developments and threats and our strategy for mitigating cybersecurity risks. Our entire Board of Directors is responsible for overseeing management’s risk assessment and risk management processes designed to monitor and mitigate information security risks. The CIO and Director of Cybersecurity reports on cybersecurity matters semi-annually to the Board, primarily through the Audit Committee. Management provides benchmarking information and updates on key operational and compliance metrics to the Audit Committee. In addition, cybersecurity training is provided to the Audit Committee, to educate directors on the current cybersecurity threat environment and measures companies can take to mitigate the risk and impact of cyberattacks.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block] The Audit Committee is responsible for the review of risks relating to our information technology system, including cybersecurity, emerging cybersecurity developments and threats and our strategy for mitigating cybersecurity risks.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block] The CIO and Director of Cybersecurity reports on cybersecurity matters semi-annually to the Board, primarily through the Audit Committee.
Cybersecurity Risk Role of Management [Text Block]

As described above, management is actively involved in assessing and managing the Company’s material cybersecurity risks. The CIO and the Director of Cybersecurity primarily lead these efforts. The CIO, reporting to the Company’s Executive Vice President and Chief Financial Officer, manages the global information technology and cybersecurity programs. The CIO holds bachelor’s and master’s degrees in business administration, specializing in information systems and quantitative methods from Loyola Marymount University. The CIO has over 25 years of information technology expertise with extensive experience in enterprise risk management, including analysis, development, evaluation, and testing of control objectives and procedures to mitigate risks. The Director of Cybersecurity oversees and helps to ensure appropriate capabilities and controls are implemented in the areas of network security, endpoint protection, data protection, incident response, identity, and access management. Additionally, in this role, the Director of Cybersecurity works closely with third-party security partners surrounding monitoring and incident response services.
Cybersecurity Risk Management Positions or Committees Responsible [Flag] true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block] The CIO and the Director of Cybersecurity primarily lead these efforts. The CIO, reporting to the Company’s Executive Vice President and Chief Financial Officer, manages the global information technology and cybersecurity programs.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block] The CIO has over 25 years of information technology expertise with extensive experience in enterprise risk management, including analysis, development, evaluation, and testing of control objectives and procedures to mitigate risks.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block] The CIO has over 25 years of information technology expertise with extensive experience in enterprise risk management, including analysis, development, evaluation, and testing of control objectives and procedures to mitigate risks. The Director of Cybersecurity oversees and helps to ensure appropriate capabilities and controls are implemented in the areas of network security, endpoint protection, data protection, incident response, identity, and access management. Additionally, in this role, the Director of Cybersecurity works closely with third-party security partners surrounding monitoring and incident response services.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag] true
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Pay vs Performance Disclosure - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Pay vs Performance Disclosure      
Net Income (Loss) $ 46.8 $ 47.2 $ (29.6)
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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
Rule 10b5-1 Arrangement Modified false
Non-Rule 10b5-1 Arrangement Modified false
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Summary of Significant Accounting Policies
 12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]  
Summary of Significant Accounting Policies

1. Summary of Significant Accounting Policies

In this Form 10-K, unless the context otherwise requires, references in these notes to consolidated financial statements to “Kaiser Aluminum Corporation,” “Kaiser,” “we,” “us,” “our,” “the Company” and “our Company” refer collectively to Kaiser Aluminum Corporation and its subsidiaries.

Organization and Nature of Operations. Kaiser Aluminum Corporation specializes in the production of semi-fabricated specialty aluminum mill products, such as aluminum plate and sheet, bare and coated coil and extruded and drawn products, for the following end market applications: (i) Aero/HS Products; (ii) Packaging; (iii) GE Products; (iv) Automotive Extrusions; and (v) Other products. Our business is organized into one operating segment. See Note 17 for additional information regarding our business, product and geographical area information and concentration of risk.

Principles of Consolidation and Basis of Presentation. Our consolidated financial statements include the accounts of our wholly owned subsidiaries and are prepared in accordance with GAAP and the rules and regulations of the SEC. Intercompany balances and transactions are eliminated. We have reclassified certain items in prior periods to conform to current classifications.

Use of Estimates in the Preparation of Financial Statements. The preparation of financial statements in accordance with GAAP requires the use of estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities known to exist as of the date the financial statements are published and the reported amounts of revenues and expenses during the reporting period. Uncertainties with respect to such estimates and assumptions are inherent in the preparation of our consolidated financial statements; accordingly, it is possible that the actual results could differ from these estimates and assumptions, which could have a material effect on the reported amounts of our consolidated financial position and results of operations.

Supply Chain Financing. We have several supply chain financing arrangements, in which we may sell certain of our customers’ trade accounts receivable to such customers’ financial institutions without recourse. We sell our undivided interests in certain of these receivables at our discretion when we determine that the cost of these arrangements is less than the cost of servicing our receivables with existing debt. Under the terms of the agreements, we retain no rights or interest, have no obligations with respect to the sold receivables and do not service the receivables after the sale. As such, we account for these transactions as a sale (see Note 13).

Fair Value Measurements. We apply the fair value hierarchy established by GAAP for the recognition and measurement of certain financial assets and liabilities. An asset or liability’s fair value classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. In determining fair value, we utilize valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible and consider counterparty risk in our assessment of fair value. We also review the underlying inputs that are significant to the fair value measurement of financial instruments to determine if a transfer among hierarchy levels is appropriate.

Financial assets and liabilities that we measure at fair value each period include our derivative instruments and equity investments related to our deferred compensation plan (see Note 5 and Note 8). Additionally, we measure at fair value once each year at December 31 the plan assets of our defined benefit pension and postretirement plans including the Salaried VEBA (see Note 5). In determining the fair value of the plan assets at an annual period end, we utilize primarily the results of valuations supplied by the investment advisors responsible for managing the assets of each plan, which we independently review for reasonableness. We record our remaining financial assets and liabilities at carrying value.

Goodwill is tested for impairment during the fourth quarter on an annual basis, as well as on an interim basis, as warranted, at the time of relevant events and changes in circumstances. Our policy around goodwill impairment testing permits us to perform a qualitative assessment or a quantitative goodwill impairment test. If a qualitative assessment is performed, we are not required to perform the quantitative goodwill impairment test unless we determine that, based on that qualitative assessment, it is more likely than not that our fair value is less than the carrying value. We performed our annual testing of goodwill impairment by applying the qualitative assessment as of October 1, 2024. For the current year evaluation, we assessed various assumptions, events and circumstances that would have affected the estimated fair value of the reporting unit under the qualitative assessment. The results of the qualitative assessment indicated that it is not more likely than not that the fair values of our reporting units were less than the carrying value.

Intangible asset fair values and useful lives are determined using the income approach valuation methodology. The income approach incorporates the use of cash flow projections and a discount rate that are developed using market participant-based assumptions. The cash flow projections are based on, among other factors, the expected future period of benefit of the asset, the various characteristics of the asset, long‑term forecasts of the business, market prices, projected cash flows and the rate used in discounting those cash flows. Intangible assets

with definite lives are initially recognized at fair value and subsequently amortized over the estimated useful lives to reflect the pattern in which the economic benefits of the intangible assets are consumed. In the event the pattern cannot be reliably determined, we use a straight-line amortization method. Whenever events or changes in circumstances indicate that the carrying amount of the intangible assets may not be recoverable, the intangible assets are reviewed for impairment. See Note 4 for discussion on goodwill and intangible assets.

For a majority of our remaining non-financial assets and liabilities, which include inventories, debt issuance costs, and property, plant and equipment, we are not required to measure their fair value on a recurring basis. However, if certain triggering events occur, an evaluation of the affected non-financial asset or liability will be required, which could result in a reduction to the carrying amount of such asset or liability. See “Property, Plant and Equipment, Net” below for a discussion of impairment charges on long-lived physical assets. See Note 9 for the fair value of our Long-term debt, net.

Government Grants. From time to time, we receive grants from certain governmental agencies such as states and municipalities. We recognize government grants when we have reasonable assurance that we will comply with any conditions attached to the grant and the grant will be received. Government grants related to property, plant and equipment are presented as a reduction to the related asset’s carrying amount. Grants related to compensation for expenses already incurred or for immediate financial support with no future related costs are recognized as income in the period in which they are receivable. The following table presents the total government assistance recognized during the year ended December 31, 2024 (in millions of dollars):

 

Grantor

 

Grant

 

Amount

 

 

Duration

 

Classification

Indiana Economic Development Corporation

 

IN EDGE Tax Credit

 

$

1.6

 

 

2021 - 2030

 

Cost of products sold, excluding depreciation and amortization

Total

 

 

 

$

1.6

 

 

 

 

 

To be eligible to receive and keep the full amount of the IN EDGE Tax Credit, we must achieve: (i) minimum cumulative expenditures towards capital expenditures and (ii) a minimum number of full-time employees.

Cash and Cash Equivalents. We consider only those short-term, highly liquid investments which, when purchased, have maturities of 90 days or less to be cash equivalents. Our cash equivalents consist primarily of funds in money market deposit accounts.

Restricted Cash. We are required to keep on deposit certain amounts that are pledged or held as collateral relating to workers’ compensation and other agreements. We account for such deposits as restricted cash (see Note 16). From time to time, such restricted funds could be returned to us or we could be required to pledge additional cash.

Trade Receivables and Allowance for Credit Losses. Trade receivables primarily consist of amounts billed to customers for products sold. Accounts receivable are generally due within 30 to 90 days. For the majority of our receivables, we establish an allowance for credit losses based upon collection experience and other factors including, but not limited to, customer credit ratings, bankruptcy filings, published or estimated credit default rates, age of receivables, expected loss rates, and collateral exposures. On certain other receivables where we are aware of a specific customer’s inability or reluctance to pay, an allowance for credit losses is established against amounts due, to reduce the net receivable balance to the amount we reasonably expect to collect. However, if circumstances change, our estimate of the recoverability of accounts receivable could be different. Circumstances that could affect our estimates include, but are not limited to, customer credit issues and general economic conditions. Accounts are written off once deemed to be uncollectible. Any subsequent cash collections relating to accounts that have been previously written off are typically recorded as a reduction to total bad debt expense in the period of payment. Write-offs for 2024, 2023, and 2022 were immaterial to our consolidated financial statements.

Inventories. Inventories are stated at the lower of cost or market value. Finished products, work-in-process, and raw material inventories are stated on the LIFO basis. At December 31, 2024 and December 31, 2023, the cost of our inventory on a FIFO basis, which approximates the current replacement cost, exceeded its stated LIFO value by $96.8 million and $56.0 million, respectively. Other inventories are stated on the FIFO basis and consist of operating supplies, which are materials and supplies to be consumed during the production process. Inventory costs consist of material, labor, and manufacturing overhead, including depreciation. Abnormal costs, such as idle facility expenses, freight, handling costs, and spoilage, are accounted for as current period charges. See Note 2 for the components of inventories.

Replacement Parts. Replacement parts consist of equipment spare parts, which are stated on the FIFO basis. Replacement parts are recorded within Prepaid expenses and other current assets or Other assets depending on whether the expected utilization of the replacement parts is to occur within the next 12 months.

Property, Plant and Equipment, Net. Property, plant and equipment, net, is recorded at cost and includes construction in progress (see Note 2). Interest related to the construction of qualifying assets is capitalized as part of the construction costs (see Note 9).

Depreciation is computed using the straight-line method at rates based on the estimated useful lives of the various classes of assets. Depreciable finance lease assets and leasehold improvements are amortized on a straight-line basis over the shorter of the estimated useful lives of the assets or the lease term. The estimated useful lives are as follows:

 

 

 

Range
(in years)

Land improvements

 

1-25

Buildings and leasehold improvements

 

2-45

Machinery and equipment

 

1-22

Depreciable finance lease assets

 

2-120

 

Depreciation expense is included in Depreciation and amortization within our Statements of Consolidated Income (Loss).

Property, plant and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset or group of assets may not be recoverable. We regularly assess whether events and circumstances with the potential to trigger impairment have occurred and rely on a number of factors, including operating results, business plans, economic projections, and anticipated future cash flow, to make such assessments. We use an estimate of the future undiscounted cash flows of the related asset or asset group over the estimated remaining life of such asset or asset group in measuring whether the asset or asset group is recoverable.

We recorded an impairment charge of $0.4 million on land classified as held for sale during 2024. There were no impairment charges in 2023 and 2022. Asset impairment charges are included in Other operating charges, net, in our Statements of Consolidated Income (Loss).

We classify assets as held for sale only when an asset is being actively marketed and expected to sell within 12 months. Assets held for sale are initially measured at the lesser of the assets’ carrying amount and the fair value less costs to sell.

Leases. We determine whether an agreement is a lease at inception. We have operating and finance leases for equipment and real estate that primarily have fixed lease payments. For purposes of calculating lease liabilities, options to extend or terminate a lease are included within the lease term when it is reasonably certain that we will exercise such options. Short-term leases with an initial term of 12 months or less are not recorded on our Consolidated Balance Sheets.

As most of our leases do not provide an implicit rate, we use information available at the lease commencement date in determining an incremental borrowing rate when calculating our right-of-use lease assets and liabilities. In determining the inputs to the incremental borrowing rate calculation, we make judgments about the value of the leased asset, our credit rating, and the lease term, including the probability of our exercising options to extend or terminate the underlying lease. Additionally, we make judgments around contractual asset substitution rights in determining whether a contract contains a lease.

We have lease agreements with lease and non-lease components, which are generally accounted for separately. These non-lease components include items such as common area maintenance, taxes, and insurance for our real estate leases, as well as maintenance charges related to our equipment leases. We have, however, applied the practical expedient within ASC No. 2016-02, Leases (Topic 842): Amendments to the Financial Accounting Standards Board Accounting Standards Codification, to not separate lease and non-lease components to our embedded supply system equipment leases and have therefore accounted for both lease and non‑lease components in determining the lease assets and liabilities.

Many of our equipment leases contain clauses that require us to return the equipment with certain functionality intact. We account for these costs as residual value guarantees when the guarantee becomes probable of being owed. Our lease agreements do not contain any material restrictive covenants.

Derivative Financial Instruments. Consistent with guidelines established by management and approved by our Board of Directors, we use derivative financial instruments to mitigate our exposure to changes in the market price of aluminum, certain alloying metals, energy, and foreign currency exchange rates. We do not use derivative financial instruments for trading or other speculative purposes. Hedging transactions are executed centrally on behalf of all of our operations to minimize transaction costs, monitor consolidated net exposures, and allow for increased responsiveness to changes in market factors.

We reflect the fair value of all of our derivative instruments on our Consolidated Balance Sheets. The fair value of hedges settling within one year is included in Prepaid expenses and other current assets or Other accrued liabilities. The fair value of hedges settling beyond one year is included in Other assets or Long-term liabilities. Cash flows related to all of our derivative instruments are reported in our Statements of Consolidated Cash Flows within the same category as the items being hedged. See Note 8 for additional information on our derivative financial instruments.

Self-Insurance of Workers’ Compensation and Employee Healthcare Liabilities. We self-insure the majority of the costs of workers’ compensation benefits and employee healthcare benefits and rely on insurance coverage to protect us from large losses on individual claims. Workers’ compensation liabilities are based on a combination of estimates for incurred-but-not-reported claims and the ultimate expense of incurred claims. Such estimates are based on judgment, using our historical claims data and information and analysis provided by actuarial and claims advisors, our insurance carriers, and other professionals. Accrued liabilities for employee healthcare benefits, which are estimates of unpaid incurred medical and prescription drug costs as provided by our healthcare administrators, were $7.8 million and $7.7 million at December 31, 2024 and December 31, 2023, respectively.

Debt Issuance Costs. Costs incurred in connection with debt financing are deferred and amortized over the estimated term of the related borrowing. Such amortization is included in Interest expense in our Statements of Consolidated Income (Loss). Unamortized issuance costs are presented within Long-term debt, net on our Consolidated Balance Sheets (see Note 9).

Conditional Asset Retirement Obligations (“CAROs”). We have CAROs at several of our manufacturing facilities. Our CAROs can be separated into two primary categories: (i) legal obligations related to the removal and disposal of asbestos and (ii) CAROs related to future lease terminations. The majority of our CAROs relate to the first category and consist of incremental costs that would be associated with the removal and disposal of asbestos (all of which is believed to be fully contained and encapsulated within walls, floors, roof, piping, or equipment insulation) of certain of our older facilities if such facilities were to undergo major renovation or be demolished. We estimate incremental costs for special handling, removal and disposal costs of materials that may or will give rise to CAROs and then discount the expected costs back to the current year using a credit-adjusted, risk-free rate. When it is unclear when or if CAROs will be triggered, we use probability weighting for possible timing scenarios to determine the probability-weighted liability amounts that should be recognized in our consolidated financial statements (see Note 10).

Environmental Contingencies. With respect to environmental loss contingencies, we record a loss contingency whenever a contingency is probable and reasonably estimable (see Note 10). Accruals for estimated losses from environmental remediation obligations are generally recognized no later than the completion of the remedial feasibility study. Such accruals are adjusted as information develops or circumstances change. Costs of future expenditures for environmental remediation obligations are not discounted to their present value. Accruals for expected environmental costs are included in Other accrued liabilities or Long-term liabilities, as appropriate (see Note 2). Environmental expense relating to continuing operations is included in COGS in our Statements of Consolidated Income (Loss). Environmental expense relating to non-operating locations is included in Selling, general, administrative, research and development (“SG&A and R&D”) in our Statements of Consolidated Income (Loss).

Revenue Recognition. We recognize revenue as we fulfill our performance obligations and transfer control of products to our customers. For products that have an alternative use and/or for which we do not have an enforceable right to payment (including a reasonable profit) during the production process, we recognize revenue at a point in time. For products that have no alternative use and for which we have an enforceable right to payment (including a reasonable profit) throughout the production process, we recognize revenue over time. In general, revenue recognized over time primarily relates to our Aero/HS Products and our Automotive Extrusions with the remainder of our products recognized at a point in time. In limited circumstances, we have concluded that we are an agent in certain Packaging end market arrangements. For these transactions, revenue has been recognized on a net basis.

For the majority of our business, contracts with customers begin when we acknowledge a purchase order for a specific customer order of product to be delivered in the near term. These purchase orders are short-term in nature, although they may reference a longer term “blanket purchase order” or a “terms and conditions” agreement, both of which may span multiple years. For revenue recognized at a point in time, transfer of control usually occurs upon shipment or upon customer receipt of the product, depending on shipping terms. For contracts recognized over time, control transfer occurs incrementally during our production process as progress is made on fulfilling the performance obligation. We use the input method of determining our progress, capturing direct costs beginning at the point that billet or cast ingot is introduced into production at either the extrusion phase or the rolling phase, respectively. We believe the input method more accurately reflects the transfer of control as it represents the best information available of work completed to date for which we have an enforceable right to payment. For products in production, we recognize revenue using estimates of the cost incurred to date plus a reasonable margin. As the duration of our contracts for accounting purposes is typically less than one year, we do not present quantitative information about the aggregate transaction price allocated to unsatisfied performance obligations at the end of the reporting period.

We adjust the amount of revenue recognized on all products, regardless of timing of revenue recognition, for variable price consideration, which could include metal market price adjustments, volume rebates and sales discounts. We estimate rebate and discount values based on forecasted order data and historical payment trends for specific customers, adjusted as necessary at each reporting period. Accounts receivable is recorded when our right to consideration becomes unconditional. We do not adjust the promised amount of consideration for the effects of a significant financing component as we do not expect the period between the transfer of control of products to our customers and receipt of payment will be greater than one year.

Contract assets primarily relate to our enforceable right to consideration for work completed but not billed at the reporting date on contracts for products recognized over time. Contract assets also include amounts related to our contractual right to consideration for finished goods recognized over time that were in transit as of period end.

Incremental Costs of Obtaining a Contract. We expense the costs of obtaining a contract as incurred as the amortization period of the asset that we otherwise would have recognized is one year or less.

Shipping and Handling Activities. We account for shipping and handling activities that occur after the customer has obtained control of a product as fulfillment activities (i.e., an expense) rather than as a promised service (i.e., a revenue element).

Advertising Costs. Advertising costs, which are included in SG&A and R&D, are expensed as incurred. Advertising costs for 2024 and 2023 were $0.4 million and $0.1 million, respectively. We had no advertising costs in 2022.

Research and Development Costs. Research and development costs, which are included in SG&A and R&D, are expensed as incurred. Research and development costs, inclusive of personnel costs, for 2024, 2023, and 2022 were $12.0 million, $11.1 million and $9.3 million, respectively.

Stock-Based Compensation. Stock-based compensation in the form of service-based awards is provided to executive officers, certain employees and non-employee directors and is accounted for at fair value. We measure the cost of services received in exchange for an award of equity instruments based on the grant-date fair value of the award and the number of awards expected to ultimately vest. The grant-date fair value is determined based on the stock price on the date of grant, adjusted for expected dividends or dividend equivalents to be paid during the vesting period.

We also grant performance-based awards to executive officers and other key employees. The methodology used to value these performance-based awards is based on the nature of the performance conditions within those awards. Awards that are subject to performance conditions pertaining to total shareholder return (market-based awards) are valued on the date of grant using a Monte Carlo valuation model. The key assumptions in applying this model are an expected volatility and a risk-free interest rate. Awards with certain other performance conditions (non-market-based awards) are valued based on our stock price at the date of grant. Our non‑market-based awards have performance conditions pertaining to our cost performance and Adjusted EBITDA margin performance, which is measured by our Adjusted EBITDA as a percentage of Conversion Revenue, which is Net sales less the Hedged Cost of Alloyed Metal. As used in this discussion, “Hedged Cost of Alloyed Metal” is the cost of aluminum at the average MWTP plus the cost of alloying elements and any realized gains and/or losses on settled hedges related to the metal sold in the referenced period. Holders of performance-based awards receive a one-time payment at the time of issuance of vested shares based on the total dividends they would have received if the vested shares had been held of record from the date of grant through the date of issuance. See Note 7 for more information on our stock-based compensation.

The cost of service-based awards, including time-vested restricted stock and performance shares, is recognized as an expense over the requisite service period of the award on a straight-line basis. Adjustments to expense related to forfeitures are recorded in the period in which they occur. We recognize stock-based compensation expense for market-based awards if the requisite service period is rendered, even if the market condition is never satisfied. For performance shares with performance conditions pertaining to our cost performance and Adjusted EBITDA margin performance, the related expense is updated quarterly by adjusting the estimated number of shares expected to vest based on the most probable outcome of the performance condition (see Note 7).

Adoption of New Accounting Pronouncements

Segment Reporting. In November 2023, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2023-07 (“ASU 2023-07”), Improvements to Reportable Segment Disclosures. The guidance primarily requires enhanced disclosures about significant segment expenses. All disclosure requirements under ASU 2023-07 and existing segment disclosures in ASC 280, Segment Reporting are also

required for public entities with a single reportable segment. There were no material impacts on our consolidated financial statements resulting from our adoption of ASU 2023-07. See Note 17 for the required disclosures related to our adoption of ASU 2023-07.

Accounting Pronouncements Issued But Not Yet Adopted

Disclosure Improvements. In October 2023, the FASB issued ASU No. 2023-06 (“ASU 2023-06”), Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative. The guidance amends GAAP to reflect updates and simplifications to certain disclosure requirements referred to the FASB by the SEC. The amendments in ASU 2023-06 will become effective on the date which the SEC’s removal of the related disclosure becomes effective. If by June 30, 2027, the SEC does not remove the related disclosure, the pending amendment will be removed from ASC 2023-06 and it will not be effective. We do not expect this ASU to have a material impact on our consolidated financial statements.

Income Taxes. In December 2023, the FASB issued ASU No. 2023-09 (“ASU 2023-09”), Improvements to Income Tax Disclosures. The guidance is primarily intended to improve income tax disclosure requirements by requiring (i) consistent categories and greater disaggregation of information in the rate reconciliation and (ii) the disaggregation of income taxes paid by jurisdiction. The guidance makes several other changes to the income tax disclosure requirements. The amendments in ASU 2023-09 are effective for fiscal years beginning after December 15, 2024, with early adoption permitted, and is required to be applied prospectively with the option of retrospective application. We plan to adopt the provisions of ASU 2023-09 in the fourth quarter of fiscal 2025 and do not expect this ASU to have a material impact on our consolidated financial statements.

Disaggregation of Income Statement Expenses. In November 2024, the FASB issued ASU No. 2024-03 (“ASU 2024-03”), Disaggregation of Income Statement Expenses. The guidance requires additional, disaggregated disclosure about certain income statement expense line items. The amendments in ASU 2024-03 are effective for annual reporting periods beginning after December 15, 2026 and interim reporting periods beginning after December 15, 2027, with early adoption permitted, and is required to be applied prospectively with the option of retrospective application. We plan to adopt the provisions of ASU 2024-03 in the fourth quarter of fiscal 2027 and continue to evaluate the disclosure requirements related to the new standard.
v3.25.0.1
Supplemental Balance Sheet Information
 12 Months Ended
Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Supplemental Balance Sheet Information

2. Supplemental Balance Sheet Information

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

 

 

(In millions of dollars)

 

Trade Receivables, Net

 

 

 

 

 

 

Billed trade receivables

 

$

320.5

 

 

$

325.8

 

Allowance for doubtful receivables

 

 

(0.8

)

 

 

(0.6

)

Trade receivables, net

 

$

319.7

 

 

$

325.2

 

 

 

 

 

 

 

Inventories

 

 

 

 

 

 

Finished products

 

$

103.7

 

 

$

89.3

 

Work-in-process

 

 

193.3

 

 

 

210.8

 

Raw materials

 

 

192.8

 

 

 

161.5

 

Operating supplies

 

 

14.1

 

 

 

15.6

 

Inventories

 

$

503.9

 

 

$

477.2

 

 

 

 

 

 

 

Property, Plant and Equipment, Net

 

 

 

 

 

 

Land and improvements

 

$

37.2

 

 

$

38.0

 

Buildings and leasehold improvements

 

 

256.3

 

 

 

238.4

 

Machinery and equipment 1

 

 

1,337.4

 

 

 

1,265.3

 

Construction in progress

 

 

297.5

 

 

 

173.7

 

Property, plant and equipment, gross

 

 

1,928.4

 

 

 

1,715.4

 

Accumulated depreciation and amortization

 

 

(767.5

)

 

 

(663.7

)

Land held for sale

 

 

0.3

 

 

 

0.4

 

Property, plant and equipment, net

 

$

1,161.2

 

 

$

1,052.1

 

 

 

 

 

 

 

Other Assets

 

 

 

 

 

 

Assets to be conveyed associated with Warrick acquisition 1

 

$

18.3

 

 

$

56.8

 

Restricted cash – Note 16

 

 

19.5

 

 

 

18.3

 

Long-term replacement parts

 

 

18.3

 

 

 

16.7

 

Other

 

 

22.5

 

 

 

25.9

 

Other assets

 

$

78.6

 

 

$

117.7

 

.

 

 

 

 

 

 

Other Accrued Liabilities

 

 

 

 

 

 

Uncleared cash disbursements

 

$

24.5

 

 

$

15.7

 

Accrued income taxes and other taxes payable

 

 

11.2

 

 

 

9.5

 

Accrued annual contribution to Salaried VEBA – Note 5

 

 

0.7

 

 

 

1.1

 

Accrued interest

 

 

9.9

 

 

 

9.9

 

Short-term environmental accrual – Note 10

 

 

0.7

 

 

 

2.8

 

Current operating lease liabilities – Note 3

 

 

6.3

 

 

 

8.0

 

Current finance lease liabilities – Note 3

 

 

2.4

 

 

 

2.1

 

Current deferred compensation plan liabilities - Note 5

 

 

6.7

 

 

 

0.4

 

Other – Note 8

 

 

17.0

 

 

 

14.8

 

Other accrued liabilities

 

$

79.4

 

 

$

64.3

 

 

 

 

 

 

 

Long-Term Liabilities

 

 

 

 

 

 

Workers' compensation accrual

 

$

26.8

 

 

$

29.9

 

Long-term environmental accrual – Note 10

 

 

17.7

 

 

 

14.2

 

Other long-term liabilities

 

 

39.5

 

 

 

37.6

 

Long-term liabilities

 

$

84.0

 

 

$

81.7

 

 

1.
During the year ended December 31, 2024, $38.5 million of certain assets associated with our acquisition of Warrick were conveyed to us and placed in service. At December 31, 2024, such assets are presented within Machinery and equipment.
v3.25.0.1
Leases
 12 Months Ended
Dec. 31, 2024
Leases [Abstract]  
Leases

3. Leases

The following table summarizes key finance and operating lease terms and discount rates:

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

Weighted-average remaining lease term (in years):

 

 

 

 

 

 

Finance leases

 

 

36.9

 

 

 

38.8

 

Operating leases

 

 

8.9

 

 

 

8.9

 

Weighted-average discount rate:

 

 

 

 

 

 

Finance leases

 

 

5.40

%

 

 

5.31

%

Operating leases

 

 

4.69

%

 

 

4.35

%

 

The following table summarizes the classification of lease assets and lease liabilities on our Consolidated Balance Sheets (in millions of dollars):

 

 

 

 

 

As of December 31,

 

Description

 

Classification

 

2024

 

 

2023

 

Operating lease assets

 

Operating lease assets

 

$

27.2

 

 

$

32.6

 

Finance lease assets

 

Property, plant and equipment, net

 

$

14.8

 

 

$

14.3

 

 

 

 

 

 

 

 

 

 

Current operating lease liabilities

 

Other accrued liabilities

 

$

6.3

 

 

$

8.0

 

Non-current operating lease liabilities

 

Long-term portion of operating lease liabilities

 

$

25.2

 

 

$

29.2

 

Total operating lease liabilities

 

 

 

$

31.5

 

 

$

37.2

 

 

 

 

 

 

 

 

 

 

Current finance lease liabilities

 

Other accrued liabilities

 

$

2.4

 

 

$

2.1

 

Non-current finance lease liabilities

 

Long-term liabilities

 

$

13.0

 

 

$

12.9

 

Total finance lease liabilities

 

 

 

$

15.4

 

 

$

15.0

 

 

The following table summarizes the components of lease cost in our Statements of Consolidated Income (Loss) (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Operating lease cost

 

$

10.2

 

 

$

11.6

 

 

$

12.1

 

Short-term lease cost

 

 

4.0

 

 

 

4.3

 

 

 

4.3

 

Finance lease cost:

 

 

 

 

 

 

 

 

 

Amortization of leased assets

 

 

2.4

 

 

 

2.4

 

 

 

2.5

 

Interest on lease liabilities

 

 

0.8

 

 

 

0.7

 

 

 

0.3

 

Total lease cost

 

$

17.4

 

 

$

19.0

 

 

$

19.2

 

 

The following table presents the maturity of our lease liabilities as of December 31, 2024 (in millions of dollars):

 

 

 

Finance Leases

 

 

Operating Leases

 

2025

 

$

3.1

 

 

$

7.6

 

2026

 

 

2.5

 

 

 

5.1

 

2027

 

 

1.5

 

 

 

4.2

 

2028

 

 

1.0

 

 

 

3.8

 

2029

 

 

0.7

 

 

 

3.7

 

Thereafter

 

 

26.3

 

 

 

15.6

 

Total minimum lease payments

 

$

35.1

 

 

$

40.0

 

Less: interest

 

 

(19.7

)

 

 

(8.5

)

Present value

 

$

15.4

 

 

$

31.5

 
v3.25.0.1
Goodwill and Intangible Assets
 12 Months Ended
Dec. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]  
Goodwill and Intangible Assets

4. Goodwill and Intangible Assets

Goodwill. We identified no indicators of goodwill impairment during the years ended December 31, 2024 and December 31, 2023. During the year ended December 31, 2022, we recognized an impairment charge of $20.5 million within Operating income in the Statements of Consolidated Income (Loss) related to Warrick. As goodwill is deductible for tax purposes, the deferred tax effects were included in the impairment charge and income tax provision.

The following table presents the changes in the carrying value of our goodwill (in millions of dollars):

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

Gross carrying value1

 

$

57.7

 

 

$

57.7

 

Accumulated impairment loss1

 

 

(38.9

)

 

 

(38.9

)

Net carrying value

 

$

18.8

 

 

$

18.8

 
1.
The gross carrying value and accumulated impairment loss excludes $25.2 million of goodwill recorded in conjunction with our acquisition of IMT.

Intangible Assets. The following table presents the gross carrying amount and accumulated amortization by major intangible asset class (in millions of dollars, except amortization periods):

 

 

 

Weighted-
Average
Amortization
Period
(in years)

 

 

Gross
Amount

 

 

Accumulated
Amortization

 

 

Intangible
Assets, Net

 

As of December 31, 2024

 

 

 

 

 

 

 

 

 

 

 

 

Customer relationships

 

 

19

 

 

$

68.1

 

 

$

(30.3

)

 

$

37.8

 

Trade name

 

 

10

 

 

 

2.4

 

 

 

(1.5

)

 

 

0.9

 

Non-compete agreement

 

 

5

 

 

 

5.4

 

 

 

(5.4

)

 

 

—

 

Favorable lease contracts

 

 

120

 

 

 

7.0

 

 

 

(0.2

)

 

 

6.8

 

Total

 

 

26

 

 

$

82.9

 

 

$

(37.4

)

 

$

45.5

 

As of December 31, 2023

 

 

 

 

 

 

 

 

 

 

 

 

Customer relationships

 

 

19

 

 

$

68.1

 

 

$

(26.1

)

 

$

42.0

 

Trade name

 

 

10

 

 

 

2.4

 

 

 

(1.2

)

 

 

1.2

 

Non-compete agreement

 

 

5

 

 

 

5.4

 

 

 

(5.4

)

 

 

—

 

Favorable lease contracts

 

 

120

 

 

 

7.0

 

 

 

(0.2

)

 

 

6.8

 

Total

 

 

26

 

 

$

82.9

 

 

$

(32.9

)

 

$

50.0

 

We identified no indicators of impairment associated with our intangible assets during the years ended December 31, 2024 and December 31, 2023. During the year ended December 31, 2022, we impaired the remaining book value of our favorable commodity contracts intangible asset as the supplier associated with the intangible asset ceased all deliveries of magnesium to us and provided no indication of

when or if deliveries would resume over the remainder of the contract. The impairment charge of $3.1 million was included within Other operating charges, net, in our Statements of Consolidated Income (Loss).

Amortization expense relating to definite-lived intangible assets was $4.5 million, $5.3 million and $9.3 million for 2024, 2023, and 2022, respectively. The following table presents the expected amortization of intangible assets for each of the next five calendar years and thereafter as of December 31, 2024 (in millions of dollars):

 

2025

 

$

4.5

 

2026

 

 

4.5

 

2027

 

 

4.5

 

2028

 

 

4.4

 

2029

 

 

4.1

 

Thereafter

 

 

23.5

 

Total

 

$

45.5

 
v3.25.0.1
Employee Benefits
 12 Months Ended
Dec. 31, 2024
Retirement Benefits [Abstract]  
Employee Benefits

5. Employee Benefits

Defined Contribution Plans

We sponsor defined contribution 401(k) savings plans for certain hourly and salaried employees. Employees may contribute a portion of their compensation to the plans, and we match a specified percentage of these contributions in equivalent form of the investments elected by the employee. In addition, we make fixed annual contributions for certain hourly and salaried employees in varying amounts depending on hire date.

