v3.25.2
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2025
Jul. 25, 2025
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Quarterly Report true  
Document Transition Report false  
Document Period End Date Jun. 30, 2025  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Entity Registrant Name RYERSON HOLDING CORPORATION  
Entity Central Index Key 0001481582  
Current Fiscal Year End Date --12-31  
Entity Filer Category Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   32,198,906
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity File Number 001-34735  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 26-1251524  
Entity Address, Address Line One 227 W. Monroe St.  
Entity Address, Address Line Two 27th Floor  
Entity Address, City or Town Chicago  
Entity Address, State or Province IL  
Entity Address, Postal Zip Code 60606  
City Area Code 312  
Local Phone Number 292-5000  
Title of 12(b) Security Common Stock, $0.01 par value, 100,000,000 shares authorized  
Trading Symbol RYI  
Security Exchange Name NYSE