v3.26.1
Cover - shares
 6 Months Ended
Jun. 30, 2026
Aug. 13, 2026
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2026  
Document Transition Report false  
Entity File Number 001-43328  
Registrant Name Quantinuum Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 41-4095842  
Entity Address, Address Line One 303 S Technology Court  
Entity Address, City or Town Broomfield  
Entity Address, State or Province CO  
Entity Address, Postal Zip Code 80021  
City Area Code 855  
Local Phone Number 888-7686  
Title of 12(b) Security Class A common stock, par value $0.0001 per share  
Trading Symbol QNT  
Security Exchange Name NASDAQ  
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 false  
Amendment Flag false  
Document Fiscal Period Focus Q2  
Document Fiscal Year Focus 2026  
Current Fiscal Year End Date --12-31  
Central Index Key 0002110105  
Class A    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   36,893,857
Class B    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   226,414,285