Deferred Compensation Plan

We sponsor a non-qualified, unfunded, unsecured plan of deferred compensation for certain employees who would otherwise suffer a loss of benefits under our defined contribution plan as a result of the limitations imposed by the Internal Revenue Code of 1986. Despite the plan being an unfunded plan, we make an annual contribution to a rabbi trust to fulfill future funding obligations, as contemplated by the terms of the plan. The assets in the trust are held in various investment funds at certain registered investment companies (see discussion below in “Fair Value of Plan Assets”) and are at all times subject to the claims of our general creditors. No participant has a claim to any assets of the trust; however, participants are eligible to receive distributions from the trust subject to vesting and other eligibility requirements. Offsetting liabilities relating to the deferred compensation plan are included within Other accrued liabilities and Long-term liabilities. Assets in the trust are accounted for as equity investments with changes in fair value recorded within Other income, net (see Note 13).

Other Benefits

We provide other benefits for certain members of senior management, including certain of our named executive officers, related to terminations of employment in specified circumstances, including in connection with a change in control, by us without cause and by the executive officer with good reason.

Defined Benefit Plans

Pension. We sponsor defined benefit pension plans for certain hourly bargaining unit employees and salaried employees. Pension benefits generally depend on length of service, job grade, and remuneration. Substantially all benefits are paid through pension trusts that are sufficiently funded to ensure that all plans can pay benefits to retirees as they become due. We use a December 31 measurement date for our pension plans.

OPEB. We sponsor an OPEB plan covering certain eligible retirees. Generally, the medical plans are unfunded and pay a percentage of medical expenses, reduced by deductibles and other coverage. Life insurance benefits are generally provided by insurance contracts. We use a December 31 measurement date for our OPEB plan.

Salaried VEBA Postretirement Obligation. Certain retirees who retired prior to 2004 and certain employees who were hired prior to February 2002 and have subsequently retired or will retire with the requisite age and service, along with their surviving spouses and eligible

dependents, are eligible to participate in a Salaried VEBA. The accumulated postretirement benefit obligation (“APBO”) for the Salaried VEBA was computed based on the level of benefits being provided. Since the Salaried VEBA pays out a fixed annual amount to its participants, no future cost trend rate increase was assumed in computing the APBO for the Salaried VEBA.

We have an ongoing obligation with no express termination date to make variable cash contributions up to a maximum of $2.9 million annually to the Salaried VEBA. The Salaried VEBA assets are invested in various managed funds based on information we received from the trustee of the Salaried VEBA. Our variable payment, if any, is treated as a funding/contribution policy and not counted as a Salaried VEBA asset at the accrual date for actuarial purposes. We determined that in the first quarter of 2025 we will pay approximately $0.7 million with respect to 2024. During the first quarter of 2024, we paid $1.1 million with respect to 2023. Such amounts were recorded within Other accrued liabilities (see Note 2). We account for the Salaried VEBA as a defined benefit plan in our financial statements using a December 31 measurement date.

Key Assumptions. The following table presents the weighted average assumptions used to determine benefit obligations:

 

 

 

Pension Plans1

 

 

OPEB

 

 

Salaried VEBA

 

 

 

As of December 31,

 

 

As of December 31,

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

 

2024

 

 

2023

 

 

2024

 

 

2023

 

Discount rate

 

 

5.54

%

 

 

4.95

%

 

 

5.48

%

 

 

4.92

%

 

 

5.40

%

 

 

4.89

%

Rate of compensation increase

 

 

2.56

%

 

 

2.63

%

 

 

—

%

 

 

—

%

 

 

—

%

 

 

—

%

 

1.
Assumptions for our pension plans are weighted based on the total benefit obligations of each.

The following table presents the weighted average assumptions used to determine net periodic postretirement and postemployment benefit cost:

 

 

 

Pension Plans1

 

 

OPEB

 

 

Salaried VEBA

 

 

 

Year Ended December 31,

 

 

Year Ended December 31,

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

 

2024

 

 

2023

 

 

2022

 

 

2024

 

 

2023

 

 

2022

 

Discount rate

 

 

5.00

%

 

 

5.19

%

 

 

2.90

%

 

 

4.92

%

 

 

5.14

%

 

 

2.64

%

 

 

4.89

%

 

 

5.10

%

 

 

2.49

%

Expected long-term return on plan assets2

 

 

6.31

%

 

 

6.33

%

 

 

6.02

%

 

 

—

%

 

 

—

%

 

 

—

%

 

 

5.75

%

 

 

5.75

%

 

 

5.50

%

Rate of compensation increase

 

 

2.56

%

 

 

2.63

%

 

 

2.69

%

 

 

—

%

 

 

—

%

 

 

—

%

 

 

—

%

 

 

—

%

 

 

—

%

 

1.
Assumptions for our pension plans are weighted based on the total benefit obligations of each.
2.
The expected long-term rate of return assumption for the Salaried VEBA is based on the targeted investment portfolios provided to us by the trustee of the Salaried VEBA.

In measuring the expected cost of benefits covered by our OPEB plan, we estimate a healthcare cost trend rate representing the annual rates of change in the costs of the healthcare benefits currently provided by the OPEB plan. The 2024 actuarial valuation assumed a 7.7% annual rate of increase in the per capita cost of covered healthcare claims with the rate decreasing until reaching 4.5% in 2038.

Benefit Obligations and Funded Status. The following table presents the benefit obligations and funded status of our pension plans, OPEB, and the Salaried VEBA and the corresponding amounts that are included in our Consolidated Balance Sheets (in millions of dollars):

 

 

 

Pension Plans

 

 

OPEB

 

 

Salaried VEBA

 

 

 

As of December 31,

 

 

As of December 31,

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

 

2024

 

 

2023

 

 

2024

 

 

2023

 

Change in benefit obligation:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Obligation at beginning of year

 

$

30.5

 

 

$

18.8

 

 

$

68.8

 

 

$

66.4

 

 

$

46.9

 

 

$

58.9

 

Foreign currency translation adjustment

 

 

(0.5

)

 

 

0.2

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Service cost

 

 

3.6

 

 

 

3.8

 

 

 

1.1

 

 

 

1.1

 

 

 

—

 

 

 

—

 

Interest cost

 

 

1.6

 

 

 

1.3

 

 

 

3.3

 

 

 

3.4

 

 

 

2.2

 

 

 

2.9

 

Prior service cost (credit)1

 

 

2.2

 

 

 

6.6

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(8.8

)

Actuarial (gain) loss2

 

 

(1.6

)

 

 

0.2

 

 

 

(6.8

)

 

 

(0.7

)

 

 

(1.4

)

 

 

0.4

 

Plan participants contributions

 

 

0.1

 

 

 

0.1

 

 

 

0.2

 

 

 

0.1

 

 

 

—

 

 

 

—

 

Benefits paid

 

 

(0.7

)

 

 

(0.5

)

 

 

(1.9

)

 

 

(1.5

)

 

 

(4.8

)

 

 

(6.5

)

Settlements3

 

 

(4.5

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Obligation at end of year4

 

 

30.7

 

 

 

30.5

 

 

 

64.7

 

 

 

68.8

 

 

 

42.9

 

 

 

46.9

 

Change in plan assets:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fair market value of plan assets at beginning of year

 

 

20.5

 

 

 

14.9

 

 

 

—

 

 

 

—

 

 

 

43.1

 

 

 

42.4

 

Foreign currency translation adjustment

 

 

0.3

 

 

 

0.2

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Actual return on assets

 

 

0.9

 

 

 

1.4

 

 

 

—

 

 

 

—

 

 

 

3.9

 

 

 

6.1

 

Plan participants contributions

 

 

0.1

 

 

 

0.1

 

 

 

0.2

 

 

 

0.1

 

 

 

—

 

 

 

—

 

Company contributions

 

 

5.9

 

 

 

4.4

 

 

 

1.7

 

 

 

1.4

 

 

 

0.7

 

 

 

1.1

 

Benefits paid

 

 

(0.7

)

 

 

(0.5

)

 

 

(1.9

)

 

 

(1.5

)

 

 

(4.8

)

 

 

(6.5

)

Settlements3

 

 

(4.5

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Fair market value of plan assets at end of year

 

 

22.5

 

 

 

20.5

 

 

 

—

 

 

 

—

 

 

 

42.9

 

 

 

43.1

 

Net funded status5

 

$

(8.2

)

 

$

(10.0

)

 

$

(64.7

)

 

$

(68.8

)

 

$

—

 

 

$

(3.8

)

Cumulative gain (loss) recognized in Accumulated other comprehensive income:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Accumulated net actuarial gain

 

$

4.2

 

 

$

1.3

 

 

$

23.1

 

 

$

17.4

 

 

$

8.2

 

 

$

5.2

 

Prior service cost

 

 

(7.6

)

 

 

(6.1

)

 

 

—

 

 

 

—

 

 

 

(14.3

)

 

 

(16.0

)

Total

 

$

(3.4

)

 

$

(4.8

)

 

$

23.1

 

 

$

17.4

 

 

$

(6.1

)

 

$

(10.8

)

 

1.
The prior service cost relating to our pension plans in 2024 resulted from an amendment to the Kaiser Aluminum Warrick pension plan clarifying certain plan provisions going back to the date of our acquisition of Warrick. The prior service cost relating to our pension plans in 2023 resulted from a new four-year collective bargaining agreement with the USW Local 104. In connection with the agreement, we amended the Kaiser Aluminum Warrick pension plan to increase certain pension benefits for covered plan participants. The prior service credit relating to the Salaried VEBA in 2023 resulted from a decrease in the annual healthcare reimbursement benefit for plan participants.
2.
The actuarial gain relating to our pension plans in 2024 was comprised of a $2.2 million gain due to a change in the discount rate, partially offset by a $0.3 million loss due to changes in census information and a $0.3 million loss recognized in conjunction with a group annuity purchase. The actuarial loss relating to our pension plans in 2023 was comprised of a $0.5 million loss due to a change in the discount rate and a $0.3 million gain due to changes in census information. The actuarial gain relating to the OPEB in 2024 was comprised of a $6.5 million gain due to changes in census information, a $3.3 million gain due to a change in the discount rate, a $3.2 million gain due to a change in morbidity assumptions, a $3.3 million loss due to a change in the trend rate assumption, and a $2.9 million loss due to a change in the projected depletion year. The actuarial gain relating to the OPEB in 2023 was comprised of a $2.7 million gain due to a change in the projected depletion year, a $2.5 million gain due to changes in census information, a $3.1 million loss due to a change in the trend rate assumption, and a $1.4 million loss due to a change in the discount rate. The actuarial gain relating to the Salaried VEBA in 2024 was comprised of a $1.4 million gain due to a change in the discount rate, a $0.1 million gain due to changes in census information, and a $0.1 million loss due to a change in the trend rate assumption.
The actuarial loss relating to the Salaried VEBA in 2023 was comprised of a $0.7 million loss due to a change in the discount rate and a $0.3 million gain due to changes in census information.
3.
In the fourth quarter of 2024, we entered into a group annuity purchase agreement under which approximately $4.5 million of obligations for certain participants of the Kaiser Aluminum Canada Limited Retirement Plan for Salaried Employees were transferred to an insurance company. The annuitization was funded through existing plan assets and does not change the amount of the monthly pension benefits received by the affected participants.
4.
For the pension plans, the benefit obligation is the projected benefit obligation. For the Salaried VEBA and OPEB, the benefit obligation is the APBO.
5.
At December 31, 2024, Net funded status relating to the pension plans consisted of $1.6 million within Other assets and $9.8 million within Pension and OPEB on our Consolidated Balance Sheets. At December 31, 2023, Net funded status relating to the pension plans consisted of $1.3 million within Other assets and $11.3 million within Pension and OPEB on our Consolidated Balance Sheets. Of the Net funded status relating to the OPEB at December 31, 2024, $3.1 million was included within Accrued salaries, wages and related expenses and $61.6 million was included within Pension and OPEB on our Consolidated Balance Sheets. Of the Net funded status relating to the OPEB at December 31, 2023, $3.3 million was included within Accrued salaries, wages and related expenses and $65.5 million was included within Pension and OPEB on our Consolidated Balance Sheets. Net funded status relating to the Salaried VEBA at December 31, 2024 and December 31, 2023 was included within Net liabilities of Salaried VEBA on our Consolidated Balance Sheets.

The accumulated benefit obligation for the pension plans was $29.8 million and $29.6 million at December 31, 2024 and December 31, 2023, respectively. We expect to contribute $4.5 million to the pension plans in 2025.

The following table presents the net benefits expected to be paid (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2025

 

 

2026

 

 

2027

 

 

2028

 

 

2029

 

 

2030-2034

 

Pension benefit payments

 

$

0.7

 

 

$

0.9

 

 

$

1.1

 

 

$

1.3

 

 

$

1.7

 

 

$

11.7

 

Salaried VEBA benefit payments1

 

 

5.3

 

 

 

5.1

 

 

 

4.9

 

 

 

4.6

 

 

 

4.3

 

 

 

16.9

 

OPEB payments

 

 

3.1

 

 

 

3.8

 

 

 

4.4

 

 

 

5.1

 

 

 

5.8

 

 

 

34.8

 

Total

 

$

9.1

 

 

$

9.8

 

 

$

10.4

 

 

$

11.0

 

 

$

11.8

 

 

$

63.4

 

 

1.
Such amounts are based on benefit amounts and certain key assumptions obtained from the Salaried VEBA trustees and will be paid out of the Salaried VEBA plan assets. We have an ongoing obligation to make variable cash contributions to the Salaried VEBA, up to a maximum of $2.9 million annually based on our cash flow.

 

Plan Assets. The fundamental goal underlying our pension plan investment policy is to ensure that the assets of the plans are invested in a prudent manner to earn a rate of return over time to meet the obligations of the plans as these obligations come due. Risk management practices include diversification across asset classes and periodic rebalancing toward established asset allocation targets. Our investment policy permits variances from the targets within certain parameters.

 

The following table presents the weighted-average target and actual asset class allocations for our pension plans:

 

Asset class

 

2024 Target allocation

 

As of December 31, 2024

Equities

 

56%

 

55%

Fixed income

 

38%

 

38%

Real estate investments

 

5%

 

6%

Cash and short-term investments

 

1%

 

1%

 

Fair Value of Plan Assets. The plan assets of our pension plans and the Salaried VEBA are measured annually on December 31 and reflected in our Consolidated Balance Sheets at fair value. In determining the fair value of the plan assets at an annual period end, we utilize primarily the results of valuations supplied by the investment advisors responsible for managing the assets of each plan, which we independently review for reasonableness. With respect to the Salaried VEBA, the investment advisors providing the valuations are engaged by the Salaried VEBA trustees.

Certain plan assets are valued based upon unadjusted quoted market prices in active markets that are accessible at the measurement date for identical, unrestricted assets (e.g., liquid securities listed on an exchange). Such assets are classified within Level 1 of the fair value hierarchy.

The following table presents the fair value of plan assets at December 31, 2024 and 2023, classified under the appropriate level of the fair value hierarchy (in millions of dollars):

 

 

 

December 31, 2024

 

 

December 31, 2023

 

 

Plan Assets in the Fair Value Hierarchy:

 

Level 1

 

 

Salaried VEBA – Equity investment funds in registered investment companies1

 

$

25.2

 

 

$

25.5

 

 

Salaried VEBA – Fixed income investment funds in registered investment companies2

 

 

16.8

 

 

 

16.5

 

 

Salaried VEBA – Cash and money market investments

 

 

0.2

 

 

 

—

 

 

Pension plans – Diversified investment funds in pooled separate accounts3

 

 

17.1

 

 

 

11.2

 

 

Pension plans – Diversified investment funds in registered investment companies4

 

 

5.4

 

 

 

9.3

 

 

Deferred compensation program – Diversified investment funds in registered investment companies4

 

 

11.9

 

 

 

11.1

 

 

Total plan assets in the fair value hierarchy

 

$

76.6

 

 

$

73.6

 

 

 

1.
Equity investment funds in registered investment companies. This category represents investments in equity funds.
2.
Fixed income investment funds in registered investment companies. This category represents investments in various fixed income funds with multiple registered investment companies. Such funds invest primarily in bonds, debentures, notes, securities with equity and fixed-income characteristics, cash equivalents, securities backed by mortgages and other assets, loans, pooled or collective investment vehicles made up of fixed‑income securities and other fixed-income obligations of banks, corporations, and governmental authorities.
3.
Diversified investment funds in pooled separate accounts. The plan assets are invested in various pooled separate accounts that hold a diversified portfolio of: (i) equity and equity-related securities of U.S. and non-U.S. issuers across all market capitalizations; (ii) fixed income securities such as corporate bonds and government bonds; and (iii) commercial real estate, including mortgage loans which are backed by the associated properties. The pooled separate accounts are valued daily based on the market value of the underlying net assets in each separate account. The majority of the underlying net assets have observable Level 1 pricing inputs which are used to determine the unit value of the pooled separate account which is not publicly quoted.
4.
Diversified investment funds in registered investment companies. The assets in the rabbi trust are invested in investment funds that hold a diversified portfolio of: (i) U.S. and international debt and equity securities; (ii) fixed income securities such as corporate bonds and government bonds; (iii) mortgage-related securities; and (iv) cash and cash equivalents.

The following table presents the total expense related to all benefit plans (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Defined contribution plans1

 

$

18.6

 

 

$

18.1

 

 

$

17.1

 

Deferred compensation plan2

 

 

1.3

 

 

 

1.2

 

 

 

(0.6

)

Multiemployer pension plans1,3

 

 

6.1

 

 

 

5.6

 

 

 

5.2

 

Net periodic postretirement and postemployment benefit cost relating to defined benefit plans2,3,4

 

 

9.0

 

 

 

13.4

 

 

 

13.1

 

Total

 

$

35.0

 

 

$

38.3

 

 

$

34.8

 

 

1.
Substantially all of these charges related to employee benefits are in COGS with the remaining balance in SG&A and R&D within our Statements of Consolidated Income (Loss).
2.
Deferred compensation plan expense and the current service cost component of Net periodic postretirement and postemployment benefit cost relating to Salaried VEBA are included within our Statements of Consolidated Income (Loss) in SG&A and R&D for all periods presented. All other components of Net periodic postretirement and postemployment benefit cost relating to Salaried VEBA are included within Other income, net, in our Statements of Consolidated Income (Loss).
3.
See Note 6 for more information on our multiemployer defined benefit pension plans. For the year ended December 31, 2024, the expense presented excludes a $4.6 million charge to Restructuring costs (see Note 12).
4.
The current service cost component of Net periodic postretirement and postemployment benefit cost relating to both the pension plans and the OPEB plan is included within COGS in our Statements of Consolidated Income (Loss) for all periods presented. All other components of Net periodic postretirement and postemployment benefit cost relating to both the pension plans and the OPEB plan are included within Other income, net, in our Statements of Consolidated Income (Loss).

Components of Net Periodic Postretirement and Postemployment Benefit Cost. The following table presents the components of Net periodic postretirement and postemployment benefit cost relating to our defined benefit plans (in millions of dollars):

 

 

 

Pension Plans

 

 

OPEB

 

 

Salaried VEBA

 

 

 

Year Ended December 31,

 

 

Year Ended December 31,

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

 

2024

 

 

2023

 

 

2022

 

 

2024

 

 

2023

 

 

2022

 

Service cost

 

$

3.6

 

 

$

3.8

 

 

$

5.8

 

 

$

1.1

 

 

$

1.1

 

 

$

1.6

 

 

$

—

 

 

 

—

 

 

$

0.1

 

Interest cost

 

 

1.6

 

 

 

1.3

 

 

 

0.6

 

 

 

3.3

 

 

 

3.4

 

 

 

2.2

 

 

 

2.2

 

 

 

2.9

 

 

 

1.9

 

Expected return on plan assets

 

 

(1.4

)

 

 

(1.1

)

 

 

(0.9

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(2.2

)

 

 

(2.2

)

 

 

(3.1

)

Amortization of prior service cost1

 

 

0.8

 

 

 

0.4

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

1.7

 

 

 

4.9

 

 

 

4.9

 

Amortization of net actuarial gain

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(1.1

)

 

 

(1.1

)

 

 

—

 

 

 

(0.1

)

 

 

—

 

 

 

—

 

Settlement gain recognized

 

 

(0.5

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Total net periodic postretirement and postemployment benefit cost

 

$

4.1

 

 

$

4.4

 

 

$

5.5

 

 

$

3.3

 

 

$

3.4

 

 

$

3.8

 

 

$

1.6

 

 

$

5.6

 

 

$

3.8

 

 

1.
We amortize prior service cost on a straight-line basis over the average remaining years of service of the active plan participants.
v3.25.0.1
Multiemployer Pension Plans
 12 Months Ended
Dec. 31, 2024
Retirement Benefits [Abstract]  
Multiemployer Pension Plans

6. Multiemployer Pension Plans

Overview. We contribute to multiemployer defined benefit pension plans under the terms of collective bargaining agreements that cover our union-represented employees at certain facilities. At December 31, 2024, approximately 34% of our total employees were union-represented employees at facilities participating in these multiemployer pension plans. We currently estimate that contributions will range from $5.5 million to $6.5 million in 2025.

The risks of participating in these multiemployer plans are different from single-employer plans in the following aspects:

•
Assets contributed to the multiemployer plan by one employer may be used to provide benefits to employees of other participating employers.
•
If a participating employer stops contributing to the plan, the unfunded obligations of the plan may be borne by the remaining participating employers.
•
If we choose to stop participating in any of our multiemployer plans, we may be required to pay those plans an amount based on the underfunded status of the plan, referred to as a withdrawal liability.

The following table presents information about multiemployer pension plans in which we participate:

 

 

 

 

 

Pension

 

FIP/RP Status

 

Contributions of

 

 

 

 

 

 

 

 

 

Employer

 

Protection Act

 

Pending/

 

the Company

 

 

Surcharge

 

Expiration Date

 

 

Identification

 

Zone Status1

 

Implemented

 

Year Ended December 31,

 

 

Imposed

 

of Collective-

Pension Fund

 

Number

 

2024

 

2023

 

in 2024²

 

2024

 

 

2023

 

 

2022

 

 

in 2024

 

Bargaining Agreements

 

 

 

 

 

 

 

 

 

 

(in millions of dollars)

 

 

 

 

 

 

 

USW3

 

23-6648508

 

Green

 

Green

 

No

 

$

4.7

 

 

$

4.2

 

 

$

3.8

 

 

No

 

Sep 2025 - Nov 2026

Other Funds4

 

 

 

 

 

 

 

 

 

 

1.4

 

 

 

1.4

 

 

 

1.4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

$

6.1

 

 

$

5.6

 

 

$

5.2

 

 

 

 

 

 

 

 

1.
The zone status is based on information that we received from the plan and is certified by the plan’s actuary. Among other factors, plans in the green zone are at least 80% funded.
2.
The “FIP/RP Status Pending/Implemented” column indicates if a Financial Improvement Plan (“FIP”) or a Rehabilitation Plan (“RP”) is either pending or has been implemented for the plan under the Pension Protection Act.
3.
We are party to three collective bargaining agreements with the USW that require contributions to the Steelworkers Pension Trust (“SPT”). As of December 31, 2024, USW collective bargaining agreements covering employees at Newark and Trentwood covered
87% of our USW-represented employees with SPT benefits and expire in September 2025. See Note 18 for information related to the renewal of the collective bargaining agreements. Our monthly contributions per hour worked by each bargaining unit employee at Newark and Trentwood were (in whole dollars) $1.75 in the first half of 2024 and $2.06 in the second half of 2024. The union contracts covering employees at our Richmond, Virginia facility and Florence, Alabama facility cover 10% and 3%, respectively, of our USW-represented employees with SPT benefits and expire in November 2026 and March 2026, respectively. Our monthly contributions per hour worked by each bargaining unit employee at our Richmond, Virginia facility and Florence, Alabama facility were (in whole dollars) $1.50 and $1.35, respectively, in 2024.
4.
Other Funds consists of plans that are not individually significant.

We were not listed in any of the plans’ Forms 5500 as providing more than 5% of the total contributions for any of the plan years disclosed. At the date the Company’s financial statements were issued, Forms 5500 were not available for the plan year ending in 2024. Further, there were no significant changes to the number of employees covered by our multiemployer plans that would affect the period-to-period comparability of the contributions for the years presented.
v3.25.0.1
Employee Incentive Plans
 12 Months Ended
Dec. 31, 2024
Share-Based Payment Arrangement [Abstract]  
Employee Incentive Plans

7. Employee Incentive Plans

Short-Term Incentive Plans (“STI Plans”)

We have annual short-term incentive compensation plans for senior management and certain other employees payable at our election in cash, shares of common stock, or a combination of cash and shares of common stock. Amounts earned under STI Plans are based on our Adjusted EBITDA, modified for certain safety, quality, delivery, cost, and individual performance factors. The Adjusted EBITDA targets are determined based on the return on adjusted net assets. Most of our production facilities have similar programs for both hourly and salaried employees. In addition, we have discretionary bonus programs that allow for management to incentivize employees based on performance. As of December 31, 2024, we had a liability of $13.3 million recorded within Accrued salaries, wages and related expenses for estimated probable future payments relating to the 12-month performance period of our 2024 STI Plans.

Long-Term Incentive Programs (“LTI Programs”)

General. Executive officers and other key employees of the Company, as well as non-employee directors of the Company, are eligible to participate in the Kaiser Aluminum Corporation 2021 Equity and Incentive Compensation Plan, as amended and restated (“2021 Plan”). The 2021 Plan was initially approved by stockholders on June 3, 2021, amended and restated on June 11, 2024 and replaced and succeeded, in its entirety, the Kaiser Aluminum Corporation Amended and Restated 2016 Equity and Performance Incentive Plan, except with regard to awards previously granted thereunder that continued to be outstanding. At December 31, 2024, 603,948 shares were available for awards under the 2021 Plan.

Non-Vested Common Shares and Restricted Stock Units. We grant non-vested common shares (“RSAs”) to our non-employee directors and restricted stock units (“RSUs”) to our executive officers and other key employees. The RSUs have rights similar to the rights of RSAs, and each RSU that becomes vested entitles the recipient to receive one common share, for which we issue new shares of our common stock upon vesting under the 2021 Plan. The service period is generally one year for RSAs granted to non-employee directors and three years for RSUs granted to executive officers and other key employees.

The following table summarizes activity relating to RSAs and RSUs for the year ended December 31, 2024:

 

 

 

Shares
(in whole shares)

 

 

Weighted-
Average
Grant-Date
Fair Value
per Share
(in whole dollars)

 

Outstanding at December 31, 2023

 

 

399,387

 

 

$

80.41

 

Granted

 

 

132,490

 

 

 

64.84

 

Vested

 

 

(107,831

)

 

 

97.57

 

Forfeited

 

 

(15,372

)

 

 

70.99

 

Outstanding at December 31, 2024

 

 

408,674

 

 

$

71.19

 

 

Performance Shares. We grant performance shares to executive officers and other key employees that vest upon the achievement of specified market or internal performance goals. Performance goals can include: (i) our achieving a total shareholder return (“TSR”) compared to the TSR of a specified group of peer companies over a three-year performance period (“TSR-Based Performance Shares”); (ii)

achieving targeted improvements to our total controllable cost performance over a three-year performance period; and/or (iii) achieving targeted improvements to our Adjusted EBITDA margin performance, measured by our Adjusted EBITDA as a percentage of Conversion Revenue, over a three-year performance period. Each performance share that becomes vested and earned entitles the recipient to receive one common share. The number of performance shares that may be earned and result in the issuance of common shares ranges between 0% to 200% of the target number of underlying performance shares.

The following table presents the weighted average inputs and assumptions used in the Monte Carlo simulations to calculate the fair value at the grant date of our TSR-Based Performance Shares:

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Grant date fair value (in whole dollars)

 

$

96.34

 

 

$

104.87

 

 

$

122.22

 

Grant date stock price (in whole dollars)

 

$

71.76

 

 

$

84.33

 

 

$

95.13

 

Expected volatility of Kaiser Aluminum1

 

 

45.59

%

 

 

49.72

%

 

 

49.37

%

Expected volatility of peer companies1

 

 

38.67

%

 

 

45.14

%

 

 

51.08

%

Risk-free interest rate

 

 

4.31

%

 

 

4.59

%

 

 

1.59

%

Dividend yield

 

 

4.29

%

 

 

3.65

%

 

 

3.24

%

 

1.
Weighted average expected volatility based on 2.8 years of daily closing share prices from the valuation date to the end of the performance period.

The following table summarizes activity relating to performance shares for the year ended December 31, 2024:

 

 

 

Shares
(in whole shares)

 

 

Weighted-
Average
Grant-Date
Fair Value
per Share
(in whole dollars)

 

Outstanding at December 31, 2023

 

 

328,616

 

 

$

114.79

 

Granted 1

 

 

175,662

 

 

 

86.50

 

Forfeited 1

 

 

(7,060

)

 

 

94.84

 

Canceled 1

 

 

(100,212

)

 

 

137.07

 

Outstanding at December 31, 2024

 

 

397,006

 

 

$

97.00

 

 

1.
The number of shares granted and forfeited are presented at their maximum payout; and the number of shares canceled includes the number of shares that did not vest due to performance results falling below those required for maximum payout.

Non-Cash Compensation Expense. Non-cash compensation expense is primarily included in SG&A and R&D. The following table presents non-cash compensation expense by type of award under LTI Programs (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

RSAs and RSUs

 

$

8.9

 

 

$

10.7

 

 

$

8.8

 

Performance shares

 

 

4.9

 

 

 

4.7

 

 

 

4.9

 

Total non-cash compensation expense

 

$

13.8

 

 

$

15.4

 

 

$

13.7

 

 

Recognized tax benefits relating to the non-cash compensation expense presented in the table above were $3.2 million, $3.6 million, and $3.2 million for 2024, 2023, and 2022, respectively.

The aggregate fair value of awards that vested was $8.5 million, $6.2 million, and $9.1 million for 2024, 2023, and 2022, respectively, which represents the market value of our common stock on the date that the awards vested.

Unrecognized Gross Compensation Cost Data. The following table presents unrecognized gross compensation costs and the expected period over which the remaining gross compensation costs will be recognized by type of award as of December 31, 2024:

 

 

 

Unrecognized Gross Compensation Costs
(in millions
of dollars)

 

 

Expected Period
(in years)
Over Which the Remaining Gross Compensation Costs Will Be Recognized

 

RSAs and RSUs

 

$

12.6

 

 

 

2.1

 

Performance shares

 

$

6.1

 

 

 

1.8

 

 

The following table presents the weighted-average grant-date fair value per share for shares granted by type of award (in whole dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

RSAs and RSUs

 

$

64.84

 

 

$

71.81

 

 

$

84.16

 

Performance shares

 

$

86.50

 

 

$

96.65

 

 

$

111.37

 

 

Participants may elect to have us withhold common shares to satisfy minimum statutory tax withholding obligations arising in connection with the vesting of RSAs, RSUs, and performance shares. We cancel any such shares withheld on the applicable vesting dates or earlier dates when service requirements are satisfied, which correspond to the times at which income to the participant is recognized. When we withhold these common shares, we are required to remit to the appropriate taxing authorities the fair value of the shares withheld as of the vesting date. The withholding of common shares by us could be deemed a purchase of the common shares. See Statements of Consolidated Stockholders’ Equity for details on cancellation of shares to cover tax withholdings upon common shares issued.
v3.25.0.1
Derivatives, Hedging Programs and Other Financial Instruments
 12 Months Ended
Dec. 31, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Derivatives, Hedging Programs and Other Financial Instruments

8. Derivatives, Hedging Programs and Other Financial Instruments

Overview. In conducting our business, we enter into derivative transactions, including forward contracts and options, to limit our exposure to: (i) metal price risk related to our sale of fabricated aluminum products and the purchase of metal, including primary, rolling ingot and scrap, or recycled, aluminum, our main raw material, and certain alloys used as raw material for our fabrication operations; (ii) energy price risk related to fluctuating prices of natural gas and electricity used in our production processes; and (iii) foreign currency exchange rate risk related to certain equipment and service agreements with vendors for which payments are due in foreign currency. We do not use derivative financial instruments for trading or other speculative purposes. Hedging transactions are executed centrally on behalf of all of our operations to minimize transaction costs, monitor consolidated net exposures, and allow for increased responsiveness to changes in market factors.

Our derivative activities are overseen by a committee (“Hedging Committee”), which is composed of our Chief Executive Officer, Chief Financial Officer, Chief Accounting Officer, Treasurer, Executive Vice President of Manufacturing and other officers and employees selected by the Chief Executive Officer. The Hedging Committee meets regularly to review commodity price exposure, derivative positions, and strategy. Management reviews the scope of the Hedging Committee’s activities with our Board of Directors.

We are exposed to counterparty credit risk on all of our derivative instruments, which we manage by monitoring the credit quality of our counterparties and allocating our hedging positions among multiple counterparties to limit exposure to any single entity. Our counterparties are major investment grade financial institutions or trading companies, and our hedging transactions are governed by negotiated International Swaps and Derivatives Association Master Agreements, which generally require collateral to be posted by our counterparties above specified credit thresholds which may adjust up or down, based on increases or decreases in counterparty credit ratings. As a result, we believe the risk of loss is remote and contained. The aggregate fair value of our derivative instruments that were in a net liability position was $0.8 million and $1.0 million at December 31, 2024 and December 31, 2023, respectively, and we had no collateral posted as of those dates.

In addition, our firm-price customer sales commitments create incremental customer credit risk related to metal price movements. Under certain circumstances, we mitigate this risk by periodically requiring cash collateral to be posted by our customers, which we classify as deferred revenue and include as a component of Other accrued liabilities. We had no material cash collateral posted by our customers at

both December 31, 2024 and December 31, 2023. For more information about concentration risks concerning customers and suppliers, see Note 17.

Cash Flow Hedges

We designate as cash flow hedges forward swap contracts for aluminum and energy. Additionally, in the fourth quarter of 2023, we adopted this treatment for our Alloying Metals. We also designate as cash flow hedges foreign currency forward contracts for equipment and services for which payments are due in foreign currency. Unrealized gains and losses associated with our cash flow hedges are deferred in Other comprehensive income, net of tax, and reclassified to COGS when such hedges settle or when it is probable that the original forecasted transactions will not occur by the end of the originally specified time period. See Note 11 for the total amount of gain or loss on derivative instruments designated and qualifying as cash flow hedging instruments that was reported in AOCI, as well as the related reclassifications into earnings and tax effects. Cumulative gains and losses related to cash flow hedges are reclassified out of AOCI and recorded within COGS when the associated hedged commodity purchases impact earnings.

Aluminum Hedges. Our pricing of fabricated aluminum products is generally intended to lock in our Conversion Revenue (representing our value added from the fabrication process) and to pass through aluminum price fluctuations to our customers. For some of our higher margin products sold on a spot basis, the pass through of aluminum price movements can sometimes lag by as much as several months, with a favorable impact to us when aluminum prices decline and an adverse impact to us when aluminum prices increase. Additionally, in certain instances, we enter into firm-price arrangements with our customers for stipulated volumes to be delivered in the future. Because we generally purchase primary and secondary aluminum on a floating price basis, the lag in passing through aluminum price movements to customers on some of our higher margin products sold on a spot basis and the volume that we have committed to sell to our customers under a firm-price arrangement create aluminum price risk for us. We use third-party hedging instruments to limit exposure to aluminum price risk related to the aluminum pass through lag on some of our products and firm-price customer sales contracts.

