v3.26.1
Investments - Additional Information (Detail)
$ in Millions
12 Months Ended
May 31, 2026
USD ($)
Jointventure
May 31, 2025
USD ($)
May 31, 2024
USD ($)
Investments in and Advances to Affiliates [Line Items]      
Assets, Fair Value Disclosure $ 76.8    
Serviacero Worthington      
Investments in and Advances to Affiliates [Line Items]      
Percent of ownership own a noncontrolling interest held in unconsolidated joint venture 50.00%    
Number of unconsolidated joint ventures | Jointventure 1    
Distributions from unconsolidated affiliates $ 23.5 $ 12.8 $ 2.0
Consolidated retained earnings undistributed earnings net of tax 61.7 $ 64.9  
Kloeckner      
Investments in and Advances to Affiliates [Line Items]      
Dividend income $ 1.9