v3.26.1
Long-Term Debt - Long-Term Debt (Detail) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Debt Instrument [Line Items]    
Unamortized debt issuance costs $ (9.4) $ (2.0)
Total debt 955.2 463.1
Less: Short-term foreign debt 2.6 1.9
Total long-term debt 952.6 461.2
Ryerson Credit Facility [Member]    
Debt Instrument [Line Items]    
Ryerson Credit Facility 962.0 463.2
Foreign Debt [Member]    
Debt Instrument [Line Items]    
Foreign debt $ 2.6 $ 1.9