Alloying Metals Hedges. We are exposed to the risk of fluctuating prices for alloying metals used as raw materials in our fabrication operations. We, from time to time, in the ordinary course of business, enter into hedging transactions and/or physical delivery commitments with third parties to mitigate our risk from fluctuations in certain alloying metals prices that are not passed through pursuant to the terms of our customer contracts.

Energy Hedges. We are exposed to the risk of fluctuating prices for natural gas and electricity. We, from time to time, in the ordinary course of business, enter into hedging transactions and/or firm-price physical delivery commitments with third parties to mitigate our risk from fluctuations in natural gas and electricity prices that are not passed through pursuant to the terms of our customer contracts.

Foreign Currency Hedges. We are exposed to foreign currency exchange rate risk related to certain equipment and service agreements with vendors for which payments are due in foreign currency. We, from time to time, in the ordinary course of business, use foreign currency forward contracts in order to mitigate the exposure to currency exchange rate fluctuations related to these purchases.

Non-Designated Hedges of Operational Risks

From time to time, we enter into commodity and foreign currency forward contracts that are not designated as hedging instruments to mitigate certain short‑term impacts, as identified. The gain or loss on these commodity and foreign currency derivatives is recognized within COGS and Other income, net, respectively. As of December 31, 2024 and December 31, 2023, we had no outstanding non-designated derivative positions.

Notional Amount of Derivative Contracts

The following table summarizes our derivative positions at December 31, 2024:

 

Aluminum

 

Maturity Period

 

Notional Amount of Contracts (mmlbs)

 

Fixed price purchase contracts for LME

 

January 2025 through April 2026

 

 

57.8

 

Fixed price sale contracts for LME

 

January 2025

 

 

10.5

 

Fixed price purchase contracts for MWTP

 

January 2025 through April 2026

 

 

49.9

 

Fixed price sale contracts for MWTP

 

January 2025

 

 

10.5

 

 

 

Alloying Metals

 

Maturity Period

 

Notional Amount of Contracts (mmlbs)

 

Fixed price purchase contracts

 

January 2025 through December 2026

 

 

9.0

 

 

Natural Gas

 

Maturity Period

 

Notional Amount of Contracts (mmbtu)

 

Fixed price purchase contracts

 

January 2025 through December 2026

 

 

2,760,000

 

 

Euros

 

Maturity Period

 

Notional Amount of Contracts (EUR)

 

Fixed price forward purchase contracts

 

January 2025 through July 2027

 

 

7,236,092

 

 

British Pounds

 

Maturity Period

 

Notional Amount of Contracts (GBP)

 

Fixed price forward purchase contracts

 

January 2025 through February 2025

 

 

20,000

 

(Gain) Loss on Derivative Contracts

The following table summarizes the amount of (gain) loss on derivative contracts recorded within our Statements of Consolidated Income (Loss) in COGS (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

2024

 

 

2023

 

 

2022

 

Total of income and expense line items presented in our Statements of Consolidated Income (Loss) in which the effects of hedges are recorded:

 

 

 

 

 

Cash flow hedges

 

$

2,691.1

 

 

$

2,754.9

 

 

$

3,180.2

 

 

 

 

 

 

 

 

 

 

(Gain) loss recognized in our Statements of Consolidated Income (Loss) related to cash flow hedges:

 

 

 

 

 

 

 

 

 

Aluminum

 

$

(1.4

)

 

$

12.8

 

 

$

7.4

 

Alloying Metals

 

 

(1.1

)

 

 

—

 

 

 

—

 

Natural gas

 

 

1.0

 

 

 

0.1

 

 

 

(6.6

)

Electricity

 

 

0.6

 

 

 

—

 

 

 

(11.3

)

Total (gain) loss recognized in our Statements of Consolidated Income (Loss) related to cash flow hedges

 

$

(0.9

)

 

$

12.9

 

 

$

(10.5

)

 

 

 

 

 

 

 

 

 

Loss (gain) recognized in our Statements of Consolidated Income (Loss) related to non-designated hedges:

 

 

 

 

 

 

 

 

 

Alloying Metals – Realized loss (gain)

 

$

—

 

 

$

0.1

 

 

$

(0.5

)

Alloying Metals – Unrealized mark-to-market loss

 

 

—

 

 

 

—

 

 

 

1.4

 

Electricity – Realized loss

 

 

5.0

 

 

 

—

 

 

 

—

 

Total loss recognized in our Statements of Consolidated Income (Loss) related to non-designated hedges

 

$

5.0

 

 

$

0.1

 

 

$

0.9

 

 

Fair Values of Derivative Contracts

The fair values of our derivative contracts are based upon trades in liquid markets. Valuation model inputs can be verified, and valuation techniques do not involve significant judgment. The fair values of such financial instruments are classified within Level 2 of the fair value hierarchy.

All of our derivative contracts with counterparties are subject to enforceable master netting arrangements. We reflect the fair value of our derivative contracts on a gross basis on our Consolidated Balance Sheets. The following table presents the fair value of our derivative financial instruments (in millions of dollars):

 

 

 

As of December 31, 2024

 

 

As of December 31, 2023

 

 

 

Assets

 

 

Liabilities

 

 

Net Amount

 

 

Assets

 

 

Liabilities

 

 

Net Amount

 

Aluminum –

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fixed price purchase contracts for LME

 

$

1.1

 

 

$

(0.8

)

 

$

0.3

 

 

$

3.4

 

 

$

(0.6

)

 

$

2.8

 

Fixed price sale contracts for LME

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(0.2

)

 

 

(0.2

)

Fixed price purchase contracts for MWTP

 

 

1.1

 

 

 

—

 

 

 

1.1

 

 

 

0.4

 

 

 

(0.3

)

 

 

0.1

 

Fixed price sale contracts for MWTP

 

 

—

 

 

 

—

 

 

 

—

 

 

 

0.1

 

 

 

(0.2

)

 

 

(0.1

)

Alloying Metals – Fixed price purchase contracts

 

 

1.3

 

 

 

(0.1

)

 

 

1.2

 

 

 

0.7

 

 

 

(0.1

)

 

 

0.6

 

Natural gas – Fixed price purchase contracts

 

 

0.5

 

 

 

(0.8

)

 

 

(0.3

)

 

 

0.3

 

 

 

(0.9

)

 

 

(0.6

)

Electricity – Fixed price purchase contracts

 

 

—

 

 

 

—

 

 

 

—

 

 

 

0.5

 

 

 

(0.6

)

 

 

(0.1

)

Foreign Currency – Fixed price forward contracts

 

 

—

 

 

 

(0.4

)

 

 

(0.4

)

 

 

0.5

 

 

 

—

 

 

 

0.5

 

Total

 

$

4.0

 

 

$

(2.1

)

 

$

1.9

 

 

$

5.9

 

 

$

(2.9

)

 

$

3.0

 

 

The following table presents the total amounts of derivative assets and liabilities on our Consolidated Balance Sheets (in millions of dollars):

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

Derivative assets:

 

 

 

 

 

 

Prepaid expenses and other current assets

 

$

3.7

 

 

$

4.8

 

Other assets

 

 

0.3

 

 

 

1.1

 

Total derivative assets

 

$

4.0

 

 

$

5.9

 

Derivative liabilities:

 

 

 

 

 

 

Other accrued liabilities

 

$

(1.8

)

 

$

(2.4

)

Long-term liabilities

 

 

(0.3

)

 

 

(0.5

)

Total derivative liabilities

 

$

(2.1

)

 

$

(2.9

)

 

Fair Value of Other Financial Instruments

All Other Financial Assets and Liabilities. We believe that the fair values of our accounts receivable, contract assets, accounts payable, and accrued liabilities approximate their respective carrying values due to their short maturities and nominal credit risk.
v3.25.0.1
Debt and Credit Facility
 12 Months Ended
Dec. 31, 2024
Debt Disclosure [Abstract]  
Debt and Credit Facility

9. Debt and Credit Facility

Senior Notes

At December 31, 2024 and 2023, we had outstanding fixed-rate unsecured Senior Notes with varying maturity dates. The stated interest rates and aggregate principal amounts of such Senior Notes were, respectively: (i) 4.625% and $500.0 million (“4.625% Senior Notes”) and (ii) 4.50% and $550.0 million (“4.50% Senior Notes”). Our Senior Notes do not require us to make any mandatory redemptions or sinking fund payments. The following table summarizes key details of our outstanding Senior Notes:

 

 

 

 

 

 

 

 

Outstanding (in millions of dollars)

 

 

 

Issuance Date

 

Maturity

 

Effective Interest Rate

 

As of December 31, 2024

 

 

As of December 31, 2023

 

4.625% Senior Notes

 

November 2019

 

March 2028

 

4.8%

 

$

500.0

 

 

$

500.0

 

4.50% Senior Notes

 

May 2021

 

June 2031

 

4.7%

 

 

550.0

 

 

 

550.0

 

Total debt

 

 

 

 

 

 

 

 

1,050.0

 

 

 

1,050.0

 

Unamortized issuance costs

 

 

 

 

 

 

 

 

(8.4

)

 

 

(10.2

)

Total carrying amount

 

 

 

 

 

 

 

$

1,041.6

 

 

$

1,039.8

 

 

The following table presents the fair value of our outstanding Senior Notes, which are Level 1 liabilities (in millions of dollars):

 

 

 

 

 

 

 

As of December 31,

 

 

 

 

 

 

 

2024

 

 

2023

 

4.625% Senior Notes

 

 

 

 

 

$

470.1

 

 

$

462.4

 

4.50% Senior Notes

 

 

 

 

 

$

484.8

 

 

$

474.1

 

Revolving Credit Facility

In October 2019, we entered into a Revolving Credit Facility. Joining us as borrowers under the Revolving Credit Facility are four of our wholly owned domestic operating subsidiaries: (i) Kaiser Aluminum Investments Company; (ii) Kaiser Aluminum Fabricated Products, LLC; (iii) Kaiser Aluminum Washington, LLC; and (iv) Kaiser Aluminum Warrick, LLC.

As amended, the Revolving Credit Facility contains a maximum commitment amount of $575.0 million (of which up to a maximum of $50.0 million may be utilized for letters of credit) and is set to mature in April 2027. The amount we can borrow under our Revolving Credit Facility is determined by the value of our receivables and inventory, which serve as collateral for the facility. Our effective interest rate on outstanding borrowings under the amended Revolving Credit Facility is based on the rates of Base Rate Loans and SOFR Loans (as defined in the amended Revolving Credit Facility). The rate for Base Rate Loans is equal to the prevailing Prime Rate plus 0.25% (or if borrowing availability is less than 40% of the maximum revolving commitments, 0.50%), while the rate for SOFR Loans, which are made for one or three month periods, is equal to the Term SOFR Reference Rate (as defined in the amended Revolving Credit Facility) plus 1.35% (or, if borrowing availability is less than 40% of the maximum revolving commitments, 1.50%). Outstanding borrowings under the Revolving Credit Facility are reported within Long-term debt, net, on our Consolidated Balance Sheets. We had no outstanding borrowings under our Revolving Credit Facility as of or during the year ended December 31, 2024. We also had no outstanding borrowings under our Revolving Credit Facility as of December 31, 2023, after repaying borrowings of $215.1 million incurred during the year ended December 31, 2023.

The following table summarizes availability and usage of our Revolving Credit Facility as determined by a borrowing base calculated as of December 31, 2024 (in millions of dollars):

 

Revolving Credit Facility borrowing commitment

 

$

575.0

 

Borrowing base availability

 

$

575.0

 

Less: Outstanding borrowings under Revolving Credit Facility

 

 

—

 

Less: Outstanding letters of credit under Revolving Credit Facility

 

 

(21.6

)

Remaining borrowing availability

 

$

553.4

 

 

Interest Expense and Future Maturities

The following table presents interest expense relating to our Senior Notes and Revolving Credit Facility (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Senior Notes interest expense, including debt issuance cost amortization

 

$

49.6

 

 

$

49.6

 

 

$

49.6

 

Revolving Credit Facility interest expense, including commitment fees and finance cost amortization

 

 

2.4

 

 

 

3.0

 

 

 

2.0

 

Interest expense on finance lease liabilities

 

 

0.8

 

 

 

0.7

 

 

 

0.3

 

Interest expense capitalized as construction in progress

 

 

(9.1

)

 

 

(6.4

)

 

 

(3.6

)

Total interest expense

 

$

43.7

 

 

$

46.9

 

 

$

48.3

 

 

The following table presents the future principal payments for our Senior Notes and Revolving Credit Facility as of December 31, 2024 (in millions of dollars):

 

Year ending December 31,

 

 

2025

$

—

 

2026

 

—

 

2027

 

—

 

2028

 

500.0

 

2029

 

—

 

Thereafter

 

550.0

 

Total

$

1,050.0

 
v3.25.0.1
Commitments and Contingencies
 12 Months Ended
Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies

10. Commitments and Contingencies

Commitments. We have a variety of financial commitments, including purchase agreements, forward foreign exchange and forward sales contracts, indebtedness, and letters of credit (see Note 3, Note 8, and Note 9).

CAROs. The inputs in estimating the fair value of CAROs include: (i) the timing of when any such CARO cash flows may be incurred; (ii) incremental costs associated with special handling or treatment of CARO materials; and (iii) the credit-adjusted risk-free rate applicable at the time additional CARO cash flows are estimated. The majority of these inputs are considered Level 3 inputs as they involve significant judgment from us.

The following table summarizes activity relating to CARO liabilities (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Beginning balance

 

$

10.9

 

 

$

10.1

 

 

$

7.2

 

Liabilities added during the period

 

 

—

 

 

 

—

 

 

 

2.3

 

Liabilities settled during the period

 

 

(0.1

)

 

 

—

 

 

 

(0.1

)

Accretion expense

 

 

0.9

 

 

 

0.8

 

 

 

0.7

 

Ending balance

 

$

11.7

 

 

$

10.9

 

 

$

10.1

 

The estimated fair values of CARO liabilities were based upon the application of a weighted-average credit-adjusted risk-free rate of 8.30% and 8.26% at December 31, 2024 and December 31, 2023, respectively. CAROs are included in Other accrued liabilities or Long-term liabilities, as appropriate.

Environmental Contingencies. We are subject to a number of environmental laws and regulations, potential fines or penalties assessed for alleged breaches of such laws and regulations, and potential claims based upon such laws and regulations. We are also subject to legacy environmental contingencies related to activities that occurred at operating facilities prior to July 6, 2006, which represent the majority of our environmental accruals. The status of these environmental contingencies are discussed below. We have established procedures for regularly evaluating environmental loss contingencies. Our environmental accruals represent our undiscounted estimate of costs reasonably

expected to be incurred based on presently enacted laws and regulations, currently available facts, existing requirements, existing technology and our assessment of the likely remediation actions to be taken.

We continue to pursue remediation activities, primarily to address the historical use of oils containing polychlorinated biphenyls (“PCBs”) at Trentwood. Our remediation efforts are in collaboration with the Washington State Department of Ecology (“Ecology”), to which we submitted a feasibility study in 2012 of remediation alternatives and from which we received permission to begin certain remediation activities pursuant to a signed work order. We have completed a number of sections of the work plan and have received satisfactory completion approval from Ecology on those sections. In cooperation with Ecology, we constructed an experimental treatment facility to determine the treatability and evaluate the feasibility of removing PCBs from ground water under Trentwood. In 2015, we began treatment operations involving a walnut shell filtration system, which we optimized for maximum PCB capture during 2020. Furthermore, based on advancements in technology, we signed an Amended Agreed Order with Ecology to evaluate and implement a new Ultraviolet Light Advanced Oxidation Process (“UV/AOP”) for PCB removal from groundwater on a pilot basis. During 2024, based on the positive results of the UV/AOP, we implemented a full-scale UV/AOP treatment system that is operational as of December 31, 2024. We are currently working with Ecology, as required by the Amended Agreed Order, to finalize details of the UV/AOP and also determine future remediation steps to be taken at which time there may be revisions to our estimated liabilities for this matter.

Pursuant to a consent agreement with the Ohio Environmental Protection Agency (“OEPA”), we initiated an investigational study of Newark related to historical on-site waste disposal. During the quarter ended December 31, 2018, we submitted our remedial investigation study to the OEPA for review and approval. The final remedial investigation report was approved by the OEPA during the quarter ended December 31, 2020. During the quarter ended December 31, 2023, we submitted an Alternate Arrays Document (“AAD”) to the OEPA for review. During the quarter ended September 30, 2024, based on input from the OEPA and the proposed remediation options included in the AAD, we increased our accrual by $2.9 million. This increase reflects updated preliminary estimates for the most likely remediation activities, as laid out in the AAD. Once the AAD is reviewed and accepted by the OEPA, we plan to submit our feasibility study to the OEPA, which we expect to occur in 2025.

The following table presents the changes in our environmental accrual. We classify the short-term and long-term liabilities within Other accrued liabilities and Long-term liabilities, respectively, on our Consolidated Balance Sheets (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Beginning balance

 

$

17.0

 

 

$

17.7

 

 

$

16.8

 

Additional accruals

 

 

4.2

 

 

 

1.2

 

 

 

3.2

 

Less: expenditures

 

 

(2.8

)

 

 

(1.9

)

 

 

(2.3

)

Ending balance

 

$

18.4

 

 

$

17.0

 

 

$

17.7

 

 

At December 31, 2024, our environmental accrual of $18.4 million represented our estimate of the incremental remediation cost based on: (i) proposed alternatives in the final feasibility study related to Trentwood; (ii) currently available facts with respect to Newark; and (iii) facts related to certain other locations owned or formerly owned by us. In accordance with approved and proposed remediation action plans, we expect that the implementation and ongoing monitoring could occur over a period of 30 or more years.

As additional facts are developed, feasibility studies are completed, remediation plans are modified, necessary regulatory approvals for the implementation of remediation are obtained, alternative technologies are developed, and/or other factors change, there may be revisions to management’s estimates and actual costs may exceed the current environmental accruals. We believe at this time that it is reasonably possible that undiscounted costs associated with these environmental matters may exceed current accruals by amounts that could be, in the aggregate, up to an estimated $13.4 million over the remediation period. It is reasonably possible that our recorded estimate will change in the next 12 months.

Other Contingencies. We are party to various lawsuits, claims, investigations and administrative proceedings that arise in connection with past and current operations. We evaluate such matters on a case-by-case basis and our policy is to vigorously contest any such claims we believe are without merit. We accrue for a legal liability when it is both probable that a liability has been incurred and the amount of the loss is reasonably estimable. Quarterly, in addition to when changes in facts and circumstances require it, we review and adjust these accruals to reflect the impacts of negotiations, settlements, rulings, advice of legal counsel, and other information and events pertaining to a particular case. While uncertainties are inherent in the final outcome of such matters and it is presently impossible to determine the actual cost that may ultimately be incurred, we believe that we have sufficiently accrued for such matters and that the ultimate resolution of pending matters will not have a material impact on our consolidated financial position, operating results or liquidity.
v3.25.0.1
Accumulated Other Comprehensive Income
 12 Months Ended
Dec. 31, 2024
Equity [Abstract]  
Accumulated Other Comprehensive Income

11. Accumulated Other Comprehensive Income

The following table presents the changes in the accumulated balances for each component of AOCI (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Defined Benefit Plans:

 

 

 

 

 

 

 

 

 

Beginning balance

 

$

11.0

 

 

$

2.8

 

 

$

(21.4

)

Actuarial gain arising during the period

 

 

12.2

 

 

 

4.3

 

 

 

27.0

 

Less: income tax expense

 

 

(2.8

)

 

 

(1.0

)

 

 

(6.5

)

Net actuarial gain arising during the period

 

 

9.4

 

 

 

3.3

 

 

 

20.5

 

Prior service (cost) credit arising during the period

 

 

(2.2

)

 

 

2.2

 

 

 

—

 

Less: income tax benefit (expense)

 

 

0.5

 

 

 

(0.5

)

 

 

—

 

Net prior service (cost) credit arising during the period

 

 

(1.7

)

 

 

1.7

 

 

 

—

 

Amortization of net actuarial gain1,2

 

 

(2.0

)

 

 

(1.1

)

 

 

—

 

Amortization of prior service cost1

 

 

2.5

 

 

 

5.3

 

 

 

4.9

 

Less: income tax expense3

 

 

(0.1

)

 

 

(1.0

)

 

 

(1.2

)

Net amortization reclassified from AOCI to Net income (loss)

 

 

0.4

 

 

 

3.2

 

 

 

3.7

 

Other comprehensive income, net of tax

 

 

8.1

 

 

 

8.2

 

 

 

24.2

 

Ending balance

 

$

19.1

 

 

$

11.0

 

 

$

2.8

 

 

 

 

 

 

 

 

 

 

Cash Flow Hedges:

 

 

 

 

 

 

 

 

 

Beginning balance

 

$

2.1

 

 

$

0.4

 

 

$

17.7

 

Unrealized loss on cash flow hedges

 

 

(0.2

)

 

 

(10.7

)

 

 

(12.2

)

Less: income tax benefit

 

 

—

 

 

 

2.5

 

 

 

2.9

 

Net unrealized loss on cash flow hedges

 

 

(0.2

)

 

 

(8.2

)

 

 

(9.3

)

Reclassification of unrealized (gain) loss upon settlement
   of cash flow hedges

 

 

(0.9

)

 

 

12.9

 

 

 

(10.5

)

Reclassification due to forecasted transactions probable of not
   occurring

 

 

0.2

 

 

 

—

 

 

 

—

 

Less: income tax benefit (expense)3

 

 

0.2

 

 

 

(3.0

)

 

 

2.5

 

Net (gain) loss reclassified from AOCI to Net income (loss)

 

 

(0.5

)

 

 

9.9

 

 

 

(8.0

)

Other comprehensive (loss) income, net of tax

 

 

(0.7

)

 

 

1.7

 

 

 

(17.3

)

Ending balance4

 

$

1.4

 

 

$

2.1

 

 

$

0.4

 

 

 

 

 

 

 

 

 

 

Total AOCI ending balance

 

$

20.5

 

 

$

13.1

 

 

$

3.2

 

 

1.
Amounts amortized out of AOCI related to pension and other postretirement and postemployment benefits were included within Net periodic postretirement and postemployment benefit cost (see Note 5).
2.
Amounts amortized out of AOCI during the year ended December 31, 2024 include net actuarial gains recognized on a pro-rata basis in conjunction with a group annuity purchase (see Note 5).
3.
Income tax amounts reclassified out of AOCI were included as a component of Income tax (provision) benefit.
4.
As of December 31, 2024, we estimate a net mark-to-market gain before tax of $1.9 million in AOCI will be reclassified into Net income (loss) upon settlement within the next 12 months.
v3.25.0.1
Restructuring
 12 Months Ended
Dec. 31, 2024
Restructuring and Related Activities [Abstract]  
Restructuring

12. Restructuring

2024 Restructuring Plan. During the quarter ended June 30, 2024, we initiated a plan to exit our soft alloy aluminum extrusion facility located in Sherman, Texas (“2024 Restructuring Plan”). Through December 31, 2024, we have recorded a charge of $7.5 million, consisting of a $4.6 million multiemployer pension obligation which is expected to be paid in 2027 and a $2.9 million charge for severance, related benefits, and other costs. Substantially all of the costs associated with the restructuring efforts initiated under the 2024 Restructuring Plan were incurred and expensed as of December 31, 2024. The costs are recorded within Restructuring costs in our Statements of Consolidated Income.

The following table summarizes activity relating to the 2024 Restructuring Plan liabilities (in millions of dollars):

BALANCE, December 31, 2023

 

$

—

 

Restructuring costs

 

 

7.5

 

Costs paid or otherwise settled1

 

 

(2.8

)

BALANCE, December 31, 2024

 

$

4.7

 
1.
Cash paid during the year ended December 31, 2024 was $2.6 million.

2022 Restructuring Plan. During 2022, we relocated our corporate headquarters from Foothill Ranch, California (“Foothill Ranch”) to Franklin, Tennessee (“Franklin”). In conjunction with the relocation, we initiated a restructuring plan during the quarter ended December 31, 2022, which consisted primarily of employee retention benefits aimed at incentivizing Foothill Ranch employees to assist with the buildout of the new corporate function in Franklin (“2022 Restructuring Plan”). We incurred total restructuring costs of $7.3 million related to the 2022 Restructuring Plan, which consisted of employee-related costs and office rent within Restructuring costs in our Statements of Consolidated Income. We completed the 2022 Restructuring Plan as of June 30, 2024.

The following table summarizes activity relating to the 2022 Restructuring Plan liabilities (in millions of dollars):

BALANCE, December 31, 2021

 

$

—

 

Restructuring costs

 

 

2.2

 

Costs paid or otherwise settled1

 

 

(0.5

)

BALANCE, December 31, 2022

 

 

1.7

 

Restructuring costs

 

 

5.0

 

Costs paid or otherwise settled1

 

 

(5.5

)

BALANCE, December 31, 2023

 

 

1.2

 

Restructuring costs

 

 

0.1

 

Costs paid or otherwise settled1

 

 

(1.3

)

BALANCE, December 31, 2024

 

$

—

 

 

1.
Cash paid during the years ended December 31, 2024, December 31, 2023, and December 31, 2022 was $1.2 million, $5.0 million, and $0.4 million respectively.
v3.25.0.1
Other Income, Net
 12 Months Ended
Dec. 31, 2024
Other Income and Expenses [Abstract]  
Other Income, Net

13. Other Income, Net

The following table presents the components of Other income, net, (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Interest income

 

$

3.6

 

 

$

1.7

 

 

$

1.3

 

Net periodic postretirement and postemployment benefit cost

 

 

(4.3

)

 

 

(8.4

)

 

 

(5.6

)

Unrealized gain (loss) on equity securities

 

 

0.3

 

 

 

0.6

 

 

 

(1.2

)

Gain on disposition of property, plant and equipment

 

 

3.8

 

 

 

13.8

 

 

 

6.0

 

Gain on business interruption insurance recoveries1

 

 

16.3

 

 

 

—

 

 

 

—

 

Post-acquisition funding received from Alcoa Corporation2

 

 

—

 

 

 

—

 

 

 

6.0

 

All other, net

 

 

(0.2

)

 

 

(0.3

)

 

 

(0.1

)

Other income, net

 

$

19.5

 

 

$

7.4

 

 

$

6.4

 

 

1.
Represents advances against business interruption insurance claims. We recognize such advances in the period in which the insurance proceeds are received or become realizable. As of December 31, 2024 we received net cash proceeds of $15.9 million.
2.
Represents reimbursement received for repairs and maintenance expenditures on certain machinery and equipment that we had purchased from Alcoa in connection with our March 31, 2021 acquisition of Warrick.

Supply Chain Financing. During the years ended December 31, 2024 and December 31, 2023, we sold trade accounts receivable totaling $1,078.6 million and $1,240.6 million, respectively, related to these supply chain financing arrangements, of which the financial institutions of our customers applied discount fees totaling $24.8 million and $29.7 million, respectively. To the extent discount fees related to the sale of trade accounts receivable under supply chain financing arrangements are not reimbursed by our customers, they are included

in Other income, net. As of December 31, 2024, we had been and/or expected to be substantially reimbursed by our customers for these discount fees, in accordance with the underlying sales agreements.
v3.25.0.1
Income Tax Matters
 12 Months Ended
Dec. 31, 2024
Income Tax Disclosure [Abstract]  
Income Tax Matters

14. Income Tax Matters

The following table presents Income (loss) before income taxes by geographic area (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Domestic

 

$

53.5

 

 

$

48.0

 

 

$

(44.6

)

Foreign

 

 

10.0

 

 

 

8.3

 

 

 

6.7

 

Income (loss) before income taxes

 

$

63.5

 

 

$

56.3

 

 

$

(37.9

)

 

Tax (Provision) Benefit. Income taxes are classified as either domestic or foreign based on whether payment is made or due to the United States or a foreign country. Certain income classified as foreign is also subject to domestic income taxes.

The following table presents the components of Income tax (provision) benefit (in millions of dollars):

 

 

 

Federal

 

 

Foreign

 

 

State

 

 

Total

 

Year Ended December 31, 2024

 

 

 

 

 

 

 

 

 

 

 

 

Current

 

$

(3.5

)

 

$

(3.1

)

 

$

(3.3

)

 

$

(9.9

)

Deferred

 

 

(10.9

)

 

 

0.6

 

 

 

1.3

 

 

$

(9.0

)

Benefit applied to decrease AOCI

 

 

1.9

 

 

 

—

 

 

 

0.3

 

 

$

2.2

 

Income tax (provision) benefit

 

$

(12.5

)

 

$

(2.5

)

 

$

(1.7

)

 

$

(16.7

)

Year Ended December 31, 2023

 

 

 

 

 

 

 

 

 

 

 

 

Current

 

$

—

 

 

$

(2.2

)

 

$

0.6

 

 

$

(1.6

)

Deferred

 

 

(11.6

)

 

 

0.1

 

 

 

1.0

 

 

 

(10.5

)

Benefit applied to decrease AOCI

 

 

2.5

 

 

 

0.1

 

 

 

0.4

 

 

 

3.0

 

Income tax (provision) benefit

 

$

(9.1

)

 

$

(2.0

)

 

$

2.0

 

 

$

(9.1

)

Year Ended December 31, 2022

 

 

 

 

 

 

 

 

 

 

 

 

Current

 

$

—

 

 

$

(1.1

)

 

$

(2.5

)

 

$

(3.6

)

Deferred

 

 

8.9

 

 

 

(0.8

)

 

 

1.6

 

 

 

9.7

 

Benefit applied to decrease AOCI

 

 

1.7

 

 

 

0.2

 

 

 

0.3

 

 

 

2.2

 

Income tax benefit (provision)

 

$

10.6

 

 

$

(1.7

)

 

$

(0.6

)

 

$

8.3

 

 

The following table presents a reconciliation between the (provision) benefit for income taxes and the amount computed by applying the federal statutory income tax rate to Income (loss) before income taxes (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Amount of federal income tax (provision) benefit based on the statutory rate

 

$

(13.3

)

 

$

(11.8

)

 

$

8.0

 

Decrease in federal valuation allowances

 

 

—

 

 

 

—

 

 

 

1.1

 

Non-deductible compensation expense

 

 

(2.2

)

 

 

(1.6

)

 

 

(0.9

)

Non-deductible (expense) benefit

 

 

(0.2

)

 

 

0.2

 

 

 

(1.0

)

State income tax (provision) benefit, net of federal benefit1

 

 

(1.4

)

 

 

1.5

 

 

 

(0.5

)

Research and development credit

 

 

1.2

 

 

 

3.2

 

 

 

2.2

 

Foreign income tax expense

 

 

(0.4

)

 

 

(0.3

)

 

 

(0.3

)

Foreign undistributed earnings

 

 

(0.4

)

 

 

(0.3

)

 

 

(0.3

)

Income tax (provision) benefit

 

$

(16.7

)

 

$

(9.1

)

 

$

8.3

 

 

1.
The total state income tax (provision) benefit, net of federal benefit was ($1.4) million in 2024, which was primarily a result of: (i) a current state income tax provision of ($1.5) million in 2024; (ii) a benefit of $2.9 million due to state NOL, return to provision and tax rate true-ups in various states, partially offset by (iii) an increase to the provision for a state tax valuation allowance of ($2.8) million related to the expiration of certain state net operating losses and credits. The total state income tax (provision) benefit, net of federal benefit was $1.5 million in 2023, which was primarily a result of: (i) a current state income tax provision of ($1.4) million in
2023; (ii) a benefit of $1.9 million due to state NOL and tax rate true-ups in various states; and (iii) a benefit of $1.0 million for a decrease to the state tax valuation allowance related to certain state net operating losses. The total state income tax (provision) benefit, net of federal benefit was ($0.5) million in 2022, which was primarily a result of: (i) a current state income tax benefit of $1.1 million in 2022; (ii) an increase of ($1.5) million to the provision due to state NOL and tax rate true-ups in various states; and (iii) an increase to the provision of ($0.1) million for an increase to the state tax valuation allowance related to the expiration of certain state net operating losses.

Deferred Income Taxes. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and amounts used for income tax purposes. The following table presents the components of our net deferred income tax assets and liabilities (in millions of dollars):

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

Deferred income tax assets:

 

 

 

 

 

 

Loss and credit carryforwards

 

$

17.3

 

 

$

39.6

 

Defined benefit plans

 

 

3.1

 

 

 

3.6

 

Other assets

 

 

35.8

 

 

 

36.8

 

Lease assets

 

 

7.2

 

 

 

8.7

 

Inventories

 

 

39.8

 

 

 

29.5

 

Excess interest carryforward

 

 

10.2

 

 

 

14.0

 

Research & development capitalization

 

 

19.1

 

 

 

16.9

 

Valuation allowances

 

 

(5.5

)

 

 

(2.7

)

Total deferred income tax assets

 

 

127.0

 

 

 

146.4

 

Deferred income tax liabilities:

 

 

 

 

 

 

Property, plant and equipment

 

 

(133.3

)

 

 

(142.6

)

Lease liabilities

 

 

(7.2

)

 

 

(8.7

)

Undistributed foreign earnings

 

 

(3.4

)

 

 

(3.0

)

Total deferred income tax liabilities

 

 

(143.9

)

 

 

(154.3

)

Net deferred income tax liabilities

 

$

(16.9

)

 

$

(7.9

)

 

Tax Attributes. At December 31, 2024, we had $12.6 million of federal research and development (“R&D”) credit carryforwards to offset regular federal income tax requirements. Our R&D credit carryforwards expire periodically through 2044. We also had $3.9 million of state credit carryforwards that will expire periodically through 2049.

In assessing the realizability of deferred tax assets, management considers whether it is “more likely than not” that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management considers taxable income in carryback years, the scheduled reversal of deferred tax liabilities, tax planning strategies, and projected future taxable income in making this assessment. Due to uncertainties surrounding the realization of some of our deferred tax assets, primarily including state NOL carryforwards sustained during the prior years and expiring tax benefits, we have a valuation allowance against certain deferred tax assets. When recognized, the tax benefits relating to any reversal of this valuation allowance will be recorded as a reduction of income tax expense. There was an increase in the valuation allowance of $2.8 million in 2024 and a decrease in the valuation allowance of $1.0 million in 2023.

The increase in the valuation allowance for 2024 was primarily due to unutilized state NOL and credit carryforwards. The decrease in the valuation allowance for 2023 was primarily due to the expiration of state NOL carryforwards and the related reversal of their valuation allowances.

Other. We and our subsidiaries file income tax returns in the U.S. federal jurisdiction and various states and foreign jurisdictions. The Company has various state income tax examinations that are currently in progress. Generally, with few exceptions, the Company’s 2020 and later tax years remain open for examination by the various state taxing authorities.

 

We have evaluated the effects of the Global anti-Base Erosion rules set forth by the Organization for Economic Co-Operation and Development, referred to as “Pillar 2,” which establishes a global minimum corporate tax rate of 15 percent. We have (i) determined that Pillar 2 legislation has been enacted in one or more of the jurisdictions in which the Company operates and the Company is within the scope of such legislation, (ii) assessed such enacted legislation and, as applicable, the Transitional Safe Harbor provisions for Pillar 2 that apply,

and (iii) determined the impact will be immaterial to our financial results. We intend to file a Qualified Country-by-Country Report for the current year for each jurisdiction in which we intend to rely on the Transitional Country-by-Country Reporting Safe Harbor provisions.

