v3.26.1
Document and Entity Information - USD ($)
12 Months Ended
May 31, 2026
Jul. 24, 2026
Nov. 28, 2025
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date May 31, 2026    
Document Fiscal Year Focus 2026    
Document Fiscal Period Focus FY    
Trading Symbol WS    
Entity Registrant Name WORTHINGTON STEEL, INC.    
Entity Central Index Key 0001968487    
Current Fiscal Year End Date --05-31    
Entity Well-known Seasoned Issuer Yes    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Large Accelerated Filer    
Entity Interactive Data Current Yes    
Entity Shell Company false    
Entity Small Business false    
Entity Emerging Growth Company false    
Title of 12(b) Security Common Shares, Without Par Value    
Security Exchange Name NYSE    
Entity Common Stock, Shares Outstanding   50,948,146  
Entity Public Float     $ 1,116,545,985
Entity File Number 001-41830    
Entity Incorporation, State or Country Code OH    
Entity Tax Identification Number 92-2632000    
Entity Address, Address Line One 100 West Old Wilson Bridge Road    
Entity Address, City or Town Columbus    
Entity Address, State or Province OH    
Entity Address, Postal Zip Code 43085    
City Area Code 614    
Local Phone Number 840-3462    
Document Annual Report true    
Document Transition Report false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction [Flag] false    
Documents Incorporated by Reference

DOCUMENTS INCORPORATED BY REFERENCE:

Selected portions of the registrant’s definitive proxy statement for its annual meeting of shareholders to be held on September 23, 2026 (the “2026 Proxy Statement”), are incorporated by reference into Part III of this annual report on Form 10-K to the extent provided herein.

   
Auditor Name KPMG LLP    
Auditor Location Detroit, Michigan    
Auditor Firm ID 185    
Auditor Opinion [Text Block]

Opinion on the Consolidated and Combined Financial Statements

We have audited the accompanying consolidated balance sheets of Worthington Steel, Inc. and subsidiaries (the Company) as of May 31, 2026 and 2025, the related consolidated and combined statements of earnings, comprehensive income, equity and mezzanine equity, and cash flows for each of the years in the three-year period ended May 31, 2026, and the related notes and financial statement schedule II (collectively, the consolidated and combined financial statements). In our opinion, the consolidated and combined financial statements present fairly, in all material respects, the financial position of the Company as of May 31, 2026 and 2025, and the results of its operations and its cash flows for each of the years in the three-year period ended May 31, 2026, in conformity with U.S. generally accepted accounting principles.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company’s internal control over financial reporting as of May 31, 2026, based on criteria established in Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission, and our report dated July 30, 2026 expressed an unqualified opinion on the effectiveness of the Company’s internal control over financial reporting.