v3.26.1
Document And Entity Information - shares
 6 Months Ended
Jun. 30, 2026
Aug. 17, 2026
Document Information Line Items    
Entity Central Index Key 0002123471  
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2026  
Document Fiscal Year Focus 2026  
Document Transition Report false  
Entity File Number 001-43390  
Entity Registrant Name Columbus Circle Capital Corp III  
Entity Incorporation, State or Country Code E9  
Entity Tax Identification Number 00-0000000  
Entity Address, Address Line One 3 Columbus Circle, 24th Floor  
Entity Address, City or Town New York  
Entity Address, State or Province NY  
Entity Address, Postal Zip Code 10019  
City Area Code 646  
Local Phone Number 792-5600  
Entity Current Reporting Status No  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Shell Company true  
Amendment Flag false  
Document Fiscal Period Focus Q2  
Current Fiscal Year End Date --12-31  
Units, each consisting of one Class A Ordinary Share and one-third of one redeemable Warrant    
Document Information Line Items    
Title of 12(b) Security Units, each consisting of one Class A Ordinary Share and one-third of one redeemable Warrant  
Trading Symbol CCCTU  
Security Exchange Name NASDAQ  
Class A Ordinary Shares, par value $0.0001 per share    
Document Information Line Items    
Title of 12(b) Security Class A Ordinary Shares, par value $0.0001 per share  
Trading Symbol CCCT  
Security Exchange Name NASDAQ  
Redeemable Warrants, each whole Warrant exercisable for one Class A Ordinary Share at an exercise price of $11.50 per share    
Document Information Line Items    
Title of 12(b) Security Redeemable Warrants, each whole Warrant exercisable for one Class A Ordinary Share at an exercise price of $11.50 per share  
Trading Symbol CCCTW  
Security Exchange Name NASDAQ  
Class A Ordinary Shares    
Document Information Line Items    
Entity Common Stock, Shares Outstanding   23,665,000
Class B Ordinary Shares    
Document Information Line Items    
Entity Common Stock, Shares Outstanding   7,666,667