We have gross unrecognized benefits relating to uncertain tax positions. The following table presents a reconciliation of changes in the gross unrecognized tax benefits (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Gross unrecognized tax benefits at beginning of period

 

$

6.5

 

 

$

5.0

 

 

$

4.1

 

Gross increases for tax positions of current year

 

 

0.5

 

 

 

1.3

 

 

 

0.9

 

Gross increases for tax positions of prior years

 

 

—

 

 

 

0.2

 

 

 

0.1

 

Gross decreases for tax positions of prior years

 

 

(0.1

)

 

 

—

 

 

 

(0.1

)

Gross unrecognized tax benefits at end of period

 

$

6.9

 

 

$

6.5

 

 

$

5.0

 

 

If and when the $6.9 million of gross unrecognized tax benefits at December 31, 2024 are recognized, $6.9 million will be reflected in our income tax provision and thus affect the effective tax rate in future periods.

In addition, we recognize interest and penalties related to unrecognized tax benefits in the income tax provision. We had $0.1 million and $0.2 million accrued for interest and penalties at December 31, 2024 and December 31, 2023, respectively, and we recognized interest and penalties of $0.1 million in our tax provision in 2022. Of the amounts accrued, none were considered current and, as such, were included in Long-term liabilities on our Consolidated Balance Sheets as of December 31, 2024 and December 31, 2023.

We do not expect our gross unrecognized tax benefits to significantly change within the next 12 months.
v3.25.0.1
Net Income (Loss) Per Share
 12 Months Ended
Dec. 31, 2024
Earnings Per Share [Abstract]  
Net Income (Loss) Per Share

15. Net Income (Loss) Per Share

Basic net income (loss) per share is computed by dividing distributed and undistributed net income (loss) allocable to common shares by the weighted-average number of common shares outstanding during the applicable period. The basic weighted-average number of common shares outstanding during the period excludes non-vested share-based payment awards. Basic and diluted net income (loss) per share was calculated under the two-class method for 2024 and 2023, and the treasury method in 2022, based on the more dilutive method for each period.

The following table sets forth the computation of basic and diluted net income (loss) per share (in millions of dollars, except share and per share amounts):

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Numerator:

 

 

 

 

 

 

 

 

 

Net income (loss)

 

 

46.8

 

 

 

47.2

 

 

 

(29.6

)

Less: earnings attributable to participating securities1

 

 

—

 

 

 

(0.1

)

 

 

—

 

Net income (loss) available to common shareholders

 

 

46.8

 

 

 

47.1

 

 

 

(29.6

)

Denominator – Weighted-average common shares
   outstanding (in thousands):

 

 

 

 

 

 

 

 

 

Basic

 

 

16,069

 

 

 

15,991

 

 

 

15,906

 

Add: dilutive effect of non-vested common shares,
   restricted stock units and performance shares2

 

 

250

 

 

 

140

 

 

 

—

 

Diluted

 

 

16,319

 

 

 

16,131

 

 

 

15,906

 

 

 

 

 

 

 

 

 

 

Net income (loss) per common share, Basic

 

$

2.91

 

 

$

2.95

 

 

$

(1.86

)

Net income (loss) per common share, Diluted

 

$

2.87

 

 

$

2.92

 

 

$

(1.86

)
1.
Represents distributed and undistributed earnings allocated to non-vested RSAs that contain non-forfeitable rights to dividends.
2.
Quantities in the following discussion are denoted in whole shares. For the years ended December 31, 2024 and December 31, 2023, approximately 1,100 and 35,000 shares, respectively, were excluded from the weighted-average diluted shares computation as their inclusion would have been anti-dilutive. For the year ended December 31, 2022, approximately 139,000 potentially dilutive shares were excluded from the computation of net loss per share as their effect would have been anti‑dilutive.
v3.25.0.1
Supplemental Cash Flow Information
 12 Months Ended
Dec. 31, 2024
Supplemental Cash Flow Elements [Abstract]  
Supplemental Cash Flow Information

16. Supplemental Cash Flow Information

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

 

 

(in millions of dollars)

 

Interest paid

 

$

40.5

 

 

$

43.8

 

 

$

45.7

 

Non-cash investing and financing activities (included in Accounts payable):

 

 

 

 

 

 

 

 

 

Unpaid purchases of property and equipment

 

$

19.6

 

 

$

19.3

 

 

$

28.9

 

 

 

 

 

 

 

 

 

 

Supplemental lease disclosures:

 

 

 

 

 

 

 

 

 

Operating lease liabilities arising from obtaining operating lease assets

 

$

2.6

 

 

$

3.2

 

 

$

3.1

 

Cash paid for amounts included in the measurement of
   operating lease liabilities

 

$

8.2

 

 

$

9.3

 

 

$

9.8

 

Finance lease liabilities arising from obtaining finance lease assets

 

$

2.9

 

 

$

10.0

 

 

$

1.0

 

 

 

 

 

 

 

 

 

 

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

 

 

(in millions of dollars)

 

Components of cash, cash equivalents and restricted cash:

 

 

 

 

 

 

 

 

 

Cash and cash equivalents

 

$

18.4

 

 

$

82.4

 

 

$

57.4

 

Restricted cash included in Other assets

 

 

19.5

 

 

 

18.3

 

 

 

13.9

 

Total cash, cash equivalents and restricted cash presented on our Statements of
   Consolidated Cash Flows

 

$

37.9

 

 

$

100.7

 

 

$

71.3

 
v3.25.0.1
Business, Product and Geographical Area Information and Concentration of Risk
 12 Months Ended
Dec. 31, 2024
Segment Reporting [Abstract]  
Business, Product and Geographical Area Information and Concentration of Risk

17. Business, Product and Geographical Area Information and Concentration of Risk

 

Our primary line of business is the production of semi-fabricated specialty aluminum mill products, such as plate and sheet, bare and coated coils, and extruded and drawn products, primarily used in our Aero/HS Products, Packaging, GE Products, Automotive Extrusions and Other products end markets. We operate production facilities in the United States and Canada. Our Chairman, President and Chief Executive Officer is the chief operating decision maker (“CODM”) who evaluates our business as a single operating segment and makes decisions on resource allocations based on Net income (loss). The CODM uses Net income (loss) to evaluate income generated from the segment in deciding whether to reinvest profits into the segment or into other parts of the entity, such as for acquisitions or to pay dividends.

The following table provides the significant segment expenses that are provided to the CODM (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Net sales

 

$

3,024.0

 

 

$

3,087.0

 

 

$

3,427.9

 

 

 

 

 

 

 

 

 

 

Less:

 

 

 

 

 

 

 

 

 

Cost of products sold, excluding depreciation and amortization

 

 

 

 

 

 

 

 

 

Hedged cost of alloyed metal1

 

 

1,567.8

 

 

 

1,621.1

 

 

 

2,045.2

 

Manufacturing costs2

 

 

805.2

 

 

 

809.9

 

 

 

773.0

 

Plant overhead3

 

 

170.5

 

 

 

164.6

 

 

 

162.3

 

Freight costs

 

 

91.6

 

 

 

103.3

 

 

 

125.5

 

Other cost of products sold4

 

 

56.0

 

 

 

56.0

 

 

 

74.2

 

Depreciation and amortization

 

 

116.4

 

 

 

108.6

 

 

 

106.9

 

Selling, general, administrative, research and development

 

 

 

 

 

 

 

 

 

Research and development costs

 

 

2.2

 

 

 

2.9

 

 

 

1.9

 

Employee costs5

 

 

83.3

 

 

 

80.0

 

 

 

69.9

 

Other selling, general and administrative costs6

 

 

35.3

 

 

 

39.8

 

 

 

39.1

 

Goodwill impairment

 

 

—

 

 

 

—

 

 

 

20.5

 

Restructuring costs

 

 

7.6

 

 

 

5.0

 

 

 

2.2

 

Other operating charges, net

 

 

0.4

 

 

 

—

 

 

 

3.2

 

Interest expense

 

 

43.7

 

 

 

46.9

 

 

 

48.3

 

Other income, net – Note 13

 

 

(19.5

)

 

 

(7.4

)

 

 

(6.4

)

Income tax provision (benefit)

 

 

16.7

 

 

 

9.1

 

 

 

(8.3

)

Net income (loss)

 

$

46.8

 

 

$

47.2

 

 

$

(29.6

)
1.
Hedged cost of alloyed metal includes cost of aluminum at the Midwest transaction price and the cost of alloying elements used in the production process. This metric also includes metal price exposure on shipments that we hedged with realized losses upon settlement of $0.2 million, $21.4 million, and $17.0 million in 2024, 2023, and 2022, respectively.
2.
Manufacturing costs primarily includes labor, utilities, supplies and other materials, excluding alloys incurred at our various production facilities.
3.
Plant overhead includes salaried employee costs, property taxes, and insurance associated with our various production facilities.
4.
Other costs of products sold primarily includes lease expense, accretion expense related to CAROs, and major maintenance costs.
5.
Employee costs include salaries, benefits, and incentive compensation.
6.
Other selling, general and administrative costs primarily includes professional services, computer hardware and software costs, office rent, and utilities.

The CODM does not review asset and capital expenditure information by reportable operating segment as such information is presented to the CODM on a consolidated basis.

The following table presents Net sales by end market applications and by timing of control transfer (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Net sales:

 

 

 

 

 

 

 

 

 

Aero/HS Products

 

$

883.0

 

 

$

899.3

 

 

$

676.1

 

Packaging

 

 

1,260.9

 

 

 

1,315.2

 

 

 

1,585.3

 

GE Products

 

 

618.1

 

 

 

596.5

 

 

 

883.8

 

Automotive Extrusions

 

 

251.9

 

 

 

254.9

 

 

 

254.8

 

Other products

 

 

10.1

 

 

 

21.1

 

 

 

27.9

 

Total net sales

 

$

3,024.0

 

 

$

3,087.0

 

 

$

3,427.9

 

 

 

 

 

 

 

 

 

 

Timing of revenue recognition:

 

 

 

 

 

 

 

 

 

Products transferred at a point in time

 

$

2,326.5

 

 

$

2,394.8

 

 

$

2,782.9

 

Products transferred over time

 

 

697.5

 

 

 

692.2

 

 

 

645.0

 

Total net sales

 

$

3,024.0

 

 

$

3,087.0

 

 

$

3,427.9

 

 

The following table presents geographic information for net sales based on country of origin, income taxes paid, and long-lived assets (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Net sales to unaffiliated customers:

 

 

 

 

 

 

 

 

 

Domestic

 

$

2,920.0

 

 

$

2,986.0

 

 

$

3,328.2

 

Foreign1

 

 

104.0

 

 

 

101.0

 

 

 

99.7

 

Total net sales

 

$

3,024.0

 

 

$

3,087.0

 

 

$

3,427.9

 

Income taxes paid:

 

 

 

 

 

 

 

 

 

Domestic

 

$

1.3

 

 

$

0.3

 

 

$

3.1

 

Foreign

 

 

3.1

 

 

 

0.2

 

 

 

3.2

 

Total income taxes paid

 

$

4.4

 

 

$

0.5

 

 

$

6.3

 

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Long-lived assets:2

 

 

 

 

 

 

 

 

 

Domestic

 

$

1,134.5

 

 

$

1,025.3

 

 

$

984.8

 

Foreign1

 

 

26.7

 

 

 

26.8

 

 

 

28.4

 

Total long-lived assets

 

$

1,161.2

 

 

$

1,052.1

 

 

$

1,013.2

 

 

1.
Foreign reflects our London, Ontario production facility.
2.
Long-lived assets represent Property, plant and equipment, net.

The aggregate foreign currency transaction loss included in determining Net income (loss) was $0.3 million and $0.5 million for 2024 and 2022, respectively. The aggregate foreign currency transaction gain included in determining Net income was immaterial for 2023.

Concentrations. For the years ended December 31, 2024, December 31, 2023, and December 31, 2022, one customer represented 16%, 18%, and 19%, respectively, of Net sales, and a second customer represented 15%, 16%, and 14%, respectively, of Net sales.

One customer accounted for 17%, a second customer accounted for 17%, and a third customer accounted for 15% of the accounts receivable balance at December 31, 2024. One customer accounted for 20%, a second customer accounted for 13%, and a third customer accounted for 12% of the accounts receivable balance at December 31, 2023.

The following table presents information about export sales and primary aluminum supply from our major suppliers:

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Percentage of Net sales:

 

 

 

 

 

 

 

 

 

Export sales

 

 

10

%

 

 

10

%

 

 

10

%

 

 

 

 

 

 

 

 

 

Percentage of total annual primary aluminum supply (lbs):

 

 

 

 

 

 

 

 

 

Supply from our top five major suppliers

 

 

80

%

 

 

83

%

 

 

81

%

Supply from our largest supplier

 

 

21

%

 

 

37

%

 

 

48

%

Supply from our second and third largest suppliers combined

 

 

38

%

 

 

28

%

 

 

20

%

 

At December 31, 2024, approximately 65% of our employees were covered by collective bargaining agreements. In February 2025, the collective bargaining agreements expiring in 2025 (representing 39% of the covered employees) were renewed through September 2030 (see Note 18).
v3.25.0.1
Subsequent Events
 12 Months Ended
Dec. 31, 2024
Subsequent Events [Abstract]  
Subsequent Events

18. Subsequent Events

Dividend Declaration. On January 14, 2025, we announced that our Board of Directors declared a quarterly cash dividend of $0.77 per common share. As such, we paid approximately $12.7 million (including dividend equivalents) on February 14, 2025 to stockholders of record and the holders of certain restricted stock units at the close of business on January 24, 2025.

Collective Bargaining Agreement Renewal. In February 2025, the Company and the USW ratified new five-year collective bargaining agreements covering approximately 1,000 employees primarily located at our Trentwood and Newark facilities, and a separate agreement with the USW for another operation related to Trentwood. While the term of the current agreements ends on September 30, 2025, the new agreements will take effect upon expiration of the current agreements with a term ending on September 30, 2030. The entry into the new collective bargaining agreements did not have an impact on the Company’s consolidated financial statements for the year ended December 31, 2024.
v3.25.0.1
Summary of Significant Accounting Policies (Policies)
 12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]  
Organization and Nature of Operations

Organization and Nature of Operations. Kaiser Aluminum Corporation specializes in the production of semi-fabricated specialty aluminum mill products, such as aluminum plate and sheet, bare and coated coil and extruded and drawn products, for the following end market applications: (i) Aero/HS Products; (ii) Packaging; (iii) GE Products; (iv) Automotive Extrusions; and (v) Other products. Our business is organized into one operating segment. See Note 17 for additional information regarding our business, product and geographical area information and concentration of risk.
Principles of Consolidation and Basis of Presentation

Principles of Consolidation and Basis of Presentation. Our consolidated financial statements include the accounts of our wholly owned subsidiaries and are prepared in accordance with GAAP and the rules and regulations of the SEC. Intercompany balances and transactions are eliminated. We have reclassified certain items in prior periods to conform to current classifications.
Use of Estimates in the Preparation of Financial Statements

Use of Estimates in the Preparation of Financial Statements. The preparation of financial statements in accordance with GAAP requires the use of estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities known to exist as of the date the financial statements are published and the reported amounts of revenues and expenses during the reporting period. Uncertainties with respect to such estimates and assumptions are inherent in the preparation of our consolidated financial statements; accordingly, it is possible that the actual results could differ from these estimates and assumptions, which could have a material effect on the reported amounts of our consolidated financial position and results of operations.
Supply Chain Financing

Supply Chain Financing. We have several supply chain financing arrangements, in which we may sell certain of our customers’ trade accounts receivable to such customers’ financial institutions without recourse. We sell our undivided interests in certain of these receivables at our discretion when we determine that the cost of these arrangements is less than the cost of servicing our receivables with existing debt. Under the terms of the agreements, we retain no rights or interest, have no obligations with respect to the sold receivables and do not service the receivables after the sale. As such, we account for these transactions as a sale (see Note 13).
Fair Value Measurement

Fair Value Measurements. We apply the fair value hierarchy established by GAAP for the recognition and measurement of certain financial assets and liabilities. An asset or liability’s fair value classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. In determining fair value, we utilize valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible and consider counterparty risk in our assessment of fair value. We also review the underlying inputs that are significant to the fair value measurement of financial instruments to determine if a transfer among hierarchy levels is appropriate.

Financial assets and liabilities that we measure at fair value each period include our derivative instruments and equity investments related to our deferred compensation plan (see Note 5 and Note 8). Additionally, we measure at fair value once each year at December 31 the plan assets of our defined benefit pension and postretirement plans including the Salaried VEBA (see Note 5). In determining the fair value of the plan assets at an annual period end, we utilize primarily the results of valuations supplied by the investment advisors responsible for managing the assets of each plan, which we independently review for reasonableness. We record our remaining financial assets and liabilities at carrying value.

For a majority of our remaining non-financial assets and liabilities, which include inventories, debt issuance costs, and property, plant and equipment, we are not required to measure their fair value on a recurring basis. However, if certain triggering events occur, an evaluation of the affected non-financial asset or liability will be required, which could result in a reduction to the carrying amount of such asset or liability. See “Property, Plant and Equipment, Net” below for a discussion of impairment charges on long-lived physical assets. See Note 9 for the fair value of our Long-term debt, net.
Goodwill and Intangible Assets Goodwill is tested for impairment during the fourth quarter on an annual basis, as well as on an interim basis, as warranted, at the time of relevant events and changes in circumstances. Our policy around goodwill impairment testing permits us to perform a qualitative assessment or a quantitative goodwill impairment test. If a qualitative assessment is performed, we are not required to perform the quantitative goodwill impairment test unless we determine that, based on that qualitative assessment, it is more likely than not that our fair value is less than the carrying value. We performed our annual testing of goodwill impairment by applying the qualitative assessment as of October 1, 2024. For the current year evaluation, we assessed various assumptions, events and circumstances that would have affected the estimated fair value of the reporting unit under the qualitative assessment. The results of the qualitative assessment indicated that it is not more likely than not that the fair values of our reporting units were less than the carrying value.

Intangible asset fair values and useful lives are determined using the income approach valuation methodology. The income approach incorporates the use of cash flow projections and a discount rate that are developed using market participant-based assumptions. The cash flow projections are based on, among other factors, the expected future period of benefit of the asset, the various characteristics of the asset, long‑term forecasts of the business, market prices, projected cash flows and the rate used in discounting those cash flows. Intangible assets

with definite lives are initially recognized at fair value and subsequently amortized over the estimated useful lives to reflect the pattern in which the economic benefits of the intangible assets are consumed. In the event the pattern cannot be reliably determined, we use a straight-line amortization method. Whenever events or changes in circumstances indicate that the carrying amount of the intangible assets may not be recoverable, the intangible assets are reviewed for impairment. See Note 4 for discussion on goodwill and intangible assets.
Government Grants

Government Grants. From time to time, we receive grants from certain governmental agencies such as states and municipalities. We recognize government grants when we have reasonable assurance that we will comply with any conditions attached to the grant and the grant will be received. Government grants related to property, plant and equipment are presented as a reduction to the related asset’s carrying amount. Grants related to compensation for expenses already incurred or for immediate financial support with no future related costs are recognized as income in the period in which they are receivable. The following table presents the total government assistance recognized during the year ended December 31, 2024 (in millions of dollars):

 

Grantor

 

Grant

 

Amount

 

 

Duration

 

Classification

Indiana Economic Development Corporation

 

IN EDGE Tax Credit

 

$

1.6

 

 

2021 - 2030

 

Cost of products sold, excluding depreciation and amortization

Total

 

 

 

$

1.6

 

 

 

 

 

To be eligible to receive and keep the full amount of the IN EDGE Tax Credit, we must achieve: (i) minimum cumulative expenditures towards capital expenditures and (ii) a minimum number of full-time employees.
Cash and Cash Equivalents

Cash and Cash Equivalents. We consider only those short-term, highly liquid investments which, when purchased, have maturities of 90 days or less to be cash equivalents. Our cash equivalents consist primarily of funds in money market deposit accounts.
Restricted Cash

Restricted Cash. We are required to keep on deposit certain amounts that are pledged or held as collateral relating to workers’ compensation and other agreements. We account for such deposits as restricted cash (see Note 16). From time to time, such restricted funds could be returned to us or we could be required to pledge additional cash.
Trade Receivables and Allowance for Credit Losses

Trade Receivables and Allowance for Credit Losses. Trade receivables primarily consist of amounts billed to customers for products sold. Accounts receivable are generally due within 30 to 90 days. For the majority of our receivables, we establish an allowance for credit losses based upon collection experience and other factors including, but not limited to, customer credit ratings, bankruptcy filings, published or estimated credit default rates, age of receivables, expected loss rates, and collateral exposures. On certain other receivables where we are aware of a specific customer’s inability or reluctance to pay, an allowance for credit losses is established against amounts due, to reduce the net receivable balance to the amount we reasonably expect to collect. However, if circumstances change, our estimate of the recoverability of accounts receivable could be different. Circumstances that could affect our estimates include, but are not limited to, customer credit issues and general economic conditions. Accounts are written off once deemed to be uncollectible. Any subsequent cash collections relating to accounts that have been previously written off are typically recorded as a reduction to total bad debt expense in the period of payment. Write-offs for 2024, 2023, and 2022 were immaterial to our consolidated financial statements.
Inventories

Inventories. Inventories are stated at the lower of cost or market value. Finished products, work-in-process, and raw material inventories are stated on the LIFO basis. At December 31, 2024 and December 31, 2023, the cost of our inventory on a FIFO basis, which approximates the current replacement cost, exceeded its stated LIFO value by $96.8 million and $56.0 million, respectively. Other inventories are stated on the FIFO basis and consist of operating supplies, which are materials and supplies to be consumed during the production process. Inventory costs consist of material, labor, and manufacturing overhead, including depreciation. Abnormal costs, such as idle facility expenses, freight, handling costs, and spoilage, are accounted for as current period charges. See Note 2 for the components of inventories.

Replacement Parts. Replacement parts consist of equipment spare parts, which are stated on the FIFO basis. Replacement parts are recorded within Prepaid expenses and other current assets or Other assets depending on whether the expected utilization of the replacement parts is to occur within the next 12 months.
Property, Plant and Equipment, Net

Property, Plant and Equipment, Net. Property, plant and equipment, net, is recorded at cost and includes construction in progress (see Note 2). Interest related to the construction of qualifying assets is capitalized as part of the construction costs (see Note 9).

Depreciation is computed using the straight-line method at rates based on the estimated useful lives of the various classes of assets. Depreciable finance lease assets and leasehold improvements are amortized on a straight-line basis over the shorter of the estimated useful lives of the assets or the lease term. The estimated useful lives are as follows:

 

 

 

Range
(in years)

Land improvements

 

1-25

Buildings and leasehold improvements

 

2-45

Machinery and equipment

 

1-22

Depreciable finance lease assets

 

2-120

 

Depreciation expense is included in Depreciation and amortization within our Statements of Consolidated Income (Loss).

Property, plant and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset or group of assets may not be recoverable. We regularly assess whether events and circumstances with the potential to trigger impairment have occurred and rely on a number of factors, including operating results, business plans, economic projections, and anticipated future cash flow, to make such assessments. We use an estimate of the future undiscounted cash flows of the related asset or asset group over the estimated remaining life of such asset or asset group in measuring whether the asset or asset group is recoverable.

We recorded an impairment charge of $0.4 million on land classified as held for sale during 2024. There were no impairment charges in 2023 and 2022. Asset impairment charges are included in Other operating charges, net, in our Statements of Consolidated Income (Loss).

We classify assets as held for sale only when an asset is being actively marketed and expected to sell within 12 months. Assets held for sale are initially measured at the lesser of the assets’ carrying amount and the fair value less costs to sell.
Leases

Leases. We determine whether an agreement is a lease at inception. We have operating and finance leases for equipment and real estate that primarily have fixed lease payments. For purposes of calculating lease liabilities, options to extend or terminate a lease are included within the lease term when it is reasonably certain that we will exercise such options. Short-term leases with an initial term of 12 months or less are not recorded on our Consolidated Balance Sheets.

As most of our leases do not provide an implicit rate, we use information available at the lease commencement date in determining an incremental borrowing rate when calculating our right-of-use lease assets and liabilities. In determining the inputs to the incremental borrowing rate calculation, we make judgments about the value of the leased asset, our credit rating, and the lease term, including the probability of our exercising options to extend or terminate the underlying lease. Additionally, we make judgments around contractual asset substitution rights in determining whether a contract contains a lease.

We have lease agreements with lease and non-lease components, which are generally accounted for separately. These non-lease components include items such as common area maintenance, taxes, and insurance for our real estate leases, as well as maintenance charges related to our equipment leases. We have, however, applied the practical expedient within ASC No. 2016-02, Leases (Topic 842): Amendments to the Financial Accounting Standards Board Accounting Standards Codification, to not separate lease and non-lease components to our embedded supply system equipment leases and have therefore accounted for both lease and non‑lease components in determining the lease assets and liabilities.

Many of our equipment leases contain clauses that require us to return the equipment with certain functionality intact. We account for these costs as residual value guarantees when the guarantee becomes probable of being owed. Our lease agreements do not contain any material restrictive covenants.
Derivative Financial Instruments

Derivative Financial Instruments. Consistent with guidelines established by management and approved by our Board of Directors, we use derivative financial instruments to mitigate our exposure to changes in the market price of aluminum, certain alloying metals, energy, and foreign currency exchange rates. We do not use derivative financial instruments for trading or other speculative purposes. Hedging transactions are executed centrally on behalf of all of our operations to minimize transaction costs, monitor consolidated net exposures, and allow for increased responsiveness to changes in market factors.

We reflect the fair value of all of our derivative instruments on our Consolidated Balance Sheets. The fair value of hedges settling within one year is included in Prepaid expenses and other current assets or Other accrued liabilities. The fair value of hedges settling beyond one year is included in Other assets or Long-term liabilities. Cash flows related to all of our derivative instruments are reported in our Statements of Consolidated Cash Flows within the same category as the items being hedged. See Note 8 for additional information on our derivative financial instruments.
Self Insurance of Workers' Compensation and Employee Healthcare Liabilities

Self-Insurance of Workers’ Compensation and Employee Healthcare Liabilities. We self-insure the majority of the costs of workers’ compensation benefits and employee healthcare benefits and rely on insurance coverage to protect us from large losses on individual claims. Workers’ compensation liabilities are based on a combination of estimates for incurred-but-not-reported claims and the ultimate expense of incurred claims. Such estimates are based on judgment, using our historical claims data and information and analysis provided by actuarial and claims advisors, our insurance carriers, and other professionals. Accrued liabilities for employee healthcare benefits, which are estimates of unpaid incurred medical and prescription drug costs as provided by our healthcare administrators, were $7.8 million and $7.7 million at December 31, 2024 and December 31, 2023, respectively.
Deferred Issuance Costs

Debt Issuance Costs. Costs incurred in connection with debt financing are deferred and amortized over the estimated term of the related borrowing. Such amortization is included in Interest expense in our Statements of Consolidated Income (Loss). Unamortized issuance costs are presented within Long-term debt, net on our Consolidated Balance Sheets (see Note 9).
Conditional Asset Retirement Obligations ("CAROs")

Conditional Asset Retirement Obligations (“CAROs”). We have CAROs at several of our manufacturing facilities. Our CAROs can be separated into two primary categories: (i) legal obligations related to the removal and disposal of asbestos and (ii) CAROs related to future lease terminations. The majority of our CAROs relate to the first category and consist of incremental costs that would be associated with the removal and disposal of asbestos (all of which is believed to be fully contained and encapsulated within walls, floors, roof, piping, or equipment insulation) of certain of our older facilities if such facilities were to undergo major renovation or be demolished. We estimate incremental costs for special handling, removal and disposal costs of materials that may or will give rise to CAROs and then discount the expected costs back to the current year using a credit-adjusted, risk-free rate. When it is unclear when or if CAROs will be triggered, we use probability weighting for possible timing scenarios to determine the probability-weighted liability amounts that should be recognized in our consolidated financial statements (see Note 10).
Environmental Contingencies

Environmental Contingencies. With respect to environmental loss contingencies, we record a loss contingency whenever a contingency is probable and reasonably estimable (see Note 10). Accruals for estimated losses from environmental remediation obligations are generally recognized no later than the completion of the remedial feasibility study. Such accruals are adjusted as information develops or circumstances change. Costs of future expenditures for environmental remediation obligations are not discounted to their present value. Accruals for expected environmental costs are included in Other accrued liabilities or Long-term liabilities, as appropriate (see Note 2). Environmental expense relating to continuing operations is included in COGS in our Statements of Consolidated Income (Loss). Environmental expense relating to non-operating locations is included in Selling, general, administrative, research and development (“SG&A and R&D”) in our Statements of Consolidated Income (Loss).
Revenue Recognition

Revenue Recognition. We recognize revenue as we fulfill our performance obligations and transfer control of products to our customers. For products that have an alternative use and/or for which we do not have an enforceable right to payment (including a reasonable profit) during the production process, we recognize revenue at a point in time. For products that have no alternative use and for which we have an enforceable right to payment (including a reasonable profit) throughout the production process, we recognize revenue over time. In general, revenue recognized over time primarily relates to our Aero/HS Products and our Automotive Extrusions with the remainder of our products recognized at a point in time. In limited circumstances, we have concluded that we are an agent in certain Packaging end market arrangements. For these transactions, revenue has been recognized on a net basis.

For the majority of our business, contracts with customers begin when we acknowledge a purchase order for a specific customer order of product to be delivered in the near term. These purchase orders are short-term in nature, although they may reference a longer term “blanket purchase order” or a “terms and conditions” agreement, both of which may span multiple years. For revenue recognized at a point in time, transfer of control usually occurs upon shipment or upon customer receipt of the product, depending on shipping terms. For contracts recognized over time, control transfer occurs incrementally during our production process as progress is made on fulfilling the performance obligation. We use the input method of determining our progress, capturing direct costs beginning at the point that billet or cast ingot is introduced into production at either the extrusion phase or the rolling phase, respectively. We believe the input method more accurately reflects the transfer of control as it represents the best information available of work completed to date for which we have an enforceable right to payment. For products in production, we recognize revenue using estimates of the cost incurred to date plus a reasonable margin. As the duration of our contracts for accounting purposes is typically less than one year, we do not present quantitative information about the aggregate transaction price allocated to unsatisfied performance obligations at the end of the reporting period.

We adjust the amount of revenue recognized on all products, regardless of timing of revenue recognition, for variable price consideration, which could include metal market price adjustments, volume rebates and sales discounts. We estimate rebate and discount values based on forecasted order data and historical payment trends for specific customers, adjusted as necessary at each reporting period. Accounts receivable is recorded when our right to consideration becomes unconditional. We do not adjust the promised amount of consideration for the effects of a significant financing component as we do not expect the period between the transfer of control of products to our customers and receipt of payment will be greater than one year.

Contract assets primarily relate to our enforceable right to consideration for work completed but not billed at the reporting date on contracts for products recognized over time. Contract assets also include amounts related to our contractual right to consideration for finished goods recognized over time that were in transit as of period end.

Incremental Costs of Obtaining a Contract. We expense the costs of obtaining a contract as incurred as the amortization period of the asset that we otherwise would have recognized is one year or less.
Shipping and Handling Activities

Shipping and Handling Activities. We account for shipping and handling activities that occur after the customer has obtained control of a product as fulfillment activities (i.e., an expense) rather than as a promised service (i.e., a revenue element).
Advertising Costs

Advertising Costs. Advertising costs, which are included in SG&A and R&D, are expensed as incurred. Advertising costs for 2024 and 2023 were $0.4 million and $0.1 million, respectively. We had no advertising costs in 2022.
Research and Development Costs

Research and Development Costs. Research and development costs, which are included in SG&A and R&D, are expensed as incurred. Research and development costs, inclusive of personnel costs, for 2024, 2023, and 2022 were $12.0 million, $11.1 million and $9.3 million, respectively.
Stock-Based Compensation

Stock-Based Compensation. Stock-based compensation in the form of service-based awards is provided to executive officers, certain employees and non-employee directors and is accounted for at fair value. We measure the cost of services received in exchange for an award of equity instruments based on the grant-date fair value of the award and the number of awards expected to ultimately vest. The grant-date fair value is determined based on the stock price on the date of grant, adjusted for expected dividends or dividend equivalents to be paid during the vesting period.

We also grant performance-based awards to executive officers and other key employees. The methodology used to value these performance-based awards is based on the nature of the performance conditions within those awards. Awards that are subject to performance conditions pertaining to total shareholder return (market-based awards) are valued on the date of grant using a Monte Carlo valuation model. The key assumptions in applying this model are an expected volatility and a risk-free interest rate. Awards with certain other performance conditions (non-market-based awards) are valued based on our stock price at the date of grant. Our non‑market-based awards have performance conditions pertaining to our cost performance and Adjusted EBITDA margin performance, which is measured by our Adjusted EBITDA as a percentage of Conversion Revenue, which is Net sales less the Hedged Cost of Alloyed Metal. As used in this discussion, “Hedged Cost of Alloyed Metal” is the cost of aluminum at the average MWTP plus the cost of alloying elements and any realized gains and/or losses on settled hedges related to the metal sold in the referenced period. Holders of performance-based awards receive a one-time payment at the time of issuance of vested shares based on the total dividends they would have received if the vested shares had been held of record from the date of grant through the date of issuance. See Note 7 for more information on our stock-based compensation.

The cost of service-based awards, including time-vested restricted stock and performance shares, is recognized as an expense over the requisite service period of the award on a straight-line basis. Adjustments to expense related to forfeitures are recorded in the period in which they occur. We recognize stock-based compensation expense for market-based awards if the requisite service period is rendered, even if the market condition is never satisfied. For performance shares with performance conditions pertaining to our cost performance and Adjusted EBITDA margin performance, the related expense is updated quarterly by adjusting the estimated number of shares expected to vest based on the most probable outcome of the performance condition (see Note 7).
New Accounting Pronouncements

Adoption of New Accounting Pronouncements

Segment Reporting. In November 2023, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2023-07 (“ASU 2023-07”), Improvements to Reportable Segment Disclosures. The guidance primarily requires enhanced disclosures about significant segment expenses. All disclosure requirements under ASU 2023-07 and existing segment disclosures in ASC 280, Segment Reporting are also

required for public entities with a single reportable segment. There were no material impacts on our consolidated financial statements resulting from our adoption of ASU 2023-07. See Note 17 for the required disclosures related to our adoption of ASU 2023-07.
Accounting Pronouncements Issued But Not Yet Adopted

Accounting Pronouncements Issued But Not Yet Adopted

Disclosure Improvements. In October 2023, the FASB issued ASU No. 2023-06 (“ASU 2023-06”), Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative. The guidance amends GAAP to reflect updates and simplifications to certain disclosure requirements referred to the FASB by the SEC. The amendments in ASU 2023-06 will become effective on the date which the SEC’s removal of the related disclosure becomes effective. If by June 30, 2027, the SEC does not remove the related disclosure, the pending amendment will be removed from ASC 2023-06 and it will not be effective. We do not expect this ASU to have a material impact on our consolidated financial statements.

