v3.26.3
Investments - Schedule of Financial Information of Unconsolidated Affiliates (Detail) - USD ($)
 3 Months Ended
Aug. 31, 2026
Aug. 31, 2025
May 31, 2026
Investments in and Advances to Affiliates, Activity [Line Items]      
Cash and cash equivalents $ 248,200,000   $ 84,600,000
Total assets 6,021,900,000   2,252,400,000
Current liabilities 2,109,300,000   775,800,000
Other non-current liabilities 83,300,000   51,500,000
Equity 1,032,300,000   1,063,300,000
Total liabilities, mezzanine equity, and equity 6,021,900,000   2,252,400,000
Net sales 2,726,600,000 $ 872,900,000  
Gross margin 261,200,000 115,200,000  
Operating income 56,000,000 48,300,000  
Depreciation and amortization 27,800,000 20,300,000  
Interest expense 2,000,000 0  
Income tax expense 12,100,000 13,400,000  
Net earnings (5,000,000) 38,600,000  
Serviacero Worthington      
Investments in and Advances to Affiliates, Activity [Line Items]      
Cash and cash equivalents 52,800,000   24,300,000
Other current assets 220,700,000   221,800,000
Non-current assets 61,100,000   61,900,000
Total assets 334,600,000   308,000,000
Current liabilities 73,600,000   57,600,000
Other non-current liabilities 4,700,000   4,700,000
Equity 256,300,000   245,700,000
Total liabilities, mezzanine equity, and equity 334,600,000   $ 308,000,000
Net sales 134,000,000 134,200,000  
Gross margin 19,300,000 18,600,000  
Operating income 15,400,000 14,500,000  
Depreciation and amortization 1,000,000 1,000,000  
Interest expense 0 0  
Income tax expense 4,100,000 2,000,000  
Net earnings $ 10,700,000 $ 12,800,000