Income Taxes. In December 2023, the FASB issued ASU No. 2023-09 (“ASU 2023-09”), Improvements to Income Tax Disclosures. The guidance is primarily intended to improve income tax disclosure requirements by requiring (i) consistent categories and greater disaggregation of information in the rate reconciliation and (ii) the disaggregation of income taxes paid by jurisdiction. The guidance makes several other changes to the income tax disclosure requirements. The amendments in ASU 2023-09 are effective for fiscal years beginning after December 15, 2024, with early adoption permitted, and is required to be applied prospectively with the option of retrospective application. We plan to adopt the provisions of ASU 2023-09 in the fourth quarter of fiscal 2025 and do not expect this ASU to have a material impact on our consolidated financial statements.

Disaggregation of Income Statement Expenses. In November 2024, the FASB issued ASU No. 2024-03 (“ASU 2024-03”), Disaggregation of Income Statement Expenses. The guidance requires additional, disaggregated disclosure about certain income statement expense line items. The amendments in ASU 2024-03 are effective for annual reporting periods beginning after December 15, 2026 and interim reporting periods beginning after December 15, 2027, with early adoption permitted, and is required to be applied prospectively with the option of retrospective application. We plan to adopt the provisions of ASU 2024-03 in the fourth quarter of fiscal 2027 and continue to evaluate the disclosure requirements related to the new standard.
v3.25.0.1
Summary of Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]  
Schedule of Total Government Assistance Recognized The following table presents the total government assistance recognized during the year ended December 31, 2024 (in millions of dollars):

 

Grantor

 

Grant

 

Amount

 

 

Duration

 

Classification

Indiana Economic Development Corporation

 

IN EDGE Tax Credit

 

$

1.6

 

 

2021 - 2030

 

Cost of products sold, excluding depreciation and amortization

Total

 

 

 

$

1.6

 

 

 

 

 
Estimated Useful Lives of Property, Plant and Equipment

Depreciation is computed using the straight-line method at rates based on the estimated useful lives of the various classes of assets. Depreciable finance lease assets and leasehold improvements are amortized on a straight-line basis over the shorter of the estimated useful lives of the assets or the lease term. The estimated useful lives are as follows:

 

 

 

Range
(in years)

Land improvements

 

1-25

Buildings and leasehold improvements

 

2-45

Machinery and equipment

 

1-22

Depreciable finance lease assets

 

2-120
v3.25.0.1
Supplemental Balance Sheet Information (Tables)
 12 Months Ended
Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Schedule of Supplemental Balance Sheet Information

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

 

 

(In millions of dollars)

 

Trade Receivables, Net

 

 

 

 

 

 

Billed trade receivables

 

$

320.5

 

 

$

325.8

 

Allowance for doubtful receivables

 

 

(0.8

)

 

 

(0.6

)

Trade receivables, net

 

$

319.7

 

 

$

325.2

 

 

 

 

 

 

 

Inventories

 

 

 

 

 

 

Finished products

 

$

103.7

 

 

$

89.3

 

Work-in-process

 

 

193.3

 

 

 

210.8

 

Raw materials

 

 

192.8

 

 

 

161.5

 

Operating supplies

 

 

14.1

 

 

 

15.6

 

Inventories

 

$

503.9

 

 

$

477.2

 

 

 

 

 

 

 

Property, Plant and Equipment, Net

 

 

 

 

 

 

Land and improvements

 

$

37.2

 

 

$

38.0

 

Buildings and leasehold improvements

 

 

256.3

 

 

 

238.4

 

Machinery and equipment 1

 

 

1,337.4

 

 

 

1,265.3

 

Construction in progress

 

 

297.5

 

 

 

173.7

 

Property, plant and equipment, gross

 

 

1,928.4

 

 

 

1,715.4

 

Accumulated depreciation and amortization

 

 

(767.5

)

 

 

(663.7

)

Land held for sale

 

 

0.3

 

 

 

0.4

 

Property, plant and equipment, net

 

$

1,161.2

 

 

$

1,052.1

 

 

 

 

 

 

 

Other Assets

 

 

 

 

 

 

Assets to be conveyed associated with Warrick acquisition 1

 

$

18.3

 

 

$

56.8

 

Restricted cash – Note 16

 

 

19.5

 

 

 

18.3

 

Long-term replacement parts

 

 

18.3

 

 

 

16.7

 

Other

 

 

22.5

 

 

 

25.9

 

Other assets

 

$

78.6

 

 

$

117.7

 

.

 

 

 

 

 

 

Other Accrued Liabilities

 

 

 

 

 

 

Uncleared cash disbursements

 

$

24.5

 

 

$

15.7

 

Accrued income taxes and other taxes payable

 

 

11.2

 

 

 

9.5

 

Accrued annual contribution to Salaried VEBA – Note 5

 

 

0.7

 

 

 

1.1

 

Accrued interest

 

 

9.9

 

 

 

9.9

 

Short-term environmental accrual – Note 10

 

 

0.7

 

 

 

2.8

 

Current operating lease liabilities – Note 3

 

 

6.3

 

 

 

8.0

 

Current finance lease liabilities – Note 3

 

 

2.4

 

 

 

2.1

 

Current deferred compensation plan liabilities - Note 5

 

 

6.7

 

 

 

0.4

 

Other – Note 8

 

 

17.0

 

 

 

14.8

 

Other accrued liabilities

 

$

79.4

 

 

$

64.3

 

 

 

 

 

 

 

Long-Term Liabilities

 

 

 

 

 

 

Workers' compensation accrual

 

$

26.8

 

 

$

29.9

 

Long-term environmental accrual – Note 10

 

 

17.7

 

 

 

14.2

 

Other long-term liabilities

 

 

39.5

 

 

 

37.6

 

Long-term liabilities

 

$

84.0

 

 

$

81.7

 

 

1.
During the year ended December 31, 2024, $38.5 million of certain assets associated with our acquisition of Warrick were conveyed to us and placed in service. At December 31, 2024, such assets are presented within Machinery and equipment.
v3.25.0.1
Leases (Tables)
 12 Months Ended
Dec. 31, 2024
Leases [Abstract]  
Schedule of Lease Terms and Discount Rates

The following table summarizes key finance and operating lease terms and discount rates:

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

Weighted-average remaining lease term (in years):

 

 

 

 

 

 

Finance leases

 

 

36.9

 

 

 

38.8

 

Operating leases

 

 

8.9

 

 

 

8.9

 

Weighted-average discount rate:

 

 

 

 

 

 

Finance leases

 

 

5.40

%

 

 

5.31

%

Operating leases

 

 

4.69

%

 

 

4.35

%
Schedule of Lease Assets and Lease Liabilities

The following table summarizes the classification of lease assets and lease liabilities on our Consolidated Balance Sheets (in millions of dollars):

 

 

 

 

 

As of December 31,

 

Description

 

Classification

 

2024

 

 

2023

 

Operating lease assets

 

Operating lease assets

 

$

27.2

 

 

$

32.6

 

Finance lease assets

 

Property, plant and equipment, net

 

$

14.8

 

 

$

14.3

 

 

 

 

 

 

 

 

 

 

Current operating lease liabilities

 

Other accrued liabilities

 

$

6.3

 

 

$

8.0

 

Non-current operating lease liabilities

 

Long-term portion of operating lease liabilities

 

$

25.2

 

 

$

29.2

 

Total operating lease liabilities

 

 

 

$

31.5

 

 

$

37.2

 

 

 

 

 

 

 

 

 

 

Current finance lease liabilities

 

Other accrued liabilities

 

$

2.4

 

 

$

2.1

 

Non-current finance lease liabilities

 

Long-term liabilities

 

$

13.0

 

 

$

12.9

 

Total finance lease liabilities

 

 

 

$

15.4

 

 

$

15.0

 

 
Components of Lease Cost

The following table summarizes the components of lease cost in our Statements of Consolidated Income (Loss) (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Operating lease cost

 

$

10.2

 

 

$

11.6

 

 

$

12.1

 

Short-term lease cost

 

 

4.0

 

 

 

4.3

 

 

 

4.3

 

Finance lease cost:

 

 

 

 

 

 

 

 

 

Amortization of leased assets

 

 

2.4

 

 

 

2.4

 

 

 

2.5

 

Interest on lease liabilities

 

 

0.8

 

 

 

0.7

 

 

 

0.3

 

Total lease cost

 

$

17.4

 

 

$

19.0

 

 

$

19.2

 
Schedule of Maturity of Our Lease Liabilities

The following table presents the maturity of our lease liabilities as of December 31, 2024 (in millions of dollars):

 

 

 

Finance Leases

 

 

Operating Leases

 

2025

 

$

3.1

 

 

$

7.6

 

2026

 

 

2.5

 

 

 

5.1

 

2027

 

 

1.5

 

 

 

4.2

 

2028

 

 

1.0

 

 

 

3.8

 

2029

 

 

0.7

 

 

 

3.7

 

Thereafter

 

 

26.3

 

 

 

15.6

 

Total minimum lease payments

 

$

35.1

 

 

$

40.0

 

Less: interest

 

 

(19.7

)

 

 

(8.5

)

Present value

 

$

15.4

 

 

$

31.5

 
v3.25.0.1
Goodwill and Intangible Assets (Tables)
 12 Months Ended
Dec. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule of Goodwill

The following table presents the changes in the carrying value of our goodwill (in millions of dollars):

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

Gross carrying value1

 

$

57.7

 

 

$

57.7

 

Accumulated impairment loss1

 

 

(38.9

)

 

 

(38.9

)

Net carrying value

 

$

18.8

 

 

$

18.8

 
1.
The gross carrying value and accumulated impairment loss excludes $25.2 million of goodwill recorded in conjunction with our acquisition of IMT.
Schedule of Gross Carrying Amount and Accumulated Amortization By Major Intangible Asset Class The following table presents the gross carrying amount and accumulated amortization by major intangible asset class (in millions of dollars, except amortization periods):

 

 

 

Weighted-
Average
Amortization
Period
(in years)

 

 

Gross
Amount

 

 

Accumulated
Amortization

 

 

Intangible
Assets, Net

 

As of December 31, 2024

 

 

 

 

 

 

 

 

 

 

 

 

Customer relationships

 

 

19

 

 

$

68.1

 

 

$

(30.3

)

 

$

37.8

 

Trade name

 

 

10

 

 

 

2.4

 

 

 

(1.5

)

 

 

0.9

 

Non-compete agreement

 

 

5

 

 

 

5.4

 

 

 

(5.4

)

 

 

—

 

Favorable lease contracts

 

 

120

 

 

 

7.0

 

 

 

(0.2

)

 

 

6.8

 

Total

 

 

26

 

 

$

82.9

 

 

$

(37.4

)

 

$

45.5

 

As of December 31, 2023

 

 

 

 

 

 

 

 

 

 

 

 

Customer relationships

 

 

19

 

 

$

68.1

 

 

$

(26.1

)

 

$

42.0

 

Trade name

 

 

10

 

 

 

2.4

 

 

 

(1.2

)

 

 

1.2

 

Non-compete agreement

 

 

5

 

 

 

5.4

 

 

 

(5.4

)

 

 

—

 

Favorable lease contracts

 

 

120

 

 

 

7.0

 

 

 

(0.2

)

 

 

6.8

 

Total

 

 

26

 

 

$

82.9

 

 

$

(32.9

)

 

$

50.0

 
Schedule of Expected Amortization of Intangible Assets The following table presents the expected amortization of intangible assets for each of the next five calendar years and thereafter as of December 31, 2024 (in millions of dollars):

 

2025

 

$

4.5

 

2026

 

 

4.5

 

2027

 

 

4.5

 

2028

 

 

4.4

 

2029

 

 

4.1

 

Thereafter

 

 

23.5

 

Total

 

$

45.5

 
v3.25.0.1
Employee Benefits (Tables)
 12 Months Ended
Dec. 31, 2024
Retirement Benefits [Abstract]  
Schedule of Assumptions Used for Benefit Obligation

Key Assumptions. The following table presents the weighted average assumptions used to determine benefit obligations:

 

 

 

Pension Plans1

 

 

OPEB

 

 

Salaried VEBA

 

 

 

As of December 31,

 

 

As of December 31,

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

 

2024

 

 

2023

 

 

2024

 

 

2023

 

Discount rate

 

 

5.54

%

 

 

4.95

%

 

 

5.48

%

 

 

4.92

%

 

 

5.40

%

 

 

4.89

%

Rate of compensation increase

 

 

2.56

%

 

 

2.63

%

 

 

—

%

 

 

—

%

 

 

—

%

 

 

—

%

 

1.
Assumptions for our pension plans are weighted based on the total benefit obligations of each.
Schedule of Assumptions Used to Determine Net Periodic Postretirement and Postemployment Benefit Cost

The following table presents the weighted average assumptions used to determine net periodic postretirement and postemployment benefit cost:

 

 

 

Pension Plans1

 

 

OPEB

 

 

Salaried VEBA

 

 

 

Year Ended December 31,

 

 

Year Ended December 31,

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

 

2024

 

 

2023

 

 

2022

 

 

2024

 

 

2023

 

 

2022

 

Discount rate

 

 

5.00

%

 

 

5.19

%

 

 

2.90

%

 

 

4.92

%

 

 

5.14

%

 

 

2.64

%

 

 

4.89

%

 

 

5.10

%

 

 

2.49

%

Expected long-term return on plan assets2

 

 

6.31

%

 

 

6.33

%

 

 

6.02

%

 

 

—

%

 

 

—

%

 

 

—

%

 

 

5.75

%

 

 

5.75

%

 

 

5.50

%

Rate of compensation increase

 

 

2.56

%

 

 

2.63

%

 

 

2.69

%

 

 

—

%

 

 

—

%

 

 

—

%

 

 

—

%

 

 

—

%

 

 

—

%

 

1.
Assumptions for our pension plans are weighted based on the total benefit obligations of each.
2.
The expected long-term rate of return assumption for the Salaried VEBA is based on the targeted investment portfolios provided to us by the trustee of the Salaried VEBA.
Schedule of Changes in Benefit Obligations The following table presents the benefit obligations and funded status of our pension plans, OPEB, and the Salaried VEBA and the corresponding amounts that are included in our Consolidated Balance Sheets (in millions of dollars):

 

 

 

Pension Plans

 

 

OPEB

 

 

Salaried VEBA

 

 

 

As of December 31,

 

 

As of December 31,

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

 

2024

 

 

2023

 

 

2024

 

 

2023

 

Change in benefit obligation:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Obligation at beginning of year

 

$

30.5

 

 

$

18.8

 

 

$

68.8

 

 

$

66.4

 

 

$

46.9

 

 

$

58.9

 

Foreign currency translation adjustment

 

 

(0.5

)

 

 

0.2

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Service cost

 

 

3.6

 

 

 

3.8

 

 

 

1.1

 

 

 

1.1

 

 

 

—

 

 

 

—

 

Interest cost

 

 

1.6

 

 

 

1.3

 

 

 

3.3

 

 

 

3.4

 

 

 

2.2

 

 

 

2.9

 

Prior service cost (credit)1

 

 

2.2

 

 

 

6.6

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(8.8

)

Actuarial (gain) loss2

 

 

(1.6

)

 

 

0.2

 

 

 

(6.8

)

 

 

(0.7

)

 

 

(1.4

)

 

 

0.4

 

Plan participants contributions

 

 

0.1

 

 

 

0.1

 

 

 

0.2

 

 

 

0.1

 

 

 

—

 

 

 

—

 

Benefits paid

 

 

(0.7

)

 

 

(0.5

)

 

 

(1.9

)

 

 

(1.5

)

 

 

(4.8

)

 

 

(6.5

)

Settlements3

 

 

(4.5

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Obligation at end of year4

 

 

30.7

 

 

 

30.5

 

 

 

64.7

 

 

 

68.8

 

 

 

42.9

 

 

 

46.9

 

Change in plan assets:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fair market value of plan assets at beginning of year

 

 

20.5

 

 

 

14.9

 

 

 

—

 

 

 

—

 

 

 

43.1

 

 

 

42.4

 

Foreign currency translation adjustment

 

 

0.3

 

 

 

0.2

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Actual return on assets

 

 

0.9

 

 

 

1.4

 

 

 

—

 

 

 

—

 

 

 

3.9

 

 

 

6.1

 

Plan participants contributions

 

 

0.1

 

 

 

0.1

 

 

 

0.2

 

 

 

0.1

 

 

 

—

 

 

 

—

 

Company contributions

 

 

5.9

 

 

 

4.4

 

 

 

1.7

 

 

 

1.4

 

 

 

0.7

 

 

 

1.1

 

Benefits paid

 

 

(0.7

)

 

 

(0.5

)

 

 

(1.9

)

 

 

(1.5

)

 

 

(4.8

)

 

 

(6.5

)

Settlements3

 

 

(4.5

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Fair market value of plan assets at end of year

 

 

22.5

 

 

 

20.5

 

 

 

—

 

 

 

—

 

 

 

42.9

 

 

 

43.1

 

Net funded status5

 

$

(8.2

)

 

$

(10.0

)

 

$

(64.7

)

 

$

(68.8

)

 

$

—

 

 

$

(3.8

)

Cumulative gain (loss) recognized in Accumulated other comprehensive income:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Accumulated net actuarial gain

 

$

4.2

 

 

$

1.3

 

 

$

23.1

 

 

$

17.4

 

 

$

8.2

 

 

$

5.2

 

Prior service cost

 

 

(7.6

)

 

 

(6.1

)

 

 

—

 

 

 

—

 

 

 

(14.3

)

 

 

(16.0

)

Total

 

$

(3.4

)

 

$

(4.8

)

 

$

23.1

 

 

$

17.4

 

 

$

(6.1

)

 

$

(10.8

)

 

1.
The prior service cost relating to our pension plans in 2024 resulted from an amendment to the Kaiser Aluminum Warrick pension plan clarifying certain plan provisions going back to the date of our acquisition of Warrick. The prior service cost relating to our pension plans in 2023 resulted from a new four-year collective bargaining agreement with the USW Local 104. In connection with the agreement, we amended the Kaiser Aluminum Warrick pension plan to increase certain pension benefits for covered plan participants. The prior service credit relating to the Salaried VEBA in 2023 resulted from a decrease in the annual healthcare reimbursement benefit for plan participants.
2.
The actuarial gain relating to our pension plans in 2024 was comprised of a $2.2 million gain due to a change in the discount rate, partially offset by a $0.3 million loss due to changes in census information and a $0.3 million loss recognized in conjunction with a group annuity purchase. The actuarial loss relating to our pension plans in 2023 was comprised of a $0.5 million loss due to a change in the discount rate and a $0.3 million gain due to changes in census information. The actuarial gain relating to the OPEB in 2024 was comprised of a $6.5 million gain due to changes in census information, a $3.3 million gain due to a change in the discount rate, a $3.2 million gain due to a change in morbidity assumptions, a $3.3 million loss due to a change in the trend rate assumption, and a $2.9 million loss due to a change in the projected depletion year. The actuarial gain relating to the OPEB in 2023 was comprised of a $2.7 million gain due to a change in the projected depletion year, a $2.5 million gain due to changes in census information, a $3.1 million loss due to a change in the trend rate assumption, and a $1.4 million loss due to a change in the discount rate. The actuarial gain relating to the Salaried VEBA in 2024 was comprised of a $1.4 million gain due to a change in the discount rate, a $0.1 million gain due to changes in census information, and a $0.1 million loss due to a change in the trend rate assumption.
The actuarial loss relating to the Salaried VEBA in 2023 was comprised of a $0.7 million loss due to a change in the discount rate and a $0.3 million gain due to changes in census information.
3.
In the fourth quarter of 2024, we entered into a group annuity purchase agreement under which approximately $4.5 million of obligations for certain participants of the Kaiser Aluminum Canada Limited Retirement Plan for Salaried Employees were transferred to an insurance company. The annuitization was funded through existing plan assets and does not change the amount of the monthly pension benefits received by the affected participants.
4.
For the pension plans, the benefit obligation is the projected benefit obligation. For the Salaried VEBA and OPEB, the benefit obligation is the APBO.
5.
At December 31, 2024, Net funded status relating to the pension plans consisted of $1.6 million within Other assets and $9.8 million within Pension and OPEB on our Consolidated Balance Sheets. At December 31, 2023, Net funded status relating to the pension plans consisted of $1.3 million within Other assets and $11.3 million within Pension and OPEB on our Consolidated Balance Sheets. Of the Net funded status relating to the OPEB at December 31, 2024, $3.1 million was included within Accrued salaries, wages and related expenses and $61.6 million was included within Pension and OPEB on our Consolidated Balance Sheets. Of the Net funded status relating to the OPEB at December 31, 2023, $3.3 million was included within Accrued salaries, wages and related expenses and $65.5 million was included within Pension and OPEB on our Consolidated Balance Sheets. Net funded status relating to the Salaried VEBA at December 31, 2024 and December 31, 2023 was included within Net liabilities of Salaried VEBA on our Consolidated Balance Sheets.
Schedule of Expected Benefit Payments

The following table presents the net benefits expected to be paid (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2025

 

 

2026

 

 

2027

 

 

2028

 

 

2029

 

 

2030-2034

 

Pension benefit payments

 

$

0.7

 

 

$

0.9

 

 

$

1.1

 

 

$

1.3

 

 

$

1.7

 

 

$

11.7

 

Salaried VEBA benefit payments1

 

 

5.3

 

 

 

5.1

 

 

 

4.9

 

 

 

4.6

 

 

 

4.3

 

 

 

16.9

 

OPEB payments

 

 

3.1

 

 

 

3.8

 

 

 

4.4

 

 

 

5.1

 

 

 

5.8

 

 

 

34.8

 

Total

 

$

9.1

 

 

$

9.8

 

 

$

10.4

 

 

$

11.0

 

 

$

11.8

 

 

$

63.4

 

 

1.
Such amounts are based on benefit amounts and certain key assumptions obtained from the Salaried VEBA trustees and will be paid out of the Salaried VEBA plan assets. We have an ongoing obligation to make variable cash contributions to the Salaried VEBA, up to a maximum of $2.9 million annually based on our cash flow.
Summary of Asset Class Allocation per Pension Plan Investment Policy and Weighted Average Asset Allocation

Plan Assets. The fundamental goal underlying our pension plan investment policy is to ensure that the assets of the plans are invested in a prudent manner to earn a rate of return over time to meet the obligations of the plans as these obligations come due. Risk management practices include diversification across asset classes and periodic rebalancing toward established asset allocation targets. Our investment policy permits variances from the targets within certain parameters.

 

The following table presents the weighted-average target and actual asset class allocations for our pension plans:

 

Asset class

 

2024 Target allocation

 

As of December 31, 2024

Equities

 

56%

 

55%

Fixed income

 

38%

 

38%

Real estate investments

 

5%

 

6%

Cash and short-term investments

 

1%

 

1%
Schedule of Fair Value of Plan Assets

The following table presents the fair value of plan assets at December 31, 2024 and 2023, classified under the appropriate level of the fair value hierarchy (in millions of dollars):

 

 

 

December 31, 2024

 

 

December 31, 2023

 

 

Plan Assets in the Fair Value Hierarchy:

 

Level 1

 

 

Salaried VEBA – Equity investment funds in registered investment companies1

 

$

25.2

 

 

$

25.5

 

 

Salaried VEBA – Fixed income investment funds in registered investment companies2

 

 

16.8

 

 

 

16.5

 

 

Salaried VEBA – Cash and money market investments

 

 

0.2

 

 

 

—

 

 

Pension plans – Diversified investment funds in pooled separate accounts3

 

 

17.1

 

 

 

11.2

 

 

Pension plans – Diversified investment funds in registered investment companies4

 

 

5.4

 

 

 

9.3

 

 

Deferred compensation program – Diversified investment funds in registered investment companies4

 

 

11.9

 

 

 

11.1

 

 

Total plan assets in the fair value hierarchy

 

$

76.6

 

 

$

73.6

 

 

 

1.
Equity investment funds in registered investment companies. This category represents investments in equity funds.
2.
Fixed income investment funds in registered investment companies. This category represents investments in various fixed income funds with multiple registered investment companies. Such funds invest primarily in bonds, debentures, notes, securities with equity and fixed-income characteristics, cash equivalents, securities backed by mortgages and other assets, loans, pooled or collective investment vehicles made up of fixed‑income securities and other fixed-income obligations of banks, corporations, and governmental authorities.
3.
Diversified investment funds in pooled separate accounts. The plan assets are invested in various pooled separate accounts that hold a diversified portfolio of: (i) equity and equity-related securities of U.S. and non-U.S. issuers across all market capitalizations; (ii) fixed income securities such as corporate bonds and government bonds; and (iii) commercial real estate, including mortgage loans which are backed by the associated properties. The pooled separate accounts are valued daily based on the market value of the underlying net assets in each separate account. The majority of the underlying net assets have observable Level 1 pricing inputs which are used to determine the unit value of the pooled separate account which is not publicly quoted.
4.
Diversified investment funds in registered investment companies. The assets in the rabbi trust are invested in investment funds that hold a diversified portfolio of: (i) U.S. and international debt and equity securities; (ii) fixed income securities such as corporate bonds and government bonds; (iii) mortgage-related securities; and (iv) cash and cash equivalents.
Schedule of Total Expense Related to Benefit Plans

The following table presents the total expense related to all benefit plans (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Defined contribution plans1

 

$

18.6

 

 

$

18.1

 

 

$

17.1

 

Deferred compensation plan2

 

 

1.3

 

 

 

1.2

 

 

 

(0.6

)

Multiemployer pension plans1,3

 

 

6.1

 

 

 

5.6

 

 

 

5.2

 

Net periodic postretirement and postemployment benefit cost relating to defined benefit plans2,3,4

 

 

9.0

 

 

 

13.4

 

 

 

13.1

 

Total

 

$

35.0

 

 

$

38.3

 

 

$

34.8

 

 

1.
Substantially all of these charges related to employee benefits are in COGS with the remaining balance in SG&A and R&D within our Statements of Consolidated Income (Loss).
2.
Deferred compensation plan expense and the current service cost component of Net periodic postretirement and postemployment benefit cost relating to Salaried VEBA are included within our Statements of Consolidated Income (Loss) in SG&A and R&D for all periods presented. All other components of Net periodic postretirement and postemployment benefit cost relating to Salaried VEBA are included within Other income, net, in our Statements of Consolidated Income (Loss).
3.
See Note 6 for more information on our multiemployer defined benefit pension plans. For the year ended December 31, 2024, the expense presented excludes a $4.6 million charge to Restructuring costs (see Note 12).
4.
The current service cost component of Net periodic postretirement and postemployment benefit cost relating to both the pension plans and the OPEB plan is included within COGS in our Statements of Consolidated Income (Loss) for all periods presented. All other components of Net periodic postretirement and postemployment benefit cost relating to both the pension plans and the OPEB plan are included within Other income, net, in our Statements of Consolidated Income (Loss).
Schedule of Net Benefit Costs The following table presents the components of Net periodic postretirement and postemployment benefit cost relating to our defined benefit plans (in millions of dollars):

 

 

 

Pension Plans

 

 

OPEB

 

 

Salaried VEBA

 

 

 

Year Ended December 31,

 

 

Year Ended December 31,

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

 

2024

 

 

2023

 

 

2022

 

 

2024

 

 

2023

 

 

2022

 

Service cost

 

$

3.6

 

 

$

3.8

 

 

$

5.8

 

 

$

1.1

 

 

$

1.1

 

 

$

1.6

 

 

$

—

 

 

 

—

 

 

$

0.1

 

Interest cost

 

 

1.6

 

 

 

1.3

 

 

 

0.6

 

 

 

3.3

 

 

 

3.4

 

 

 

2.2

 

 

 

2.2

 

 

 

2.9

 

 

 

1.9

 

Expected return on plan assets

 

 

(1.4

)

 

 

(1.1

)

 

 

(0.9

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(2.2

)

 

 

(2.2

)

 

 

(3.1

)

Amortization of prior service cost1

 

 

0.8

 

 

 

0.4

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

1.7

 

 

 

4.9

 

 

 

4.9

 

Amortization of net actuarial gain

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(1.1

)

 

 

(1.1

)

 

 

—

 

 

 

(0.1

)

 

 

—

 

 

 

—

 

Settlement gain recognized

 

 

(0.5

)

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

Total net periodic postretirement and postemployment benefit cost

 

$

4.1

 

 

$

4.4

 

 

$

5.5

 

 

$

3.3

 

 

$

3.4

 

 

$

3.8

 

 

$

1.6

 

 

$

5.6

 

 

$

3.8

 

 

1.
We amortize prior service cost on a straight-line basis over the average remaining years of service of the active plan participants.
v3.25.0.1
Multiemployer Pension Plans (Tables)
 12 Months Ended
Dec. 31, 2024
Retirement Benefits [Abstract]  
Multiemployer Pension Plan Description and Contributions

The following table presents information about multiemployer pension plans in which we participate:

 

 

 

 

 

Pension

 

FIP/RP Status

 

Contributions of

 

 

 

 

 

 

 

 

 

Employer

 

Protection Act

 

Pending/

 

the Company

 

 

Surcharge

 

Expiration Date

 

 

Identification

 

Zone Status1

 

Implemented

 

Year Ended December 31,

 

 

Imposed

 

of Collective-

Pension Fund

 

Number

 

2024

 

2023

 

in 2024²

 

2024

 

 

2023

 

 

2022

 

 

in 2024

 

Bargaining Agreements

 

 

 

 

 

 

 

 

 

 

(in millions of dollars)

 

 

 

 

 

 

 

USW3

 

23-6648508

 

Green

 

Green

 

No

 

$

4.7

 

 

$

4.2

 

 

$

3.8

 

 

No

 

Sep 2025 - Nov 2026

Other Funds4

 

 

 

 

 

 

 

 

 

 

1.4

 

 

 

1.4

 

 

 

1.4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

$

6.1

 

 

$

5.6

 

 

$

5.2

 

 

 

 

 

 

 

 

1.
The zone status is based on information that we received from the plan and is certified by the plan’s actuary. Among other factors, plans in the green zone are at least 80% funded.
2.
The “FIP/RP Status Pending/Implemented” column indicates if a Financial Improvement Plan (“FIP”) or a Rehabilitation Plan (“RP”) is either pending or has been implemented for the plan under the Pension Protection Act.
3.
We are party to three collective bargaining agreements with the USW that require contributions to the Steelworkers Pension Trust (“SPT”). As of December 31, 2024, USW collective bargaining agreements covering employees at Newark and Trentwood covered
87% of our USW-represented employees with SPT benefits and expire in September 2025. See Note 18 for information related to the renewal of the collective bargaining agreements. Our monthly contributions per hour worked by each bargaining unit employee at Newark and Trentwood were (in whole dollars) $1.75 in the first half of 2024 and $2.06 in the second half of 2024. The union contracts covering employees at our Richmond, Virginia facility and Florence, Alabama facility cover 10% and 3%, respectively, of our USW-represented employees with SPT benefits and expire in November 2026 and March 2026, respectively. Our monthly contributions per hour worked by each bargaining unit employee at our Richmond, Virginia facility and Florence, Alabama facility were (in whole dollars) $1.50 and $1.35, respectively, in 2024.
4.
Other Funds consists of plans that are not individually significant.
v3.25.0.1
Employee Incentive Plans (Tables)
 12 Months Ended
Dec. 31, 2024
Summary of RSAs and RSUs Activity

The following table summarizes activity relating to RSAs and RSUs for the year ended December 31, 2024:

 

 

 

Shares
(in whole shares)

 

 

Weighted-
Average
Grant-Date
Fair Value
per Share
(in whole dollars)

 

Outstanding at December 31, 2023

 

 

399,387

 

 

$

80.41

 

Granted

 

 

132,490

 

 

 

64.84

 

Vested

 

 

(107,831

)

 

 

97.57

 

Forfeited

 

 

(15,372

)

 

 

70.99

 

Outstanding at December 31, 2024

 

 

408,674

 

 

$

71.19

 
Summary of Performance Shares Activity

The following table summarizes activity relating to performance shares for the year ended December 31, 2024:

 

 

 

Shares
(in whole shares)

 

 

Weighted-
Average
Grant-Date
Fair Value
per Share
(in whole dollars)

 

Outstanding at December 31, 2023

 

 

328,616

 

 

$

114.79

 

Granted 1

 

 

175,662

 

 

 

86.50

 

Forfeited 1

 

 

(7,060

)

 

 

94.84

 

Canceled 1

 

 

(100,212

)

 

 

137.07

 

Outstanding at December 31, 2024

 

 

397,006

 

 

$

97.00

 

 

1.
The number of shares granted and forfeited are presented at their maximum payout; and the number of shares canceled includes the number of shares that did not vest due to performance results falling below those required for maximum payout.
Summary of Non-Cash Compensation Expense under LTI Programs

Non-Cash Compensation Expense. Non-cash compensation expense is primarily included in SG&A and R&D. The following table presents non-cash compensation expense by type of award under LTI Programs (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

RSAs and RSUs

 

$

8.9

 

 

$

10.7

 

 

$

8.8

 

Performance shares

 

 

4.9

 

 

 

4.7

 

 

 

4.9

 

Total non-cash compensation expense

 

$

13.8

 

 

$

15.4

 

 

$

13.7

 
Summary of Unrecognized Gross Compensation Cost and Expected Period Over Which Remaining Gross Compensation Costs Will Be Recognized By Type of Award

Unrecognized Gross Compensation Cost Data. The following table presents unrecognized gross compensation costs and the expected period over which the remaining gross compensation costs will be recognized by type of award as of December 31, 2024:

 

 

 

Unrecognized Gross Compensation Costs
(in millions
of dollars)

 

 

Expected Period
(in years)
Over Which the Remaining Gross Compensation Costs Will Be Recognized

 

RSAs and RSUs

 

$

12.6

 

 

 

2.1

 

Performance shares

 

$

6.1

 

 

 

1.8

 
Summary of Weighted-Average Grant-Date Fair Value per Share for Shares Granted by Type of Award

The following table presents the weighted-average grant-date fair value per share for shares granted by type of award (in whole dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

RSAs and RSUs

 

$

64.84

 

 

$

71.81

 

 

$

84.16

 

Performance shares

 

$

86.50

 

 

$

96.65

 

 

$

111.37

 
Performance Shares  
Summary of Weighted Average Inputs and Assumptions Used to Calculate Fair Value at Grant Date

The following table presents the weighted average inputs and assumptions used in the Monte Carlo simulations to calculate the fair value at the grant date of our TSR-Based Performance Shares:

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Grant date fair value (in whole dollars)

 

$

96.34

 

 

$

104.87

 

 

$

122.22

 

Grant date stock price (in whole dollars)

 

$

71.76

 

 

$

84.33

 

 

$

95.13

 

Expected volatility of Kaiser Aluminum1

 

 

45.59

%

 

 

49.72

%

 

 

49.37

%

Expected volatility of peer companies1

 

 

38.67

%

 

 

45.14

%

 

 

51.08

%

Risk-free interest rate

 

 

4.31

%

 

 

4.59

%

 

 

1.59

%

Dividend yield

 

 

4.29

%

 

 

3.65

%

 

 

3.24

%

 

1.
Weighted average expected volatility based on 2.8 years of daily closing share prices from the valuation date to the end of the performance period.
v3.25.0.1
Derivatives, Hedging Programs and Other Financial Instruments (Tables)
 12 Months Ended
Dec. 31, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Summary of Derivative Positions

The following table summarizes our derivative positions at December 31, 2024:

 

Aluminum

 

Maturity Period

 

Notional Amount of Contracts (mmlbs)

 

Fixed price purchase contracts for LME

 

January 2025 through April 2026

 

 

57.8

 

Fixed price sale contracts for LME

 

January 2025

 

 

10.5

 

Fixed price purchase contracts for MWTP

 

January 2025 through April 2026

 

 

49.9

 

Fixed price sale contracts for MWTP

 

January 2025

 

 

10.5

 

 

 

Alloying Metals

 

Maturity Period

 

Notional Amount of Contracts (mmlbs)

 

Fixed price purchase contracts

 

January 2025 through December 2026

 

 

9.0

 

 

Natural Gas

 

Maturity Period

 

Notional Amount of Contracts (mmbtu)

 

Fixed price purchase contracts

 

January 2025 through December 2026

 

 

2,760,000

 

 

Euros

 

Maturity Period

 

Notional Amount of Contracts (EUR)

 

Fixed price forward purchase contracts

 

January 2025 through July 2027

 

 

7,236,092

 

 

British Pounds

 

Maturity Period

 

Notional Amount of Contracts (GBP)

 

Fixed price forward purchase contracts

 

January 2025 through February 2025

 

 

20,000

 
Summary of (Gain) Loss Associated with Derivative Contracts

The following table summarizes the amount of (gain) loss on derivative contracts recorded within our Statements of Consolidated Income (Loss) in COGS (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

2024

 

 

2023

 

 

2022

 

Total of income and expense line items presented in our Statements of Consolidated Income (Loss) in which the effects of hedges are recorded:

 

 

 

 

 

Cash flow hedges

 

$

2,691.1

 

 

$

2,754.9

 

 

$

3,180.2

 

 

 

 

 

 

 

 

 

 

(Gain) loss recognized in our Statements of Consolidated Income (Loss) related to cash flow hedges:

 

 

 

 

 

 

 

 

 

Aluminum

 

$

(1.4

)

 

$

12.8

 

 

$

7.4

 

Alloying Metals

 

 

(1.1

)

 

 

—

 

 

 

—

 

Natural gas

 

 

1.0

 

 

 

0.1

 

 

 

(6.6

)

Electricity

 

 

0.6

 

 

 

—

 

 

 

(11.3

)

Total (gain) loss recognized in our Statements of Consolidated Income (Loss) related to cash flow hedges

 

$

(0.9

)

 

$

12.9

 

 

$

(10.5

)

 

 

 

 

 

 

 

 

 

Loss (gain) recognized in our Statements of Consolidated Income (Loss) related to non-designated hedges:

 

 

 

 

 

 

 

 

 

Alloying Metals – Realized loss (gain)

 

$

—

 

 

$

0.1

 

 

$

(0.5

)

Alloying Metals – Unrealized mark-to-market loss

 

 

—

 

 

 

—

 

 

 

1.4

 

Electricity – Realized loss

 

 

5.0

 

 

 

—

 

 

 

—

 

Total loss recognized in our Statements of Consolidated Income (Loss) related to non-designated hedges

 

$

5.0

 

 

$

0.1

 

 

$

0.9

 

 
Schedule of Fair Value of Derivative Financial Instruments The following table presents the fair value of our derivative financial instruments (in millions of dollars):

 

 

 

As of December 31, 2024

 

 

As of December 31, 2023

 

 

 

Assets

 

 

Liabilities

 

 

Net Amount

 

 

Assets

 

 

Liabilities

 

 

Net Amount

 

Aluminum –

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fixed price purchase contracts for LME

 

$

1.1

 

 

$

(0.8

)

 

$

0.3

 

 

$

3.4

 

 

$

(0.6

)

 

$

2.8

 

Fixed price sale contracts for LME

 

 

—

 

 

 

—

 

 

 

—

 

 

 

—

 

 

 

(0.2

)

 

 

(0.2

)

Fixed price purchase contracts for MWTP

 

 

1.1

 

 

 

—

 

 

 

1.1

 

 

 

0.4

 

 

 

(0.3

)

 

 

0.1

 

Fixed price sale contracts for MWTP

 

 

—

 

 

 

—

 

 

 

—

 

 

 

0.1

 

 

 

(0.2

)

 

 

(0.1

)

Alloying Metals – Fixed price purchase contracts

 

 

1.3

 

 

 

(0.1

)

 

 

1.2

 

 

 

0.7

 

 

 

(0.1

)

 

 

0.6

 

Natural gas – Fixed price purchase contracts

 

 

0.5

 

 

 

(0.8

)

 

 

(0.3

)

 

 

0.3

 

 

 

(0.9

)

 

 

(0.6

)

Electricity – Fixed price purchase contracts

 

 

—

 

 

 

—

 

 

 

—

 

 

 

0.5

 

 

 

(0.6

)

 

 

(0.1

)

Foreign Currency – Fixed price forward contracts

 

 

—

 

 

 

(0.4

)

 

 

(0.4

)

 

 

0.5

 

 

 

—

 

 

 

0.5

 

Total

 

$

4.0

 

 

$

(2.1

)

 

$

1.9

 

 

$

5.9

 

 

$

(2.9

)

 

$

3.0

 

 

The following table presents the total amounts of derivative assets and liabilities on our Consolidated Balance Sheets (in millions of dollars):

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

Derivative assets:

 

 

 

 

 

 

Prepaid expenses and other current assets

 

$

3.7

 

 

$

4.8

 

Other assets

 

 

0.3

 

 

 

1.1

 

Total derivative assets

 

$

4.0

 

 

$

5.9

 

Derivative liabilities:

 

 

 

 

 

 

Other accrued liabilities

 

$

(1.8

)

 

$

(2.4

)

Long-term liabilities

 

 

(0.3

)

 

 

(0.5

)

Total derivative liabilities

 

$

(2.1

)

 

$

(2.9

)
v3.25.0.1
Debt and Credit Facility (Tables)
 12 Months Ended
Dec. 31, 2024
Debt Disclosure [Abstract]  
Summary of Senior Notes The following table summarizes key details of our outstanding Senior Notes:

 

 

 

 

 

 

 

 

Outstanding (in millions of dollars)

 

 

 

Issuance Date

 

Maturity

 

Effective Interest Rate

 

As of December 31, 2024

 

 

As of December 31, 2023

 

4.625% Senior Notes

 

November 2019

 

March 2028

 

4.8%

 

$

500.0

 

 

$

500.0

 

4.50% Senior Notes

 

May 2021

 

June 2031

 

4.7%

 

 

550.0

 

 

 

550.0

 

Total debt

 

 

 

 

 

 

 

 

1,050.0

 

 

 

1,050.0

 

Unamortized issuance costs

 

 

 

 

 

 

 

 

(8.4

)

 

 

(10.2

)

Total carrying amount

 

 

 

 

 

 

 

$

1,041.6

 

 

$

1,039.8

 
Summary of Fair Value of Outstanding Senior Notes

The following table presents the fair value of our outstanding Senior Notes, which are Level 1 liabilities (in millions of dollars):

 

 

 

 

 

 

 

As of December 31,

 

 

 

 

 

 

 

2024

 

 

2023

 

4.625% Senior Notes

 

 

 

 

 

$

470.1

 

 

$

462.4

 

4.50% Senior Notes

 

 

 

 

 

$

484.8

 

 

$

474.1

 
Schedule of Availability and Usage of Revolving Credit Facility

The following table summarizes availability and usage of our Revolving Credit Facility as determined by a borrowing base calculated as of December 31, 2024 (in millions of dollars):

 

Revolving Credit Facility borrowing commitment

 

$

575.0

 

Borrowing base availability

 

$

575.0

 

Less: Outstanding borrowings under Revolving Credit Facility

 

 

—

 

Less: Outstanding letters of credit under Revolving Credit Facility

 

 

(21.6

)

Remaining borrowing availability

 

$

553.4

 

 
Summary of Interest Expense Relating to Senior Notes and Revolving Credit Facility

The following table presents interest expense relating to our Senior Notes and Revolving Credit Facility (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Senior Notes interest expense, including debt issuance cost amortization

 

$

49.6

 

 

$

49.6

 

 

$

49.6

 

Revolving Credit Facility interest expense, including commitment fees and finance cost amortization

 

 

2.4

 

 

 

3.0

 

 

 

2.0

 

Interest expense on finance lease liabilities

 

 

0.8

 

 

 

0.7

 

 

 

0.3

 

Interest expense capitalized as construction in progress

 

 

(9.1

)

 

 

(6.4

)

 

 

(3.6

)

Total interest expense

 

$

43.7

 

 

$

46.9

 

 

$

48.3

 
Schedule of Future Principal Payments for Senior Notes and Revolving Credit Facility

The following table presents the future principal payments for our Senior Notes and Revolving Credit Facility as of December 31, 2024 (in millions of dollars):

 

Year ending December 31,

 

 

2025

$

—

 

2026

 

—

 

2027

 

—

 

2028

 

500.0

 

2029

 

—

 

Thereafter

 

550.0

 

Total

$

1,050.0

 
v3.25.0.1
Commitments and Contingencies (Tables)
 12 Months Ended
Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]  
Summary of Activities Relating to Company's CARO Liabilities

The following table summarizes activity relating to CARO liabilities (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Beginning balance

 

$

10.9

 

 

$

10.1

 

 

$

7.2

 

Liabilities added during the period

 

 

—

 

 

 

—

 

 

 

2.3

 

Liabilities settled during the period

 

 

(0.1

)

 

 

—

 

 

 

(0.1

)

Accretion expense

 

 

0.9

 

 

 

0.8

 

 

 

0.7

 

Ending balance

 

$

11.7

 

 

$

10.9

 

 

$

10.1

 
Schedule of Changes in Environmental Contingencies

The following table presents the changes in our environmental accrual. We classify the short-term and long-term liabilities within Other accrued liabilities and Long-term liabilities, respectively, on our Consolidated Balance Sheets (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Beginning balance

 

$

17.0

 

 

$

17.7

 

 

$

16.8

 

Additional accruals

 

 

4.2

 

 

 

1.2

 

 

 

3.2

 

Less: expenditures

 

 

(2.8

)

 

 

(1.9

)

 

 

(2.3

)

Ending balance

 

$

18.4

 

 

$

17.0

 

 

$

17.7

 
v3.25.0.1
Accumulated Other Comprehensive Income (Tables)
 12 Months Ended
Dec. 31, 2024
Equity [Abstract]  
Schedule of Accumulated Other Comprehensive Income

The following table presents the changes in the accumulated balances for each component of AOCI (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Defined Benefit Plans:

 

 

 

 

 

 

 

 

 

Beginning balance

 

$

11.0

 

 

$

2.8

 

 

$

(21.4

)

Actuarial gain arising during the period

 

 

12.2

 

 

 

4.3

 

 

 

27.0

 

Less: income tax expense

 

 

(2.8

)

 

 

(1.0

)

 

 

(6.5

)

Net actuarial gain arising during the period

 

 

9.4

 

 

 

3.3

 

 

 

20.5

 

Prior service (cost) credit arising during the period

 

 

(2.2

)

 

 

2.2

 

 

 

—

 

Less: income tax benefit (expense)

 

 

0.5

 

 

 

(0.5

)

 

 

—

 

Net prior service (cost) credit arising during the period

 

 

(1.7

)

 

 

1.7

 

 

 

—

 

Amortization of net actuarial gain1,2

 

 

(2.0

)

 

 

(1.1

)

 

 

—

 

Amortization of prior service cost1

 

 

2.5

 

 

 

5.3

 

 

 

4.9

 

Less: income tax expense3

 

 

(0.1

)

 

 

(1.0

)

 

 

(1.2

)

Net amortization reclassified from AOCI to Net income (loss)

 

 

0.4

 

 

 

3.2

 

 

 

3.7

 

Other comprehensive income, net of tax

 

 

8.1

 

 

 

8.2

 

 

 

24.2

 

Ending balance

 

$

19.1

 

 

$

11.0

 

 

$

2.8

 

 

 

 

 

 

 

 

 

 

Cash Flow Hedges:

 

 

 

 

 

 

 

 

 

Beginning balance

 

$

2.1

 

 

$

0.4

 

 

$

17.7

 

Unrealized loss on cash flow hedges

 

 

(0.2

)

 

 

(10.7

)

 

 

(12.2

)

Less: income tax benefit

 

 

—

 

 

 

2.5

 

 

 

2.9

 

Net unrealized loss on cash flow hedges

 

 

(0.2

)

 

 

(8.2

)

 

 

(9.3

)

Reclassification of unrealized (gain) loss upon settlement
   of cash flow hedges

 

 

(0.9

)

 

 

12.9

 

 

 

(10.5

)

Reclassification due to forecasted transactions probable of not
   occurring

 

 

0.2

 

 

 

—

 

 

 

—

 

Less: income tax benefit (expense)3

 

 

0.2

 

 

 

(3.0

)

 

 

2.5

 

Net (gain) loss reclassified from AOCI to Net income (loss)

 

 

(0.5

)

 

 

9.9

 

 

 

(8.0

)

Other comprehensive (loss) income, net of tax

 

 

(0.7

)

 

 

1.7

 

 

 

(17.3

)

Ending balance4

 

$

1.4

 

 

$

2.1

 

 

$

0.4

 

 

 

 

 

 

 

 

 

 

Total AOCI ending balance

 

$

20.5

 

 

$

13.1

 

 

$

3.2

 

 

1.
Amounts amortized out of AOCI related to pension and other postretirement and postemployment benefits were included within Net periodic postretirement and postemployment benefit cost (see Note 5).
2.
Amounts amortized out of AOCI during the year ended December 31, 2024 include net actuarial gains recognized on a pro-rata basis in conjunction with a group annuity purchase (see Note 5).
3.
Income tax amounts reclassified out of AOCI were included as a component of Income tax (provision) benefit.
4.
As of December 31, 2024, we estimate a net mark-to-market gain before tax of $1.9 million in AOCI will be reclassified into Net income (loss) upon settlement within the next 12 months.
v3.25.0.1
Restructuring (Tables)
 12 Months Ended
Dec. 31, 2024
2024 Plan  
Restructuring Cost and Reserve [Line Items]  
Summary of Activity Relating to Restructuring Plan Liabilities

The following table summarizes activity relating to the 2024 Restructuring Plan liabilities (in millions of dollars):

BALANCE, December 31, 2023

 

$

—

 

Restructuring costs

 

 

7.5

 

Costs paid or otherwise settled1

 

 

(2.8

)

BALANCE, December 31, 2024

 

$

4.7

 
1.
Cash paid during the year ended December 31, 2024 was $2.6 million.
2022 Plan  
Restructuring Cost and Reserve [Line Items]  
Summary of Activity Relating to Restructuring Plan Liabilities

The following table summarizes activity relating to the 2022 Restructuring Plan liabilities (in millions of dollars):

BALANCE, December 31, 2021

 

$

—

 

Restructuring costs

 

 

2.2

 

Costs paid or otherwise settled1

 

 

(0.5

)

BALANCE, December 31, 2022

 

 

1.7

 

Restructuring costs

 

 

5.0

 

Costs paid or otherwise settled1

 

 

(5.5

)

BALANCE, December 31, 2023

 

 

1.2

 

Restructuring costs

 

 

0.1

 

Costs paid or otherwise settled1

 

 

(1.3

)

BALANCE, December 31, 2024

 

$

—

 

 

1.
Cash paid during the years ended December 31, 2024, December 31, 2023, and December 31, 2022 was $1.2 million, $5.0 million, and $0.4 million respectively.
v3.25.0.1
Other Income, Net (Tables)
 12 Months Ended
Dec. 31, 2024
Other Income and Expenses [Abstract]  
Other Income, Net

The following table presents the components of Other income, net, (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Interest income

 

$

3.6

 

 

$

1.7

 

 

$

1.3

 

Net periodic postretirement and postemployment benefit cost

 

 

(4.3

)

 

 

(8.4

)

 

 

(5.6

)

Unrealized gain (loss) on equity securities

 

 

0.3

 

 

 

0.6

 

 

 

(1.2

)

Gain on disposition of property, plant and equipment

 

 

3.8

 

 

 

13.8

 

 

 

6.0

 

Gain on business interruption insurance recoveries1

 

 

16.3

 

 

 

—

 

 

 

—

 

Post-acquisition funding received from Alcoa Corporation2

 

 

—

 

 

 

—

 

 

 

6.0

 

All other, net

 

 

(0.2

)

 

 

(0.3

)

 

 

(0.1

)

Other income, net

 

$

19.5

 

 

$

7.4

 

 

$

6.4

 

 

1.
Represents advances against business interruption insurance claims. We recognize such advances in the period in which the insurance proceeds are received or become realizable. As of December 31, 2024 we received net cash proceeds of $15.9 million.
2.
Represents reimbursement received for repairs and maintenance expenditures on certain machinery and equipment that we had purchased from Alcoa in connection with our March 31, 2021 acquisition of Warrick.
v3.25.0.1
Income Tax Matters (Tables)
 12 Months Ended
Dec. 31, 2024
Income Tax Disclosure [Abstract]  
Income (Loss) Before Income Taxes by Geographic Area

The following table presents Income (loss) before income taxes by geographic area (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Domestic

 

$

53.5

 

 

$

48.0

 

 

$

(44.6

)

Foreign

 

 

10.0

 

 

 

8.3

 

 

 

6.7

 

Income (loss) before income taxes

 

$

63.5

 

 

$

56.3

 

 

$

(37.9

)
Income Tax (Provision) Benefit

The following table presents the components of Income tax (provision) benefit (in millions of dollars):

 

 

 

Federal

 

 

Foreign

 

 

State

 

 

Total

 

Year Ended December 31, 2024

 

 

 

 

 

 

 

 

 

 

 

 

Current

 

$

(3.5

)

 

$

(3.1

)

 

$

(3.3

)

 

$

(9.9

)

Deferred

 

 

(10.9

)

 

 

0.6

 

 

 

1.3

 

 

$

(9.0

)

Benefit applied to decrease AOCI

 

 

1.9

 

 

 

—

 

 

 

0.3

 

 

$

2.2

 

Income tax (provision) benefit

 

$

(12.5

)

 

$

(2.5

)

 

$

(1.7

)

 

$

(16.7

)

Year Ended December 31, 2023

 

 

 

 

 

 

 

 

 

 

 

 

Current

 

$

—

 

 

$

(2.2

)

 

$

0.6

 

 

$

(1.6

)

Deferred

 

 

(11.6

)

 

 

0.1

 

 

 

1.0

 

 

 

(10.5

)

Benefit applied to decrease AOCI

 

 

2.5

 

 

 

0.1

 

 

 

0.4

 

 

 

3.0

 

Income tax (provision) benefit

 

$

(9.1

)

 

$

(2.0

)

 

$

2.0

 

 

$

(9.1

)

Year Ended December 31, 2022

 

 

 

 

 

 

 

 

 

 

 

 

Current

 

$

—

 

 

$

(1.1

)

 

$

(2.5

)

 

$

(3.6

)

Deferred

 

 

8.9

 

 

 

(0.8

)

 

 

1.6

 

 

 

9.7

 

Benefit applied to decrease AOCI

 

 

1.7

 

 

 

0.2

 

 

 

0.3

 

 

 

2.2

 

Income tax benefit (provision)

 

$

10.6

 

 

$

(1.7

)

 

$

(0.6

)

 

$

8.3

 
Reconciliation of Income Tax (Provision) Benefit based on Effective Income Tax Rate and Statutory Tax Rate

The following table presents a reconciliation between the (provision) benefit for income taxes and the amount computed by applying the federal statutory income tax rate to Income (loss) before income taxes (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Amount of federal income tax (provision) benefit based on the statutory rate

 

$

(13.3

)

 

$

(11.8

)

 

$

8.0

 

Decrease in federal valuation allowances

 

 

—

 

 

 

—

 

 

 

1.1

 

Non-deductible compensation expense

 

 

(2.2

)

 

 

(1.6

)

 

 

(0.9

)

Non-deductible (expense) benefit

 

 

(0.2

)

 

 

0.2

 

 

 

(1.0

)

State income tax (provision) benefit, net of federal benefit1

 

 

(1.4

)

 

 

1.5

 

 

 

(0.5

)

Research and development credit

 

 

1.2

 

 

 

3.2

 

 

 

2.2

 

Foreign income tax expense

 

 

(0.4

)

 

 

(0.3

)

 

 

(0.3

)

Foreign undistributed earnings

 

 

(0.4

)

 

 

(0.3

)

 

 

(0.3

)

Income tax (provision) benefit

 

$

(16.7

)

 

$

(9.1

)

 

$

8.3

 

 

1.
The total state income tax (provision) benefit, net of federal benefit was ($1.4) million in 2024, which was primarily a result of: (i) a current state income tax provision of ($1.5) million in 2024; (ii) a benefit of $2.9 million due to state NOL, return to provision and tax rate true-ups in various states, partially offset by (iii) an increase to the provision for a state tax valuation allowance of ($2.8) million related to the expiration of certain state net operating losses and credits. The total state income tax (provision) benefit, net of federal benefit was $1.5 million in 2023, which was primarily a result of: (i) a current state income tax provision of ($1.4) million in
2023; (ii) a benefit of $1.9 million due to state NOL and tax rate true-ups in various states; and (iii) a benefit of $1.0 million for a decrease to the state tax valuation allowance related to certain state net operating losses. The total state income tax (provision) benefit, net of federal benefit was ($0.5) million in 2022, which was primarily a result of: (i) a current state income tax benefit of $1.1 million in 2022; (ii) an increase of ($1.5) million to the provision due to state NOL and tax rate true-ups in various states; and (iii) an increase to the provision of ($0.1) million for an increase to the state tax valuation allowance related to the expiration of certain state net operating losses.
Deferred Tax Assets and Liabilities The following table presents the components of our net deferred income tax assets and liabilities (in millions of dollars):

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

Deferred income tax assets:

 

 

 

 

 

 

Loss and credit carryforwards

 

$

17.3

 

 

$

39.6

 

Defined benefit plans

 

 

3.1

 

 

 

3.6

 

Other assets

 

 

35.8

 

 

 

36.8

 

Lease assets

 

 

7.2

 

 

 

8.7

 

Inventories

 

 

39.8

 

 

 

29.5

 

Excess interest carryforward

 

 

10.2

 

 

 

14.0

 

Research & development capitalization

 

 

19.1

 

 

 

16.9

 

Valuation allowances

 

 

(5.5

)

 

 

(2.7

)

Total deferred income tax assets

 

 

127.0

 

 

 

146.4

 

Deferred income tax liabilities:

 

 

 

 

 

 

Property, plant and equipment

 

 

(133.3

)

 

 

(142.6

)

Lease liabilities

 

 

(7.2

)

 

 

(8.7

)

Undistributed foreign earnings

 

 

(3.4

)

 

 

(3.0

)

Total deferred income tax liabilities

 

 

(143.9

)

 

 

(154.3

)

Net deferred income tax liabilities

 

$

(16.9

)

 

$

(7.9

)
Reconciliation of Changes in Gross Unrecognized Tax Benefits

We have gross unrecognized benefits relating to uncertain tax positions. The following table presents a reconciliation of changes in the gross unrecognized tax benefits (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Gross unrecognized tax benefits at beginning of period

 

$

6.5

 

 

$

5.0

 

 

$

4.1

 

Gross increases for tax positions of current year

 

 

0.5

 

 

 

1.3

 

 

 

0.9

 

Gross increases for tax positions of prior years

 

 

—

 

 

 

0.2

 

 

 

0.1

 

Gross decreases for tax positions of prior years

 

 

(0.1

)

 

 

—

 

 

 

(0.1

)

Gross unrecognized tax benefits at end of period

 

$

6.9

 

 

$

6.5

 

 

$

5.0

 
v3.25.0.1
Net Income (Loss) Per Share (Tables)
 12 Months Ended
Dec. 31, 2024
Earnings Per Share [Abstract]  
Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share

The following table sets forth the computation of basic and diluted net income (loss) per share (in millions of dollars, except share and per share amounts):

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Numerator:

 

 

 

 

 

 

 

 

 

Net income (loss)

 

 

46.8

 

 

 

47.2

 

 

 

(29.6

)

Less: earnings attributable to participating securities1

 

 

—

 

 

 

(0.1

)

 

 

—

 

Net income (loss) available to common shareholders

 

 

46.8

 

 

 

47.1

 

 

 

(29.6

)

Denominator – Weighted-average common shares
   outstanding (in thousands):

 

 

 

 

 

 

 

 

 

Basic

 

 

16,069

 

 

 

15,991

 

 

 

15,906

 

Add: dilutive effect of non-vested common shares,
   restricted stock units and performance shares2

 

 

250

 

 

 

140

 

 

 

—

 

Diluted

 

 

16,319

 

 

 

16,131

 

 

 

15,906

 

 

 

 

 

 

 

 

 

 

Net income (loss) per common share, Basic

 

$

2.91

 

 

$

2.95

 

 

$

(1.86

)

Net income (loss) per common share, Diluted

 

$

2.87

 

 

$

2.92

 

 

$

(1.86

)
1.
Represents distributed and undistributed earnings allocated to non-vested RSAs that contain non-forfeitable rights to dividends.
2.
Quantities in the following discussion are denoted in whole shares. For the years ended December 31, 2024 and December 31, 2023, approximately 1,100 and 35,000 shares, respectively, were excluded from the weighted-average diluted shares computation as their inclusion would have been anti-dilutive. For the year ended December 31, 2022, approximately 139,000 potentially dilutive shares were excluded from the computation of net loss per share as their effect would have been anti‑dilutive.
v3.25.0.1
Supplemental Cash Flow Information (Tables)
 12 Months Ended
Dec. 31, 2024
Supplemental Cash Flow Elements [Abstract]  
Schedule of Supplemental Cash Flow Information

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

 

 

(in millions of dollars)

 

Interest paid

 

$

40.5

 

 

$

43.8

 

 

$

45.7

 

Non-cash investing and financing activities (included in Accounts payable):

 

 

 

 

 

 

 

 

 

Unpaid purchases of property and equipment

 

$

19.6

 

 

$

19.3

 

 

$

28.9

 

 

 

 

 

 

 

 

 

 

Supplemental lease disclosures:

 

 

 

 

 

 

 

 

 

Operating lease liabilities arising from obtaining operating lease assets

 

$

2.6

 

 

$

3.2

 

 

$

3.1

 

Cash paid for amounts included in the measurement of
   operating lease liabilities

 

$

8.2

 

 

$

9.3

 

 

$

9.8

 

Finance lease liabilities arising from obtaining finance lease assets

 

$

2.9

 

 

$

10.0

 

 

$

1.0

 

 

 

 

 

 

 

 

 

 

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

 

 

(in millions of dollars)

 

Components of cash, cash equivalents and restricted cash:

 

 

 

 

 

 

 

 

 

Cash and cash equivalents

 

$

18.4

 

 

$

82.4

 

 

$

57.4

 

Restricted cash included in Other assets

 

 

19.5

 

 

 

18.3

 

 

 

13.9

 

Total cash, cash equivalents and restricted cash presented on our Statements of
   Consolidated Cash Flows

 

$

37.9

 

 

$

100.7

 

 

$

71.3

 
v3.25.0.1
Business, Product and Geographical Area Information and Concentration of Risk (Tables)
 12 Months Ended
Dec. 31, 2024
Segment Reporting [Abstract]  
Schedule of Significant Segment Expenses Provided to CODM

The following table provides the significant segment expenses that are provided to the CODM (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Net sales

 

$

3,024.0

 

 

$

3,087.0

 

 

$

3,427.9

 

 

 

 

 

 

 

 

 

 

Less:

 

 

 

 

 

 

 

 

 

Cost of products sold, excluding depreciation and amortization

 

 

 

 

 

 

 

 

 

Hedged cost of alloyed metal1

 

 

1,567.8

 

 

 

1,621.1

 

 

 

2,045.2

 

Manufacturing costs2

 

 

805.2

 

 

 

809.9

 

 

 

773.0

 

Plant overhead3

 

 

170.5

 

 

 

164.6

 

 

 

162.3

 

Freight costs

 

 

91.6

 

 

 

103.3

 

 

 

125.5

 

Other cost of products sold4

 

 

56.0

 

 

 

56.0

 

 

 

74.2

 

Depreciation and amortization

 

 

116.4

 

 

 

108.6

 

 

 

106.9

 

Selling, general, administrative, research and development

 

 

 

 

 

 

 

 

 

Research and development costs

 

 

2.2

 

 

 

2.9

 

 

 

1.9

 

Employee costs5

 

 

83.3

 

 

 

80.0

 

 

 

69.9

 

Other selling, general and administrative costs6

 

 

35.3

 

 

 

39.8

 

 

 

39.1

 

Goodwill impairment

 

 

—

 

 

 

—

 

 

 

20.5

 

Restructuring costs

 

 

7.6

 

 

 

5.0

 

 

 

2.2

 

Other operating charges, net

 

 

0.4

 

 

 

—

 

 

 

3.2

 

Interest expense

 

 

43.7

 

 

 

46.9

 

 

 

48.3

 

Other income, net – Note 13

 

 

(19.5

)

 

 

(7.4

)

 

 

(6.4

)

Income tax provision (benefit)

 

 

16.7

 

 

 

9.1

 

 

 

(8.3

)

Net income (loss)

 

$

46.8

 

 

$

47.2

 

 

$

(29.6

)
1.
Hedged cost of alloyed metal includes cost of aluminum at the Midwest transaction price and the cost of alloying elements used in the production process. This metric also includes metal price exposure on shipments that we hedged with realized losses upon settlement of $0.2 million, $21.4 million, and $17.0 million in 2024, 2023, and 2022, respectively.
2.
Manufacturing costs primarily includes labor, utilities, supplies and other materials, excluding alloys incurred at our various production facilities.
3.
Plant overhead includes salaried employee costs, property taxes, and insurance associated with our various production facilities.
4.
Other costs of products sold primarily includes lease expense, accretion expense related to CAROs, and major maintenance costs.
5.
Employee costs include salaries, benefits, and incentive compensation.
6.
Other selling, general and administrative costs primarily includes professional services, computer hardware and software costs, office rent, and utilities.
Schedule of Net Sales by End Market Segment Applications

The following table presents Net sales by end market applications and by timing of control transfer (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Net sales:

 

 

 

 

 

 

 

 

 

Aero/HS Products

 

$

883.0

 

 

$

899.3

 

 

$

676.1

 

Packaging

 

 

1,260.9

 

 

 

1,315.2

 

 

 

1,585.3

 

GE Products

 

 

618.1

 

 

 

596.5

 

 

 

883.8

 

Automotive Extrusions

 

 

251.9

 

 

 

254.9

 

 

 

254.8

 

Other products

 

 

10.1

 

 

 

21.1

 

 

 

27.9

 

Total net sales

 

$

3,024.0

 

 

$

3,087.0

 

 

$

3,427.9

 

 

 

 

 

 

 

 

 

 

Timing of revenue recognition:

 

 

 

 

 

 

 

 

 

Products transferred at a point in time

 

$

2,326.5

 

 

$

2,394.8

 

 

$

2,782.9

 

Products transferred over time

 

 

697.5

 

 

 

692.2

 

 

 

645.0

 

Total net sales

 

$

3,024.0

 

 

$

3,087.0

 

 

$

3,427.9

 
Schedule of Net Sales, Income Taxes Paid, and Long-lived Assets, by Geographical Area

The following table presents geographic information for net sales based on country of origin, income taxes paid, and long-lived assets (in millions of dollars):

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Net sales to unaffiliated customers:

 

 

 

 

 

 

 

 

 

Domestic

 

$

2,920.0

 

 

$

2,986.0

 

 

$

3,328.2

 

Foreign1

 

 

104.0

 

 

 

101.0

 

 

 

99.7

 

Total net sales

 

$

3,024.0

 

 

$

3,087.0

 

 

$

3,427.9

 

Income taxes paid:

 

 

 

 

 

 

 

 

 

Domestic

 

$

1.3

 

 

$

0.3

 

 

$

3.1

 

Foreign

 

 

3.1

 

 

 

0.2

 

 

 

3.2

 

Total income taxes paid

 

$

4.4

 

 

$

0.5

 

 

$

6.3

 

 

 

 

As of December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Long-lived assets:2

 

 

 

 

 

 

 

 

 

Domestic

 

$

1,134.5

 

 

$

1,025.3

 

 

$

984.8

 

Foreign1

 

 

26.7

 

 

 

26.8

 

 

 

28.4

 

Total long-lived assets

 

$

1,161.2

 

 

$

1,052.1

 

 

$

1,013.2

 

 

1.
Foreign reflects our London, Ontario production facility.
2.
Long-lived assets represent Property, plant and equipment, net.
Schedule of Export Sales and Primary Aluminum Supply from Major Suppliers

The following table presents information about export sales and primary aluminum supply from our major suppliers:

 

 

 

Year Ended December 31,

 

 

 

2024

 

 

2023

 

 

2022

 

Percentage of Net sales:

 

 

 

 

 

 

 

 

 

Export sales

 

 

10

%

 

 

10

%

 

 

10

%

 

 

 

 

 

 

 

 

 

Percentage of total annual primary aluminum supply (lbs):

 

 

 

 

 

 

 

 

 

Supply from our top five major suppliers

 

 

80

%

 

 

83

%

 

 

81

%

Supply from our largest supplier

 

 

21

%

 

 

37

%

 

 

48

%

Supply from our second and third largest suppliers combined

 

 

38

%

 

 

28

%

 

 

20

%
v3.25.0.1
Summary of Significant Accounting Policies - Additional Information (Details)
 12 Months Ended
Dec. 31, 2024
USD ($)
Segment
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Significant Accounting Policies [Line Items]      
Number of operating segments | Segment 1    
Excess of current cost over the stated LIFO value of inventory $ 96,800,000 $ 56,000,000  
Impairment charge on land held for sale $ 400,000 0 $ 0
Lease, practical expedients, package [true false] true    
Accrued employee healthcare benefits $ 7,800,000 7,700,000  
Advertising costs 400,000 100,000 0
Research and development costs $ 12,000,000.0 $ 11,100,000 $ 9,300,000
Change in accounting principle, accounting standards update, adopted true    
Change in accounting principle, accounting standards update, immaterial effect true    
Accounting Standards Update [Extensible Enumeration] us-gaap:AccountingStandardsUpdate202307Member    
IN EDGE Tax Credit      
Significant Accounting Policies [Line Items]      
Government grants eligible conditions description (i) minimum cumulative expenditures towards capital expenditures and (ii) a minimum number of full-time employees.    
Minimum      
Significant Accounting Policies [Line Items]      
Period over which accounts receivable is due, days 30 days    
Maximum      
Significant Accounting Policies [Line Items]      
Period over which accounts receivable is due, days 90 days    
v3.25.0.1
Summary of Significant Accounting Policies - Schedule of Total Government Assistance Recognized (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2024
USD ($)
Government Grant  
Significant Accounting Policies [Line Items]  
Government assistance recognized amount $ 1.6
IN EDGE Tax Credit | Indiana Economic Development Corporation | Cost of Products Sold  
Significant Accounting Policies [Line Items]  
Government assistance recognized amount $ 1.6
IN EDGE Tax Credit | Indiana Economic Development Corporation | Cost of Products Sold | Minimum  
Significant Accounting Policies [Line Items]  
Government grants transaction duration 2021
IN EDGE Tax Credit | Indiana Economic Development Corporation | Cost of Products Sold | Maximum  
Significant Accounting Policies [Line Items]  
Government grants transaction duration 2030
v3.25.0.1
Summary of Significant Accounting Policies - Estimated Useful Lives of Property, Plant and Equipment (Details)
Dec. 31, 2024
Land Improvements | Minimum  
Property, Plant and Equipment  
Property, plant and equipment useful lives (in years) 1 year
Land Improvements | Maximum  
Property, Plant and Equipment  
Property, plant and equipment useful lives (in years) 25 years
Buildings and Leasehold Improvements | Minimum  
Property, Plant and Equipment  
Property, plant and equipment useful lives (in years) 2 years
Buildings and Leasehold Improvements | Maximum  
Property, Plant and Equipment  
Property, plant and equipment useful lives (in years) 45 years
Machinery and Equipment | Minimum  
Property, Plant and Equipment  
Property, plant and equipment useful lives (in years) 1 year
Machinery and Equipment | Maximum  
Property, Plant and Equipment  
Property, plant and equipment useful lives (in years) 22 years
Depreciable Finance Lease Assets | Minimum  
Property, Plant and Equipment  
Property, plant and equipment useful lives (in years) 2 years
Depreciable Finance Lease Assets | Maximum  
Property, Plant and Equipment  
Property, plant and equipment useful lives (in years) 120 years
v3.25.0.1
Supplemental Balance Sheet Information - Schedule of Supplemental Balance Sheet Information (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Trade Receivables, Net      
Allowance for doubtful receivables $ (0.8) $ (0.6)  
Trade receivables, net 319.7 325.2  
Inventories      
Finished products 103.7 89.3  
Work-in-process 193.3 210.8  
Raw materials 192.8 161.5  
Operating supplies 14.1 15.6  
Inventories 503.9 477.2  
Property, Plant and Equipment, Net      
Land and improvements 37.2 38.0  
Buildings and leasehold improvements 256.3 238.4  
Machinery and equipment [1] 1,337.4 1,265.3  
Construction in progress 297.5 173.7  
Property, plant and equipment, gross 1,928.4 1,715.4  
Accumulated depreciation and amortization (767.5) (663.7)  
Land held for sale 0.3 0.4  
Property, plant and equipment, net 1,161.2 1,052.1  
Other Assets      
Assets to be conveyed associated with Warrick acquisition [1] 18.3 56.8  
Restricted cash - Note 16 19.5 18.3 $ 13.9
Long-term replacement parts 18.3 16.7  
Other 22.5 25.9  
Other assets 78.6 117.7  
Other Accrued Liabilities      
Uncleared cash disbursements 24.5 15.7  
Accrued income taxes and other taxes payable 11.2 9.5  
Accrued annual contribution to Salaried VEBA - Note 5 0.7 1.1  
Accrued interest 9.9 9.9  
Short-term environmental accrual - Note 10 0.7 2.8  
Current operating lease liabilities - Note 3 6.3 8.0  
Current finance lease liabilities - Note 3 2.4 2.1  
Current deferred compensation plan liabilities - Note 5 6.7 0.4  
Other - Note 8 17.0 14.8  
Other accrued liabilities 79.4 64.3  
Long-Term Liabilities      
Workers' compensation accrual 26.8 29.9  
Long-term environmental accrual - Note 10 17.7 14.2  
Other long-term liabilities 39.5 37.6  
Long-term liabilities 84.0 81.7  
Billed      
Trade Receivables, Net      
Billed trade receivables $ 320.5 $ 325.8  
[1] During the year ended December 31, 2024, $38.5 million of certain assets associated with our acquisition of Warrick were conveyed to us and placed in service. At December 31, 2024, such assets are presented within Machinery and equipment.
v3.25.0.1
Supplemental Balance Sheet Information - Schedule of Supplemental Balance Sheet Information (Parenthetical) (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Assets to be conveyed associated with Warrick acquisition [1] $ 18.3 $ 56.8
Machinery and Equipment    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Assets to be conveyed associated with Warrick acquisition $ 38.5  
[1] During the year ended December 31, 2024, $38.5 million of certain assets associated with our acquisition of Warrick were conveyed to us and placed in service. At December 31, 2024, such assets are presented within Machinery and equipment.
v3.25.0.1
Leases - Schedule of Lease Terms and Discount Rates (Details)
Dec. 31, 2024
Dec. 31, 2023
Leases [Abstract]    
Finance Lease, Weighted Average Remaining Lease Term 36 years 10 months 24 days 38 years 9 months 18 days
Operating Lease, Weighted Average Remaining Lease Term 8 years 10 months 24 days 8 years 10 months 24 days
Finance Lease, Weighted Average Discount Rate, Percent 5.40% 5.31%
Operating Lease, Weighted Average Discount Rate, Percent 4.69% 4.35%
v3.25.0.1
Leases - Schedule of Lease Assets and Lease Liabilities (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Leases [Abstract]    
Operating lease assets $ 27.2 $ 32.6
Finance lease assets $ 14.8 $ 14.3
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Property, plant and equipment, net Property, plant and equipment, net
Current operating lease liabilities $ 6.3 $ 8.0
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other Accrued Liabilities, Current Other Accrued Liabilities, Current
Non-current operating lease liabilities $ 25.2 $ 29.2
Total operating lease liabilities 31.5 37.2
Current finance lease liabilities $ 2.4 $ 2.1
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other Accrued Liabilities, Current Other Accrued Liabilities, Current
Non-current finance lease liabilities $ 13.0 $ 12.9
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Other Liabilities, Noncurrent Other Liabilities, Noncurrent
Total finance lease liabilities $ 15.4 $ 15.0
v3.25.0.1
Leases - Components of Lease Cost (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Leases [Abstract]      
Operating lease cost $ 10.2 $ 11.6 $ 12.1
Short-term lease cost 4.0 4.3 4.3
Amortization of leased assets 2.4 2.4 2.5
Interest on lease liabilities 0.8 0.7 0.3
Total lease cost $ 17.4 $ 19.0 $ 19.2
v3.25.0.1
Leases - Schedule of Maturity of Our Lease Liabilities (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Operating Leases    
2025 $ 7.6  
2026 5.1  
2027 4.2  
2028 3.8  
2029 3.7  
Thereafter 15.6  
Total minimum lease payments 40.0  
Less: interest (8.5)  
Present value 31.5 $ 37.2
Finance Leases    
2025 3.1  
2026 2.5  
2027 1.5  
2028 1.0  
2029 0.7  
Thereafter 26.3  
Total minimum lease payments 35.1  
Less: interest (19.7)  
Present value $ 15.4 $ 15.0
v3.25.0.1
Goodwill and Intangible Assets - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Finite Lived Intangible Assets [Line Items]      
Goodwill impairment $ 0 $ 0 $ 20,500,000
Impairment of intangible assets     $ 3,100,000
Impairment, Intangible Asset, Finite-Lived, Statement of Income or Comprehensive Income [Extensible Enumeration]     Other Operating Income (Expense), Net
Impairment associated with intangible assets 0 0  
Amortization of definite-lived intangible assets $ 4,500,000 $ 5,300,000 $ 9,300,000
v3.25.0.1
Goodwill and Intangible Assets - Schedule of Goodwill (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Goodwill [Roll Forward]    
Gross carrying value $ 57.7 $ 57.7
Accumulated impairment loss (38.9) (38.9)
Net carrying value $ 18.8 $ 18.8
v3.25.0.1
Goodwill and Intangible Assets - Schedule of Goodwill (Parenthetical) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Goodwill [Line Items]    
Goodwill $ 18.8 $ 18.8
Impairment charge 38.9 $ 38.9
IMT    
Goodwill [Line Items]    
Goodwill, acquired 25.2  
Impairment charge $ 25.2  
v3.25.0.1
Goodwill and Intangible Assets - Schedule of Gross Carrying Amount and Accumulated Amortization By Major Intangible Asset Class (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Finite Lived Intangible Assets [Line Items]    
Weighted- Average Amortization Period (in years) 26 years 26 years
Gross Amount $ 82.9 $ 82.9
Accumulated Amortization (37.4) (32.9)
Intangible Assets, Net $ 45.5 $ 50.0
Customer relationships    
Finite Lived Intangible Assets [Line Items]    
Weighted- Average Amortization Period (in years) 19 years 19 years
Gross Amount $ 68.1 $ 68.1
Accumulated Amortization (30.3) (26.1)
Intangible Assets, Net $ 37.8 $ 42.0
Trade Name    
Finite Lived Intangible Assets [Line Items]    
Weighted- Average Amortization Period (in years) 10 years 10 years
Gross Amount $ 2.4 $ 2.4
Accumulated Amortization (1.5) (1.2)
Intangible Assets, Net $ 0.9 $ 1.2
Non-compete Agreement    
Finite Lived Intangible Assets [Line Items]    
Weighted- Average Amortization Period (in years) 5 years 5 years
Gross Amount $ 5.4 $ 5.4
Accumulated Amortization $ (5.4) $ (5.4)
Favorable Lease Contracts    
Finite Lived Intangible Assets [Line Items]    
Weighted- Average Amortization Period (in years) 120 years 120 years
Gross Amount $ 7.0 $ 7.0
Accumulated Amortization (0.2) (0.2)
Intangible Assets, Net $ 6.8 $ 6.8
v3.25.0.1
Goodwill and Intangible Assets - Schedule of Expected Amortization of Intangible Assets (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]    
2025 $ 4.5  
2026 4.5  
2027 4.5  
2028 4.4  
2029 4.1  
Thereafter 23.5  
Intangible Assets, Net $ 45.5 $ 50.0
v3.25.0.1
Employee Benefits - Additional Information (Details) - USD ($)
 3 Months Ended 12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Dec. 31, 2024
Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]        
Payment for other postretirement benefits     $ 1,100,000  
Postretirement Health Coverage | Salaried VEBA        
Defined Benefit Plan Disclosure [Line Items]        
Maximum contribution threshold     2,900,000 $ 2,900,000
Payment for other postretirement benefits   $ 1,100,000    
Postretirement Health Coverage | Scenario Forecast | Salaried VEBA        
Defined Benefit Plan Disclosure [Line Items]        
Payment for other postretirement benefits $ 700,000      
Pension Plans        
Defined Benefit Plan Disclosure [Line Items]        
Accumulated benefit obligation     29,800,000 $ 29,600,000
Expected employer contributions in 2025     $ 4,500,000  
Other Postretirement Benefits Plan        
Defined Benefit Plan Disclosure [Line Items]        
Health care cost trend rate assumed     7.70%  
Decreased rate of health care cost trend     4.50%  
v3.25.0.1
Employee Benefits - Assumptions Used to Determine Benefit Obligation (Details)
Dec. 31, 2024
Dec. 31, 2023
Salaried VEBA    
Defined Benefit Plan Disclosure [Line Items]    
Discount rate 5.40% 4.89%
Pension Plans    
Defined Benefit Plan Disclosure [Line Items]    
Discount rate 5.54% 4.95%
Rate of compensation increase 2.56% 2.63%
Other Postretirement Benefits Plan    
Defined Benefit Plan Disclosure [Line Items]    
Discount rate 5.48% 4.92%
v3.25.0.1
Employee Benefits - Schedule of Assumptions Used to Determine Net Periodic Postretirement and Postemployment Benefit Cost) (Details)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Salaried VEBA      
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 4.89% 5.10% 2.49%
Expected long-term return on plan assets 5.75% 5.75% 5.50%
Pension Plans      
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 5.00% 5.19% 2.90%
Expected long-term return on plan assets 6.31% 6.33% 6.02%
Rate of compensation increase 2.56% 2.63% 2.69%
Other Postretirement Benefits Plan      
Defined Benefit Plan Disclosure [Line Items]      
Discount rate 4.92% 5.14% 2.64%
v3.25.0.1
Employee Benefits - Benefit Obligations and Funded Status of Pension Plans, OPEB and Salaried VEBAs (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Salaried VEBA      
Change in benefit obligation:      
Obligation at beginning of year $ 46.9 $ 58.9  
Interest cost 2.2 2.9  
Prior service cost (credit)   (8.8)  
Actuarial (gain) loss (1.4) 0.4  
Benefits paid (4.8) (6.5)  
Obligation at end of year 42.9 46.9 $ 58.9
Change in plan assets:      
Fair market value of plan assets at beginning of year 43.1 42.4  
Actual return on assets 3.9 6.1  
Company contributions 0.7 1.1  
Benefits paid (4.8) (6.5)  
Fair market value of plan assets at end of year 42.9 43.1 42.4
Net funded status   (3.8)  
Cumulative gain (loss) recognized in Accumulated other comprehensive income:      
Accumulated net actuarial gain 8.2 5.2  
Prior service cost (14.3) (16.0)  
Total (6.1) (10.8)  
Pension Plans      
Change in benefit obligation:      
Obligation at beginning of year 30.5 18.8  
Foreign currency translation adjustment (0.5) 0.2  
Service cost 3.6 3.8 5.8
Interest cost 1.6 1.3 0.6
Prior service cost (credit) 2.2 6.6  
Actuarial (gain) loss (1.6) 0.2  
Plan participants contributions 0.1 0.1  
Benefits paid (0.7) (0.5)  
Settlements (4.5)    
Obligation at end of year 30.7 30.5 18.8
Change in plan assets:      
Fair market value of plan assets at beginning of year 20.5 14.9  
Foreign currency translation adjustment 0.3 0.2  
Actual return on assets 0.9 1.4  
Plan participants contributions 0.1 0.1  
Company contributions 5.9 4.4  
Benefits paid (0.7) (0.5)  
Settlements (4.5)    
Fair market value of plan assets at end of year 22.5 20.5 14.9
Net funded status (8.2) (10.0)  
Cumulative gain (loss) recognized in Accumulated other comprehensive income:      
Accumulated net actuarial gain 4.2 1.3  
Prior service cost (7.6) (6.1)  
Total (3.4) (4.8)  
Other Postretirement Benefits Plan      
Change in benefit obligation:      
Obligation at beginning of year 68.8 66.4  
Service cost 1.1 1.1 1.6
Interest cost 3.3 3.4 2.2
Actuarial (gain) loss (6.8) (0.7)  
Plan participants contributions 0.2 0.1  
Benefits paid (1.9) (1.5)  
Obligation at end of year 64.7 68.8 $ 66.4
Change in plan assets:      
Plan participants contributions 0.2 0.1  
Company contributions 1.7 1.4  
Benefits paid (1.9) (1.5)  
Net funded status (64.7) (68.8)  
Cumulative gain (loss) recognized in Accumulated other comprehensive income:      
Accumulated net actuarial gain 23.1 17.4  
Total $ 23.1 $ 17.4  
v3.25.0.1
Employee Benefits - Benefit Obligations and Funded Status of Pension Plans, OPEB and Salaried VEBAs (Parenthetical) (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]      
Actuarial gain (loss) due to change in discount rate   $ 2.2 $ (0.5)
Actuarial gain (loss) due to changes in census data   (0.3) 0.3
Actuarial gain (loss) recognized in conjuction   (0.3)  
Pension and Other Postretirement Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Funded (Unfunded) Status of Plan $ 9.8 9.8 11.3
Other Assets      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Funded (Unfunded) Status of Plan 1.6 1.6 1.3
Other Postretirement Benefits Plan      
Defined Benefit Plan Disclosure [Line Items]      
Actuarial gain (loss) due to change in discount rate   3.3 (1.4)
Actuarial gain (loss) due to changes in census data   6.5 2.5
Actuarial gain (loss) due to changes in projected depletion year   (2.9) 2.7
Actuarial gain (loss) due to changes in morbidity assumptions   3.2  
Actuarial gain (loss) due to change in trend rate   (3.3) (3.1)
Defined Benefit Plan, Funded (Unfunded) Status of Plan (64.7) (64.7) (68.8)
Other Postretirement Benefits Plan | Accrued Salaries and Wages and Related Expenses      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Funded (Unfunded) Status of Plan 3.1 3.1 3.3
Other Postretirement Benefits Plan | Pension and Other Postretirement Benefits      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Funded (Unfunded) Status of Plan 61.6 61.6 65.5
Pension Plans      
Defined Benefit Plan Disclosure [Line Items]      
Prior service cost (credit)   2.2 6.6
Defined Benefit Plan, Funded (Unfunded) Status of Plan (8.2) (8.2) (10.0)
Salaried VEBA      
Defined Benefit Plan Disclosure [Line Items]      
Prior service cost (credit)     (8.8)
Actuarial gain (loss) due to change in discount rate   1.4 (0.7)
Actuarial gain (loss) due to changes in census data   0.1 0.3
Actuarial gain (loss) due to change in trend rate   $ (0.1)  
Defined Benefit Plan, Funded (Unfunded) Status of Plan     $ (3.8)
Kaiser Aluminum Canada Limited Retirement Plan      
Defined Benefit Plan Disclosure [Line Items]      
Defined benefit plan, obligation associated for salaried employees $ 4.5    
v3.25.0.1
Employee Benefits - Expected Benefit Payments (Details)
$ in Millions
Dec. 31, 2024
USD ($)
Defined Benefit Plan Disclosure [Line Items]  
2025 $ 9.1
2026 9.8
2027 10.4
2028 11.0
2029 11.8
2030-2034 63.4
Salaried VEBA  
Defined Benefit Plan Disclosure [Line Items]  
2025 5.3
2026 5.1
2027 4.9
2028 4.6
2029 4.3
2030-2034 16.9
Pension Plans  
Defined Benefit Plan Disclosure [Line Items]  
2025 0.7
2026 0.9
2027 1.1
2028 1.3
2029 1.7
2030-2034 11.7
Other Postretirement Benefits Plan  
Defined Benefit Plan Disclosure [Line Items]  
2025 3.1
2026 3.8
2027 4.4
2028 5.1
2029 5.8
2030-2034 $ 34.8
v3.25.0.1
Employee Benefits - Expected Benefit Payments (Parenthetical) (Details) - USD ($)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Postretirement Health Coverage | Salaried VEBA    
Defined Benefit Plan Disclosure [Line Items]    
Maximum contribution threshold $ 2,900,000 $ 2,900,000
v3.25.0.1
Employee Benefits - Summary of Asset Class Allocation per Pension Plan Investment Policy and Weighted Average Asset Allocation (Details)
Dec. 31, 2024
Equities  
Defined Benefit Plan Disclosure [Line Items]  
Defined benefit plan, policy range, percentage 56.00%
Defined benefit plan, weighted average asset allocation, percentage 55.00%
Fixed Income  
Defined Benefit Plan Disclosure [Line Items]  
Defined benefit plan, policy range, percentage 38.00%
Defined benefit plan, weighted average asset allocation, percentage 38.00%
Real Estate Investments  
Defined Benefit Plan Disclosure [Line Items]  
Defined benefit plan, policy range, percentage 5.00%
Defined benefit plan, weighted average asset allocation, percentage 6.00%
Cash and Short-term Investments  
Defined Benefit Plan Disclosure [Line Items]  
Defined benefit plan, policy range, percentage 1.00%
Defined benefit plan, weighted average asset allocation, percentage 1.00%
v3.25.0.1
Employee Benefits - Fair Value of Plan Assets (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Salaried VEBA      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Defined Benefit Plan, Plan Assets, Amount $ 42.9 $ 43.1 $ 42.4
Pension Plans      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Defined Benefit Plan, Plan Assets, Amount 22.5 20.5 $ 14.9
Level 1 | Fair Value, Measurements, Recurring      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Defined Benefit Plan, Plan Assets, Amount 76.6 73.6  
Deferred compensation program - Diversified investment funds in registered investment companies 11.9 11.1  
Level 1 | Postretirement Health Coverage | Salaried VEBA | Equity Funds | Fair Value, Measurements, Recurring      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Defined Benefit Plan, Plan Assets, Amount 25.2 25.5  
Level 1 | Postretirement Health Coverage | Salaried VEBA | Fixed Income Funds | Fair Value, Measurements, Recurring      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Defined Benefit Plan, Plan Assets, Amount 16.8 16.5  
Level 1 | Postretirement Health Coverage | Salaried VEBA | Cash and Money Market Investments | Fair Value, Measurements, Recurring      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Defined Benefit Plan, Plan Assets, Amount 0.2    
Level 1 | Pension Plans | DiversifiedInvestment Funds in Pooled Separate Accounts | Fair Value, Measurements, Recurring      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Defined Benefit Plan, Plan Assets, Amount 17.1 11.2  
Level 1 | Pension Plans | Diversified Investment Funds In Registered Investment Companies | Fair Value, Measurements, Recurring      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Defined Benefit Plan, Plan Assets, Amount $ 5.4 $ 9.3  
v3.25.0.1
Employee Benefits - Summary of Total Expense Related to All Postretirement Benefit Plans (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]      
Net periodic postretirement and postemployment benefit cost relating to defined benefit plans $ 4.3 $ 8.4 $ 5.6
Postretirement Benefit Plans      
Defined Benefit Plan Disclosure [Line Items]      
Defined contribution plan, cost 18.6 18.1 17.1
Deferred compensation arrangement with individual, compensation expense 1.3 1.2 (0.6)
Multiemployer plan, contributions by employer 6.1 5.6 5.2
Net periodic postretirement and postemployment benefit cost relating to defined benefit plans 9.0 13.4 13.1
Total other employee benefit plans $ 35.0 $ 38.3 $ 34.8
v3.25.0.1
Employee Benefits - Summary of Total Expense Related to All Postretirement Benefit Plans (Parenthetical) (Details) - USD ($)
$ in Millions
 9 Months Ended 12 Months Ended
Dec. 31, 2024
Dec. 31, 2024
Defined Benefit Plan Disclosure [Line Items]    
Multiemployer pension plans excludes charge to restructuring costs   $ 4.6
Two Thousand And Twenty Four Restructuring Plan [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Multiemployer pension plans excludes charge to restructuring costs $ 4.6  
v3.25.0.1
Employee Benefits - Summary of Components of Net Periodic Postretirement Benefit Cost (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]      
Total net periodic postretirement and postemployment benefit cost $ 4.3 $ 8.4 $ 5.6
Salaried VEBA      
Defined Benefit Plan Disclosure [Line Items]      
Interest cost 2.2 2.9  
Pension Plans      
Defined Benefit Plan Disclosure [Line Items]      
Service cost 3.6 3.8 5.8
Interest cost 1.6 1.3 0.6
Expected return on plan assets (1.4) (1.1) (0.9)
Amortization of prior service cost 0.8 0.4  
Settlement gain recognized (0.5)    
Total net periodic postretirement and postemployment benefit cost 4.1 4.4 5.5
Other Postretirement Benefits Plan      
Defined Benefit Plan Disclosure [Line Items]      
Service cost 1.1 1.1 1.6
Interest cost 3.3 3.4 2.2
Amortization of net actuarial gain (1.1) (1.1)  
Total net periodic postretirement and postemployment benefit cost 3.3 3.4 3.8
Postretirement Health Coverage | Salaried VEBA      
Defined Benefit Plan Disclosure [Line Items]      
Service cost     0.1
Interest cost 2.2 2.9 1.9
Expected return on plan assets (2.2) (2.2) (3.1)
Amortization of prior service cost 1.7 4.9 4.9
Amortization of net actuarial gain (0.1)    
Total net periodic postretirement and postemployment benefit cost $ 1.6 $ 5.6 $ 3.8
v3.25.0.1
Multiemployer Pension Plans - Additional Information (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2024
USD ($)
Multiemployer Pension Plan Disclosure [Line Items]  
Percentage of employees participating in multiemployer pension plans to total employees 34.00%
Company's contributions to the multiemployer plans is less than 5.00%
Minimum  
Multiemployer Pension Plan Disclosure [Line Items]  
Estimated annual contribution to pension and other postretirement benefit plans $ 5.5
Maximum  
Multiemployer Pension Plan Disclosure [Line Items]  
Estimated annual contribution to pension and other postretirement benefit plans $ 6.5
v3.25.0.1
Multiemployer Pension Plans - Multiemployer Pension Plan Description and Contributions (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Multiemployer Pension Plan Disclosure [Line Items]      
Entity Tax Identification Number 94-3030279    
Contributions of the Company $ 6.1 $ 5.6 $ 5.2
USW Plan      
Multiemployer Pension Plan Disclosure [Line Items]      
Entity Tax Identification Number 23-6648508    
Pension Protection Act Zone Status Green Green  
FIP/RP Status Pending/Implemented in 2022 No    
Contributions of the Company $ 4.7 $ 4.2 3.8
Surcharge Imposed in 2022 No    
USW Plan | Minimum      
Multiemployer Pension Plan Disclosure [Line Items]      
Expiration Date of Collective-Bargaining Agreement Sep. 30, 2025    
USW Plan | Maximum      
Multiemployer Pension Plan Disclosure [Line Items]      
Expiration Date of Collective-Bargaining Agreement Nov. 30, 2026    
Other Funds      
Multiemployer Pension Plan Disclosure [Line Items]      
Contributions of the Company $ 1.4 $ 1.4 $ 1.4
v3.25.0.1
Multiemployer Pension Plans - Multiemployer Pension Plan Description and Contributions (Parenthetical) (Details)
 6 Months Ended 12 Months Ended
Dec. 31, 2024
Agreement
$ / shares
Jun. 30, 2024
$ / shares
Dec. 31, 2024
Agreement
$ / shares
Multiemployer Pension Plan Disclosure [Line Items]      
Green zone funding percentage     80.00%
USW Plan      
Multiemployer Pension Plan Disclosure [Line Items]      
Number of collective-bargaining agreements | Agreement 3   3
USW Plan | Newark and Trentwood Facilities      
Multiemployer Pension Plan Disclosure [Line Items]      
Percentage of employees covered by bargaining agreement     87.00%
USW Plan | Newark and Trentwood Facilities | Starting in July Two Thousand Twenty      
Multiemployer Pension Plan Disclosure [Line Items]      
Monthly contributions per hour worked by each bargaining unit employee $ 2.06 $ 1.75  
USW Plan | Richmond (Bellwood), Virginia Facility      
Multiemployer Pension Plan Disclosure [Line Items]      
Percentage of employees covered by bargaining agreement     10.00%
Monthly contributions per hour worked by each bargaining unit employee     $ 1.50
USW Plan | Florence, Alabama Facility      
Multiemployer Pension Plan Disclosure [Line Items]      
Percentage of employees covered by bargaining agreement     3.00%
Monthly contributions per hour worked by each bargaining unit employee     $ 1.35
v3.25.0.1
Employee Incentive Plans - Additional Information (Details) - 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]      
Shares available for awards (shares) 603,948    
Recognized tax benefit relating to non-cash compensation expense $ 3.2 $ 3.6 $ 3.2
Share-based Compensation Arrangement by Share-based Payment Award, stock units, vested in period, fair value $ 8.5 $ 6.2 $ 9.1
Restricted stock units (RSUs)      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Number of common share received by the employee on vesting 1    
Service period 3 years    
Restricted Stock      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Service period 1 year    
Performance Shares      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Number of common share received by the employee on vesting 1    
Performance Shares | Tranche One      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Performance period 3 years    
Performance Shares | Tranche Two      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Performance period 3 years    
Performance Shares | Tranche Four      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Performance period 3 years    
Performance Shares | Minimum      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Number of performance shares that may be earned, as a percentage (percent) 0.00%    
Performance Shares | Maximum      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Number of performance shares that may be earned, as a percentage (percent) 200.00%    
Accrued salaries, wages and related expenses      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Accrued salaries, wages and related expenses $ 13.3    
v3.25.0.1
Employee Incentive Plans - Summary of RSAs and RSUs Activity (Details) - Restricted Stock and Restricted Stock Units - $ / shares
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Shares, Outstanding Beginning Balance 399,387    
Shares, Granted 132,490    
Shares, Vested (107,831)    
Shares, Forfeited (15,372)    
Shares, Outstanding Ending Balance 408,674 399,387  
Weighted-Average Grant-Date Fair Value per Share, Outstanding Beginning Balance $ 80.41    
Weighted-Average Grant-Date Fair Value per Share, Granted 64.84 $ 71.81 $ 84.16
Weighted-Average Grant-Date Fair Value per Share, Vested 97.57    
Weighted-Average Grant-Date Fair Value per Share, Forfeited 70.99    
Weighted-Average Grant-Date Fair Value per Share, Outstanding Ending Balance $ 71.19 $ 80.41  
v3.25.0.1
Employee Incentive Plans - Summary of Weighted Average Inputs and Assumptions Used to Calculate Fair Value at Grant Date (Details) - TSR-Based Performance Shares - $ / shares
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Grant date fair value $ 96.34 $ 104.87 $ 122.22
Grant date stock price $ 71.76 $ 84.33 $ 95.13
Expected volatility of Kaiser Aluminum 45.59% 49.72% 49.37%
Expected volatility of peer companies 38.67% 45.14% 51.08%
Risk-free interest rate 4.31% 4.59% 1.59%
Dividend yield 4.29% 3.65% 3.24%
v3.25.0.1
Employee Incentive Plans - Summary of Weighted Average Inputs and Assumptions Used to Calculate Fair Value at Grant Date (Parenthetical) (Details)
 12 Months Ended
Dec. 31, 2024
TSR-Based Performance Shares  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Term of awards remaining 2 years 9 months 18 days
v3.25.0.1
Employee Incentive Plans - Summary of Performance Shares Activity (Details) - Performance Shares - $ / shares
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Shares, Outstanding Beginning Balance 328,616    
Shares, Granted 175,662    
Shares, Forfeited (7,060)    
Shares, canceled (100,212)    
Shares, Outstanding Ending Balance 397,006 328,616  
Weighted-Average Grant-Date Fair Value per Share, Outstanding Beginning Balance $ 114.79    
Weighted-Average Grant-Date Fair Value per Share, Granted 86.50 $ 96.65 $ 111.37
Weighted-Average Grant-Date Fair Value per Share, Forfeited 94.84    
Weighted-Average Grant-Date Fair Value per Share, Canceled 137.07    
Weighted-Average Grant-Date Fair Value per Share, Outstanding Ending Balance $ 97.00 $ 114.79  
v3.25.0.1
Employee Incentive Plans - Summary of Non-Cash Compensation Expense under LTI Programs (Details) - 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]      
Total non-cash compensation expense $ 13.8 $ 15.4 $ 13.7
Restricted Stock and Restricted Stock Units      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Total non-cash compensation expense 8.9 10.7 8.8
Performance Shares      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Total non-cash compensation expense $ 4.9 $ 4.7 $ 4.9
v3.25.0.1
Employee Incentive Plans - Summary of Unrecognized Gross Compensation Cost and Expected Period Over Which Remaining Gross Compensation Costs Will Be Recognized By Type of Award (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2024
USD ($)
Restricted Stock and Restricted Stock Units  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Unrecognized Gross Compensation Costs $ 12.6
Expected Period (in years) Over Which the Remaining Gross Compensation Costs Will Be Recognized 2 years 1 month 6 days
Performance Shares  
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Unrecognized Gross Compensation Costs $ 6.1
Expected Period (in years) Over Which the Remaining Gross Compensation Costs Will Be Recognized 1 year 9 months 18 days
v3.25.0.1
Employee Incentive Plans - Summary of Weighted-Average Grant-Date Fair Value per Share for Shares Granted by Type of Award (Details) - $ / shares
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Restricted Stock and Restricted Stock Units      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Grant date fair value $ 64.84 $ 71.81 $ 84.16
Performance Shares      
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]      
Grant date fair value $ 86.50 $ 96.65 $ 111.37
v3.25.0.1
Derivatives, Hedging Programs and Other Financial Instruments - Additional Information (Details) - USD ($)
Dec. 31, 2024
Dec. 31, 2023
Derivative [Line Items]    
Collateral posted for net derivatives $ 0 $ 0
Cash collateral posted from customers 0 0
Designated as Hedging Instrument | Purchase    
Derivative [Line Items]    
Derivative net liability 800,000 1,000,000
Not Designated as Hedging Instrument    
Derivative [Line Items]    
Oustanding amount $ 0 $ 0
v3.25.0.1
Derivatives, Hedging Programs and Other Financial Instruments - Summary of Derivative Positions (Details) - 12 months ended Dec. 31, 2024
Mmlb in Millions
EUR (€)
Mmlb
MMBTU
GBP (£)
MMBTU
Mmlb
Purchase | Aluminum    
Derivative [Line Items]    
Derivative non-monetary notional amount 57.8 57.8
Purchase | Aluminum | Minimum    
Derivative [Line Items]    
Derivative maturity period Jan. 31, 2025  
Purchase | Aluminum | Maximum    
Derivative [Line Items]    
Derivative maturity period Apr. 30, 2026  
Purchase | Fixed Price Purchase Contracts for MWTP    
Derivative [Line Items]    
Derivative non-monetary notional amount 49.9 49.9
Purchase | Fixed Price Purchase Contracts for MWTP | Minimum    
Derivative [Line Items]    
Derivative maturity period Jan. 31, 2025  
Purchase | Fixed Price Purchase Contracts for MWTP | Maximum    
Derivative [Line Items]    
Derivative maturity period Apr. 30, 2026  
Purchase | Alloying Metals    
Derivative [Line Items]    
Derivative non-monetary notional amount 9.0 9.0
Purchase | Alloying Metals | Minimum    
Derivative [Line Items]    
Derivative maturity period Jan. 31, 2025  
Purchase | Alloying Metals | Maximum    
Derivative [Line Items]    
Derivative maturity period Dec. 31, 2026  
Purchase | Natural Gas    
Derivative [Line Items]    
Derivative non-monetary notional amount | MMBTU 2,760,000 2,760,000
Purchase | Natural Gas | Minimum    
Derivative [Line Items]    
Derivative maturity period Jan. 31, 2025  
Purchase | Natural Gas | Maximum    
Derivative [Line Items]    
Derivative maturity period Dec. 31, 2026  
Purchase | Euro    
Derivative [Line Items]    
Derivative notional amount | € € 7,236,092  
Purchase | Euro | Minimum    
Derivative [Line Items]    
Derivative maturity period Jan. 31, 2025  
Purchase | Euro | Maximum    
Derivative [Line Items]    
Derivative maturity period Jul. 31, 2027  
Purchase | British Pounds    
Derivative [Line Items]    
Derivative notional amount | £   £ 20,000
Purchase | British Pounds | Minimum    
Derivative [Line Items]    
Derivative maturity period Jan. 31, 2025  
Purchase | British Pounds | Maximum    
Derivative [Line Items]    
Derivative maturity period Feb. 28, 2025  
Sales | Aluminum    
Derivative [Line Items]    
Derivative maturity period Jan. 31, 2025  
Derivative non-monetary notional amount 10.5 10.5
Sales | Fixed Price Sale Contracts for MWTP    
Derivative [Line Items]    
Derivative maturity period Jan. 31, 2025  
Derivative non-monetary notional amount 10.5 10.5
v3.25.0.1
Derivatives, Hedging Programs and Other Financial Instruments - Summary of (Gain) Loss Associated with Derivative Contracts (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Derivative Instruments Gain Loss [Line Items]      
Total of income and expense line items presented in our Statements of Consolidated Income (loss) in which the effects of cashflow hedges are recorded $ 2,691.1 $ 2,754.9 $ 3,180.2
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Total of income and expense line items presented in our Statements of Consolidated Income (loss) in which the effects of cashflow hedges are recorded Total of income and expense line items presented in our Statements of Consolidated Income (loss) in which the effects of cashflow hedges are recorded Total of income and expense line items presented in our Statements of Consolidated Income (loss) in which the effects of cashflow hedges are recorded
Not Designated as Hedging Instrument      
Derivative Instruments Gain Loss [Line Items]      
Loss (gain) recognized in our Statements of Consolidated Income (Loss) $ 5.0 $ 0.1 $ 0.9
Not Designated as Hedging Instrument | Alloying Metals      
Derivative Instruments Gain Loss [Line Items]      
Loss (gain) recognized in our Statements of Consolidated Income (Loss)   0.1 (0.5)
Loss (gain) recognized in our Statements of Consolidated Income (Loss) - Unrealized mark-to-market loss     1.4
Not Designated as Hedging Instrument | Electricity      
Derivative Instruments Gain Loss [Line Items]      
Loss (gain) recognized in our Statements of Consolidated Income (Loss) 5.0    
Cash Flow Hedges      
Derivative Instruments Gain Loss [Line Items]      
Total of income and expense line items presented in our Statements of Consolidated Income (loss) in which the effects of cashflow hedges are recorded 2,691.1 2,754.9 3,180.2
Cash Flow Hedges | Designated as Hedging Instrument      
Derivative Instruments Gain Loss [Line Items]      
Loss (gain) recognized in our Statements of Consolidated Income (Loss) (0.9) 12.9 (10.5)
Cash Flow Hedges | Designated as Hedging Instrument | Aluminum      
Derivative Instruments Gain Loss [Line Items]      
Loss (gain) recognized in our Statements of Consolidated Income (Loss) (1.4) 12.8 7.4
Cash Flow Hedges | Designated as Hedging Instrument | Alloying Metals      
Derivative Instruments Gain Loss [Line Items]      
Loss (gain) recognized in our Statements of Consolidated Income (Loss) (1.1)    
Cash Flow Hedges | Designated as Hedging Instrument | Natural Gas      
Derivative Instruments Gain Loss [Line Items]      
Loss (gain) recognized in our Statements of Consolidated Income (Loss) 1.0 $ 0.1 (6.6)
Cash Flow Hedges | Designated as Hedging Instrument | Electricity      
Derivative Instruments Gain Loss [Line Items]      
Loss (gain) recognized in our Statements of Consolidated Income (Loss) $ 0.6   $ (11.3)
v3.25.0.1
Derivatives, Hedging Programs and Other Financial Instruments - Schedule of Fair Value of Derivative Financial Instruments (Details) - USD ($)
Dec. 31, 2024
Dec. 31, 2023
Designated as Hedging Instrument | Purchase    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Liabilities $ (800,000) $ (1,000,000)
Not Designated as Hedging Instrument    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Net Amount 0 0
Fair Value, Measurements, Recurring    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets 4,000,000.0 5,900,000
Liabilities (2,100,000) (2,900,000)
Fair Value, Measurements, Recurring | Level 1    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets 4,000,000.0 5,900,000
Liabilities (2,100,000) (2,900,000)
Net Amount 1,900,000 3,000,000.0
Fair Value, Measurements, Recurring | Cash Flow Hedges | Level 1 | Designated as Hedging Instrument | Purchase | Natural Gas    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets 500,000 300,000
Liabilities (800,000) (900,000)
Net Amount (300,000) (600,000)
Fair Value, Measurements, Recurring | Cash Flow Hedges | Level 1 | Designated as Hedging Instrument | Purchase | Aluminum    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets 1,100,000 3,400,000
Liabilities (800,000) (600,000)
Net Amount 300,000 2,800,000
Fair Value, Measurements, Recurring | Cash Flow Hedges | Level 1 | Designated as Hedging Instrument | Purchase | Fixed Price Purchase Contracts for MWTP    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets 1,100,000 400,000
Liabilities   (300,000)
Net Amount 1,100,000 100,000
Fair Value, Measurements, Recurring | Cash Flow Hedges | Level 1 | Designated as Hedging Instrument | Purchase | Fixed Price Sale Contracts For MWTP    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets   100,000
Liabilities   (200,000)
Net Amount   (100,000)
Fair Value, Measurements, Recurring | Cash Flow Hedges | Level 1 | Designated as Hedging Instrument | Purchase | Foreign Currency    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets   500,000
Liabilities (400,000)  
Net Amount (400,000) 500,000
Fair Value, Measurements, Recurring | Cash Flow Hedges | Level 1 | Designated as Hedging Instrument | Purchase | Alloying Metals    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets 1,300,000 700,000
Liabilities (100,000) (100,000)
Net Amount $ 1,200,000 600,000
Fair Value, Measurements, Recurring | Cash Flow Hedges | Level 1 | Designated as Hedging Instrument | Purchase | Electricity    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Assets   500,000
Liabilities   (600,000)
Net Amount   (100,000)
Fair Value, Measurements, Recurring | Cash Flow Hedges | Level 1 | Designated as Hedging Instrument | Sales | Aluminum    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Liabilities   (200,000)
Net Amount   $ (200,000)
v3.25.0.1
Derivatives, Hedging Programs and Other Financial Instruments - Schedule of Total Amounts of Derivative Assets and Liabilities on Balance Sheets (Details) - Fair Value, Measurements, Recurring - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Derivative [Line Items]    
Derivative asset current $ 3.7 $ 4.8
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration] Prepaid Expense and Other Assets, Current Prepaid Expense and Other Assets, Current
Derivative asset noncurrent $ 0.3 $ 1.1
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] Other Assets, Noncurrent Other Assets, Noncurrent
Total derivative assets $ 4.0 $ 5.9
Derivative Asset, Statement of Financial Position [Extensible Enumeration] Assets Assets
Derivative liabilities current $ (1.8) $ (2.4)
Derivative Liability, Current, Statement of Financial Position [Extensible Enumeration] Other Accrued Liabilities, Current Other Accrued Liabilities, Current
Derivative liabilities noncurrent $ (0.3) $ (0.5)
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Other Liabilities, Noncurrent Other Liabilities, Noncurrent
Total derivative liabilities $ (2.1) $ (2.9)
Derivative Liability, Statement of Financial Position [Extensible Enumeration] Liabilities Liabilities
v3.25.0.1
Debt and Credit Facility (Senior Notes) - Additional Information (Details) - Senior Notes - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Debt Instrument [Line Items]    
Debt instrument aggregate principal amount $ 1,050.0 $ 1,050.0
4.50% Senior Notes    
Debt Instrument [Line Items]    
Debt instrument contractual rate (percent) 4.50% 4.50%
Debt instrument aggregate principal amount $ 550.0 $ 550.0
4.625% Senior Notes    
Debt Instrument [Line Items]    
Debt instrument contractual rate (percent) 4.625% 4.625%
Debt instrument aggregate principal amount $ 500.0 $ 500.0
v3.25.0.1
Debt and Credit Facility - Summary of Senior Notes (Details) - Senior Notes - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Debt Instrument [Line Items]    
Total debt $ 1,050.0 $ 1,050.0
Unamortized issuance costs (8.4) (10.2)
Total carrying amount $ 1,041.6 1,039.8
4.50% Senior Notes    
Debt Instrument [Line Items]    
Issuance Date May 31, 2021  
Debt Instrument, Maturity Date Jun. 30, 2031  
Effective interest rate (percent) 4.70%  
Total debt $ 550.0 550.0
4.625% Senior Notes    
Debt Instrument [Line Items]    
Issuance Date Nov. 30, 2019  
Debt Instrument, Maturity Date Mar. 31, 2028  
Effective interest rate (percent) 4.80%  
Total debt $ 500.0 $ 500.0
v3.25.0.1
Debt and Credit Facility - Summary of Senior Notes (Parenthetical) (Details) - Senior Notes
Dec. 31, 2024
Dec. 31, 2023
4.50% Senior Notes    
Debt Instrument [Line Items]    
Debt instrument contractual rate (percent) 4.50% 4.50%
4.625% Senior Notes    
Debt Instrument [Line Items]    
Debt instrument contractual rate (percent) 4.625% 4.625%
v3.25.0.1
Debt and Credit Facility - Summary of Fair Value of Outstanding Senior Notes (Details) - Senior Notes - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
4.625% Senior Notes    
Debt Instrument [Line Items]    
Fair value of outstanding senior notes $ 470.1 $ 462.4
4.50% Senior Notes    
Debt Instrument [Line Items]    
Fair value of outstanding senior notes $ 484.8 $ 474.1
v3.25.0.1
Debt and Credit Facility (Revolving Credit Facility) - Additional Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Oct. 31, 2019
Dec. 31, 2024
Dec. 31, 2023
Apr. 30, 2022
Debt Instrument [Line Items]        
Total borrowings incurred     $ 215.1  
Amended Credit Agreement        
Debt Instrument [Line Items]        
Line of credit mature description   As amended, the Revolving Credit Facility contains a maximum commitment amount of $575.0 million (of which up to a maximum of $50.0 million may be utilized for letters of credit) and is set to mature in April 2027.    
Revolving Credit Facility        
Debt Instrument [Line Items]        
Line of credit facility, maximum borrowing capacity   $ 575.0    
Outstanding borrowings   $ 0.0 0.0  
Total borrowings incurred     $ 215.1  
Revolving Credit Facility | Amended Credit Agreement        
Debt Instrument [Line Items]        
Line of credit facility, maximum borrowing capacity       $ 575.0
Revolving Credit Facility | Prime Rate        
Debt Instrument [Line Items]        
Line of credit maximum revolving commitment 0.50%      
Line of credit facility Less than unused capacity commitment 40.00%      
Effective interest rate (percent) 0.25%      
Revolving Credit Facility | SOFR | Amended Credit Agreement        
Debt Instrument [Line Items]        
Line of credit maximum revolving commitment 1.50%      
Line of credit facility Less than unused capacity commitment 40.00%      
Effective interest rate (percent) 1.35%      
Revolving Credit Facility | Letter of Credit | Amended Credit Agreement        
Debt Instrument [Line Items]        
Line of credit facility, maximum borrowing capacity       $ 50.0
v3.25.0.1
Debt and Credit Facility - Schedule of Availability and Usage of Revolving Credit Facility (Details) - Revolving Credit Facility - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Line Of Credit Facility [Line Items]    
Revolving Credit Facility borrowing commitment $ 575.0  
Borrowing base availability 575.0  
Less: Outstanding borrowings under Revolving Credit Facility 0.0 $ 0.0
Less: Outstanding letters of credit under Revolving Credit Facility (21.6)  
Remaining borrowing availability $ 553.4  
v3.25.0.1
Debt and Credit Facility - Summary of Interest Expense Relating to Senior Notes and Revolving Credit Facility (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Debt Instrument [Line Items]      
Interest expense on finance lease liabilities $ 0.8 $ 0.7 $ 0.3
Total interest expense 43.7 46.9 48.3
Senior Notes and Revolving Credit Facility      
Debt Instrument [Line Items]      
Interest expense on finance lease liabilities 0.8 0.7 0.3
Interest expense capitalized as construction in progress (9.1) (6.4) (3.6)
Total interest expense 43.7 46.9 48.3
Revolving Credit Facility      
Debt Instrument [Line Items]      
Revolving Credit Facility interest expense, including commitment fees and finance cost amortization 2.4 3.0 2.0
Senior Notes      
Debt Instrument [Line Items]      
Senior Notes interest expense, including debt issuance cost amortization $ 49.6 $ 49.6 $ 49.6
v3.25.0.1
Debt and Credit Facility - Schedule of Future Principal Payments for Senior Notes and Revolving Credit Facility (Details) - Senior Notes and Revolving Credit Facility
$ in Millions
Dec. 31, 2024
USD ($)
Debt Instrument [Line Items]  
2028 $ 500.0
Thereafter 550.0
Total carrying amount $ 1,050.0
v3.25.0.1
Commitments and Contingencies - Summary of Activities Relating to Company's CARO Liabilities (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]      
Beginning balance $ 10.9 $ 10.1 $ 7.2
Liabilities added during the period     2.3
Liabilities settled during the period (0.1)   (0.1)
Accretion expense 0.9 0.8 0.7
Ending balance $ 11.7 $ 10.9 $ 10.1
v3.25.0.1
Commitments and Contingencies - Additional Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Environmental Contingency        
Environmental accrual $ 18.4 $ 17.0 $ 17.7 $ 16.8
Expected period related to remediation expenditures for environmental contingencies period 30 years      
Potential increase in environmental costs $ 13.4      
Time period within which recorded estimate of its environmental obligation may change 12 months      
Estimated final remediation cost feasibility study expected occur year 2025      
Weighted-average Credit-adjusted Risk-free Rate        
Environmental Contingency        
Weighted-average credit-adjusted risk-free rate (percent) 8.30% 8.26%    
v3.25.0.1
Commitments and Contingencies - Schedule of Changes in Environmental Contingencies (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Accrual for Environmental Loss Contingencies [Roll Forward]      
Beginning balance $ 17.0 $ 17.7 $ 16.8
Additional accruals 4.2 1.2 3.2
Less: expenditures (2.8) (1.9) (2.3)
Ending balance $ 18.4 $ 17.0 $ 17.7
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration] Other Liabilities, Noncurrent Other Liabilities, Noncurrent Other Liabilities, Noncurrent
v3.25.0.1
Accumulated Other Comprehensive Income - Schedule of Accumulated Other Comprehensive Income (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]      
Beginning balance $ 652.2 $ 631.2 $ 692.5
Other comprehensive (loss) income, net of tax 7.4 9.9 6.9
Ending balance 668.0 652.2 631.2
Defined Benefit Plans:      
AOCI Attributable to Parent, Net of Tax [Roll Forward]      
Beginning balance 11.0 2.8 (21.4)
Less: income tax benefit (expense) [1] (0.1) (1.0) (1.2)
Net (gain) loss reclassified from AOCI to Net income (loss) 0.4 3.2 3.7
Other comprehensive (loss) income, net of tax 8.1 8.2 24.2
Ending balance 19.1 11.0 2.8
Defined Benefit Plans: Net Actuarial Gain      
AOCI Attributable to Parent, Net of Tax [Roll Forward]      
Unrealized loss on cash flow hedges 12.2 4.3 27.0
Less: income tax benefit (expense) (2.8) (1.0) (6.5)
Net unrealized gain (loss) on available for sale securities, cash flow hedges and fair value hedges 9.4 3.3 20.5
Reclassification from AOCI [2],[3] (2.0) (1.1)  
Defined Benefit Plans: Net Prior Service (Cost) Credit      
AOCI Attributable to Parent, Net of Tax [Roll Forward]      
Unrealized loss on cash flow hedges (2.2) 2.2  
Less: income tax benefit (expense) 0.5 (0.5)  
Net unrealized gain (loss) on available for sale securities, cash flow hedges and fair value hedges (1.7) 1.7  
Reclassification from AOCI [3] 2.5 5.3 4.9
Cash Flow Hedges:      
AOCI Attributable to Parent, Net of Tax [Roll Forward]      
Beginning balance 2.1 [4] 0.4 [4] 17.7
Unrealized loss on cash flow hedges (0.2) (10.7) (12.2)
Less: income tax benefit (expense)   2.5 2.9
Net unrealized gain (loss) on available for sale securities, cash flow hedges and fair value hedges (0.2) (8.2) (9.3)
Reclassification from AOCI (0.9) 12.9 (10.5)
Reclassification due to forecasted transactions probable of not occurring 0.2    
Less: income tax benefit (expense) [1] 0.2 (3.0) 2.5
Net (gain) loss reclassified from AOCI to Net income (loss) (0.5) 9.9 (8.0)
Other comprehensive (loss) income, net of tax (0.7) 1.7 (17.3)
Ending balance [4] 1.4 2.1 0.4
Accumulated Other Comprehensive (Loss) Income      
AOCI Attributable to Parent, Net of Tax [Roll Forward]      
Beginning balance 13.1 3.2 (3.7)
Other comprehensive (loss) income, net of tax 7.4 9.9 6.9
Ending balance $ 20.5 $ 13.1 $ 3.2
[1] Income tax amounts reclassified out of AOCI were included as a component of Income tax (provision) benefit.
[2] Amounts amortized out of AOCI during the year ended December 31, 2024 include net actuarial gains recognized on a pro-rata basis in conjunction with a group annuity purchase (see Note 5).
[3] Amounts amortized out of AOCI related to pension and other postretirement and postemployment benefits were included within Net periodic postretirement and postemployment benefit cost (see Note 5).
[4] As of December 31, 2024, we estimate a net mark-to-market gain before tax of $1.9 million in AOCI will be reclassified into Net income (loss) upon settlement within the next 12 months.
v3.25.0.1
Accumulated Other Comprehensive Income- Schedule of Accumulated Other Comprehensive Income (Parenthetical) (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2024
USD ($)
Equity [Abstract]  
Estimated net mark-to-market gain before tax within next twelve months - cash flow hedges $ 1.9
v3.25.0.1
Restructuring - Additional Information (Details) - USD ($)
$ in Millions
 9 Months Ended 12 Months Ended 18 Months Ended
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Mar. 31, 2024
Restructuring Cost and Reserve [Line Items]          
Restructuring costs   $ 7.6 $ 5.0 $ 2.2  
Pension obligation expected to be paid   $ 4.6      
Multiemployer pension obligation expected payment year   2027      
2022 Plan          
Restructuring Cost and Reserve [Line Items]          
Restructuring costs   $ 0.1 $ 5.0 $ 2.2 $ 7.3
2024 Plan          
Restructuring Cost and Reserve [Line Items]          
Restructuring costs $ 7.5 $ 7.5      
Pension obligation expected to be paid 4.6        
Severance charge $ 2.9        
v3.25.0.1
Restructuring - Summary of Activity Relating to Restructuring Plan Liabilities (Details) - USD ($)
$ in Millions
 9 Months Ended 12 Months Ended 18 Months Ended
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Mar. 31, 2024
Restructuring Cost and Reserve [Line Items]          
Restructuring costs   $ 7.6 $ 5.0 $ 2.2  
2024 Plan          
Restructuring Cost and Reserve [Line Items]          
Beginning balance   0.0      
Restructuring costs $ 7.5 7.5      
Costs paid or otherwise settled   (2.8)      
Ending balance 4.7 4.7 0.0    
2022 Plan          
Restructuring Cost and Reserve [Line Items]          
Beginning balance   1.2 1.7 0.0  
Restructuring costs   0.1 5.0 2.2 $ 7.3
Costs paid or otherwise settled   (1.3) (5.5) (0.5)  
Ending balance $ 0.0 $ 0.0 $ 1.2 $ 1.7  
v3.25.0.1
Restructuring - Summary of Activity Relating to Restructuring Plan Liabilities (Parenthetical) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
2024 Plan      
Restructuring Cost and Reserve [Line Items]      
Cash Paid $ 2.6    
2022 Plan      
Restructuring Cost and Reserve [Line Items]      
Cash Paid $ 1.2 $ 5.0 $ 0.4
v3.25.0.1
Other Income, Net - Components of Other Income, Net (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Other Income and Expenses [Abstract]      
Interest income $ 3.6 $ 1.7 $ 1.3
Net periodic postretirement and postemployment benefit cost (4.3) (8.4) (5.6)
Unrealized gain (loss) on equity securities 0.3 0.6 (1.2)
Gain on disposition of property, plant and equipment 3.8 13.8 6.0
Gain on business interruption insurance recoveries [1] $ 16.3 $ 0.0 $ 0.0
Gain on Business Interruption Insurance Recovery, Statement of Income or Comprehensive Income [Extensible Enumeration] Costs and Expenses Costs and Expenses Costs and Expenses
Post-acquisition funding received from Alcoa Corporation [2] $ 0.0 $ 0.0 $ 6.0
All other, net (0.2) (0.3) (0.1)
Other income, net $ 19.5 $ 7.4 $ 6.4
[1] Represents advances against business interruption insurance claims. We recognize such advances in the period in which the insurance proceeds are received or become realizable. As of December 31, 2024 we received net cash proceeds of $15.9 million.
[2] Represents reimbursement received for repairs and maintenance expenditures on certain machinery and equipment that we had purchased from Alcoa in connection with our March 31, 2021 acquisition of Warrick.
v3.25.0.1
Other Income, Net - Components of Other Income, Net - (Parenthetical) (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2024
USD ($)
Other Income and Expenses [Abstract]  
Proceeds from insurance business interruption policy $ 15.9
v3.25.0.1
Other Income, Net - Additional Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Other Income and Expenses [Abstract]    
Trade accounts receivable sold $ 1,078.6 $ 1,240.6
Net discount fees recognized $ 24.8 $ 29.7
v3.25.0.1
Income Tax Matters - Income (Loss) Before Income Taxes by Geographic Area (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Income Tax Disclosure [Abstract]      
Domestic $ 53.5 $ 48.0 $ (44.6)
Foreign 10.0 8.3 6.7
Income (loss) before income taxes $ 63.5 $ 56.3 $ (37.9)
v3.25.0.1
Income Tax Matters - Income Tax (Provision) Benefit (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Federal income tax (expense) benefit      
Current federal tax (expense) benefit $ (3.5)    
Deferred federal income tax (expense) benefit (10.9) $ (11.6) $ 8.9
Federal benefit (expense) applied to decrease (increase) AOCI 1.9 2.5 1.7
Federal income tax (provision) benefit (12.5) (9.1) 10.6
Foreign income tax (expense) benefit      
Current foreign tax (expense) benefit (3.1) (2.2) (1.1)
Deferred foreign income tax (expense) benefit 0.6 0.1 (0.8)
Foreign benefit (expense) applied to decrease (increase) AOCI 0.0 0.1 0.2
Foreign income tax (provision) benefit (2.5) (2.0) (1.7)
State income tax (expense) benefit      
Current state tax (expense) benefit (3.3) 0.6 (2.5)
Deferred state income tax (expense) benefit 1.3 1.0 1.6
State benefit (expense) applied to decrease (increase) AOCI 0.3 0.4 0.3
State income tax (provision) benefit (1.7) 2.0 (0.6)
Total income tax (expense) benefit      
Current tax (expense) benefit (9.9) (1.6) (3.6)
Deferred income tax (expense) benefit (9.0) (10.5) 9.7
Benefit (expense) applied to decrease (increase) AOCI 2.2 3.0 2.2
Income tax (provision) benefit $ (16.7) $ (9.1) $ 8.3
v3.25.0.1
Income Tax Matters - Reconciliation of Income Tax (Provision) Benefit based on Effective Income Tax Rate and Statutory Tax Rate (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Reconciliation between income tax provision and statutory income tax provision:      
Amount of federal income tax (provision) benefit based on the statutory rate $ (13.3) $ (11.8) $ 8.0
Decrease in federal valuation allowances 0.0 0.0 1.1
Non-deductible compensation expense (2.2) (1.6) (0.9)
Non-deductible (expense) benefit (0.2) 0.2 (1.0)
State income tax (provision) benefit, net of federal benefit (1.4) 1.5 (0.5)
Research and development credit 1.2 3.2 2.2
Foreign income tax expense (0.4) (0.3) (0.3)
Foreign undistributed earnings (0.4) (0.3) (0.3)
Income tax (provision) benefit $ (16.7) $ (9.1) $ 8.3
v3.25.0.1
Income Tax Matters - Reconciliation of Income Tax (Provision) Benefit based on Effective Income Tax Rate and Statutory Tax Rate (Parenthetical) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Reconciliation between income tax provision and statutory income tax provision:      
Increase (decrease) in federal valuation allowances $ 0.0 $ 0.0 $ 1.1
Total state income tax (provision) benefit 1.4 (1.5) 0.5
Current state income tax provision 3.3 (0.6) 2.5
State and Local Jurisdiction      
Reconciliation between income tax provision and statutory income tax provision:      
Increase (decrease) in federal valuation allowances (2.8) 1.0 (0.1)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount 2.9 1.9 (1.5)
Total state income tax (provision) benefit (1.4) 1.5 (0.5)
Current state income tax provision $ 1.5 $ 1.4 $ (1.1)
v3.25.0.1
Income Tax Matters - Deferred Tax Assets and Liabilities (Details) - USD ($)
$ in Millions
Dec. 31, 2024
Dec. 31, 2023
Deferred income tax assets:    
Loss and credit carryforwards $ 17.3 $ 39.6
Defined benefit plans 3.1 3.6
Other assets 35.8 36.8
Lease assets 7.2 8.7
Inventories 39.8 29.5
Excess interest carryforward 10.2 14.0
Research & development capitalization 19.1 16.9
Valuation allowances (5.5) (2.7)
Total deferred income tax assets 127.0 146.4
Deferred income tax liabilities:    
Property, plant and equipment (133.3) (142.6)
Lease liabilities (7.2) (8.7)
Undistributed foreign earnings (3.4) (3.0)
Total deferred income tax liabilities (143.9) (154.3)
Net deferred income tax liabilities $ (16.9) $ (7.9)
v3.25.0.1
Income Tax Matters - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 20, 2021
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Tax Credit Carryforward [Line Items]          
Increase (decrease) in valuation allowance   $ 2,800,000 $ (1,000,000)    
Global minimum tax rate 15.00%        
Gross unrecognized tax benefits   6,900,000 6,500,000 $ 5,000,000 $ 4,100,000
Amount that would be reflected in income tax provision if unrecognized tax benefits are recognized   6,900,000      
Accrued interest and penalties on unrecognized tax benefits   100,000 200,000    
Accrued interest and penalties on unrecognized tax benefits, current   0 $ 0    
(Decrease) increase in interest and penalties       $ 100,000  
Research Tax Credit Carryforward          
Tax Credit Carryforward [Line Items]          
Tax credit carryforward   $ 12,600,000      
Tax credit carryforward expiration period   Dec. 31, 2044      
State Tax Credit Carryforwards          
Tax Credit Carryforward [Line Items]          
Tax credit carryforward   $ 3,900,000      
Tax credit carryforward expiration period   Dec. 31, 2049      
v3.25.0.1
Income Tax Matters - Reconciliation of Changes in Gross Unrecognized Tax Benefits (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Income Tax Disclosure [Abstract]      
Gross unrecognized tax benefits at beginning of period $ 6.5 $ 5.0 $ 4.1
Gross increases for tax positions of current year 0.5 1.3 0.9
Gross increases for tax positions of prior years 0.0 0.2 0.1
Gross decreases for tax positions of prior years (0.1) 0.0 (0.1)
Gross unrecognized tax benefits at end of period $ 6.9 $ 6.5 $ 5.0
v3.25.0.1
Net Income (Loss) Per Share - Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Numerator:      
Net income (loss) $ 46.8 $ 47.2 $ (29.6)
Less: earnings attributable to participating securities [1]   (0.1)  
Net income (loss) available to common shareholders $ 46.8 $ 47.1 $ (29.6)
Denominator – Weighted-average common shares outstanding (in thousands):      
Basic 16,069 15,991 15,906
Add: dilutive effect of non-vested common shares, restricted stock units and performance shares [2] 250 140  
Diluted 16,319 16,131 15,906
Net income (loss) per common share, Basic $ 2.91 $ 2.95 $ (1.86)
Net income (loss) per common share, Diluted $ 2.87 $ 2.92 $ (1.86)
[1] Represents distributed and undistributed earnings allocated to non-vested RSAs that contain non-forfeitable rights to dividends.
[2] Quantities in the following discussion are denoted in whole shares. For the years ended December 31, 2024 and December 31, 2023, approximately 1,100 and 35,000 shares, respectively, were excluded from the weighted-average diluted shares computation as their inclusion would have been anti-dilutive. For the year ended December 31, 2022, approximately 139,000 potentially dilutive shares were excluded from the computation of net loss per share as their effect would have been anti‑dilutive.
v3.25.0.1
Net Income (Loss) Per Share - Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share (Parenthetical) (Details) - shares
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Earnings Per Share [Abstract]      
Antidilutive securities excluded from computation of earnings per share, amount 1,100 35,000 139,000
v3.25.0.1
Supplemental Cash Flow Information - Schedule of Supplemental Cash Flow Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Supplemental Cash Flow Elements [Abstract]        
Interest paid $ 40.5 $ 43.8 $ 45.7  
Non-cash investing and financing activities (included in Accounts payable):        
Unpaid purchases of property and equipment 19.6 19.3 28.9  
Supplemental lease disclosures:        
Operating lease liabilities arising from obtaining operating lease assets 2.6 3.2 3.1  
Cash paid for amounts included in the measurement of operating lease liabilities 8.2 9.3 9.8  
Finance lease liabilities arising from obtaining finance lease assets 2.9 10.0 1.0  
Components of cash, cash equivalents and restricted cash:        
Cash and cash equivalents 18.4 82.4 57.4  
Restricted cash included in Other assets 19.5 18.3 13.9  
Total cash, cash equivalents and restricted cash presented on our Statements of Consolidated Cash Flows $ 37.9 $ 100.7 $ 71.3 $ 317.0
v3.25.0.1
Business, Product and Geographical Area Information and Concentration of Risk - Additional Information (Details)
$ in Millions
 1 Months Ended 12 Months Ended
Feb. 20, 2025
Dec. 31, 2024
USD ($)
Customer
Dec. 31, 2023
Customer
Dec. 31, 2022
USD ($)
Customer
Segment Reporting Information [Line Items]        
Foreign currency transaction loss | $   $ 0.3   $ 0.5
Subsequent Event        
Segment Reporting Information [Line Items]        
Collective bargaining agreements expiring year 2025      
Collective bargaining agreements renewed expiring date 2030-09      
Workforce Subject to Collective Bargaining Arrangements | Customer Concentration Risk | Employee One        
Segment Reporting Information [Line Items]        
Concentration risk, percentage   65.00%    
Workforce Subject to Collective Bargaining Arrangements Expiring within One Year | Subsequent Event | Customer Concentration Risk | Employee Two        
Segment Reporting Information [Line Items]        
Concentration risk, percentage 39.00%      
Net sales | Customer Concentration Risk | Largest Customer        
Segment Reporting Information [Line Items]        
Concentration risk, percentage   16.00% 18.00% 19.00%
Number of customers | Customer   1 1 1
Net sales | Customer Concentration Risk | Second Largest Customer        
Segment Reporting Information [Line Items]        
Concentration risk, percentage   15.00% 16.00% 14.00%
Trade receivables | Customer Concentration Risk | Largest Customer        
Segment Reporting Information [Line Items]        
Concentration risk, percentage   17.00% 20.00%  
Trade receivables | Customer Concentration Risk | Second Largest Customer        
Segment Reporting Information [Line Items]        
Concentration risk, percentage   17.00% 13.00%  
Trade receivables | Customer Concentration Risk | Third Largest Customer        
Segment Reporting Information [Line Items]        
Concentration risk, percentage   15.00% 12.00%  
v3.25.0.1
Business, Product and Geographical Area Information and Concentration of Risk - Schedule of Significant Segment Expenses Provided To CODM (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Segment Reporting Information [Line Items]      
Net sales $ 3,024.0 $ 3,087.0 $ 3,427.9
Cost of products sold, excluding depreciation and amortization 2,691.1 2,754.9 3,180.2
Hedged cost of alloyed metal 1,567.8 1,621.1 2,045.2
Manufacturing costs 805.2 809.9 773.0
Plant overhead 170.5 164.6 162.3
Freight costs 91.6 103.3 125.5
Other cost of products sold 56.0 56.0 74.2
Depreciation and amortization 116.4 108.6 106.9
Selling, general, administrative, research and development 120.8 122.7 110.9
Research and development costs 2.2 2.9 1.9
Employee costs 83.3 80.0 69.9
Other selling, general and administrative costs 35.3 39.8 39.1
Goodwill impairment 0.0 0.0 20.5
Restructuring costs 7.6 5.0 2.2
Other operating charges, net 0.4 0.0 3.2
Interest expense 43.7 46.9 48.3
Other income, net - Note 13 (19.5) (7.4) (6.4)
Income tax provision (benefit) 16.7 9.1 (8.3)
Net income (loss) $ 46.8 $ 47.2 $ (29.6)
v3.25.0.1
Business, Product and Geographical Area Information and Concentration of Risk - Schedule of Significant Segment Expenses Provided To CODM (Parenthetical) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Segment Reporting Information [Line Items]      
Hedged cost realized losses upon settlement $ 0.2 $ 21.4 $ 17.0
v3.25.0.1
Business, Product and Geographical Area Information and Concentration of Risk - Schedule of Net Sales by End Market Segment Applications (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Net sales:      
Net sales $ 3,024.0 $ 3,087.0 $ 3,427.9
Aero/HS Products      
Net sales:      
Net sales 883.0 899.3 676.1
Packaging      
Net sales:      
Net sales 1,260.9 1,315.2 1,585.3
Automotive Extrusions      
Net sales:      
Net sales 251.9 254.9 254.8
GE Products      
Net sales:      
Net sales 618.1 596.5 883.8
Other Products      
Net sales:      
Net sales 10.1 21.1 27.9
Products Transferred at a Point in Time      
Net sales:      
Net sales 2,326.5 2,394.8 2,782.9
Products Transferred Over Time      
Net sales:      
Net sales $ 697.5 $ 692.2 $ 645.0
v3.25.0.1
Business, Product and Geographical Area Information and Concentration of Risk - Schedule of Net Sales, Income Taxes Paid, and Long-lived Assets, by Geographical Area (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Revenues From External Customers And Long Lived Assets [Line Items]      
Net sales $ 3,024.0 $ 3,087.0 $ 3,427.9
Income taxes paid 4.4 0.5 6.3
Long-lived assets 1,161.2 1,052.1 1,013.2
Domestic      
Revenues From External Customers And Long Lived Assets [Line Items]      
Net sales 2,920.0 2,986.0 3,328.2
Income taxes paid 1.3 0.3 3.1
Long-lived assets 1,134.5 1,025.3 984.8
Foreign      
Revenues From External Customers And Long Lived Assets [Line Items]      
Net sales 104.0 101.0 99.7
Income taxes paid 3.1 0.2 3.2
Long-lived assets $ 26.7 $ 26.8 $ 28.4
v3.25.0.1
Business, Product and Geographical Area Information and Concentration of Risk - Schedule of Export Sales and Primary Aluminum Supply from Major Suppliers (Details)
 12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Export Sales | Geographic Concentration Risk | Supplier      
Concentration Risk [Line Items]      
Concentration risk, percentage 10.00% 10.00% 10.00%
Aluminum | Supplier Concentration Risk | Top Five Major Suppliers      
Concentration Risk [Line Items]      
Concentration risk, percentage 80.00% 83.00% 81.00%
Aluminum | Supplier Concentration Risk | Largest Supplier      
Concentration Risk [Line Items]      
Concentration risk, percentage 21.00% 37.00% 48.00%
Aluminum | Supplier Concentration Risk | Second and Third Largest Suppliers      
Concentration Risk [Line Items]      
Concentration risk, percentage 38.00% 28.00% 20.00%
v3.25.0.1
Subsequent Events - Additional Information (Details)
$ / shares in Units, $ in Millions
 1 Months Ended 12 Months Ended
Jan. 14, 2025
USD ($)
$ / shares
Feb. 20, 2025
Employee
Dec. 31, 2024
$ / shares
Dec. 31, 2023
$ / shares
Dec. 31, 2022
$ / shares
Subsequent Event [Line Items]          
Cash dividends declared (in dollars per share)     $ 3.08 $ 3.08 $ 3.08
Subsequent Event          
Subsequent Event [Line Items]          
Multiemployer plans collective bargaining arrangement number of employees located at facility | Employee   1,000      
O 2024 Q4 Dividends | Subsequent Event          
Subsequent Event [Line Items]          
Cash dividends declared (in dollars per share) $ 0.77        
Cash dividends declared | $ $ 12.7        
Cash dividends, declared date Jan. 14, 2025        
Cash dividends, payable date Feb. 14, 2025        
Cash dividends, record date Jan. 24, 2025