v3.26.1
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2026
Jul. 24, 2026
Document information    
Document Type 10-Q  
Document Quarterly Report true  
Document Transition Report false  
Document Period End Date Jun. 30, 2026  
Securities Act File Number 001-38492  
Entity Registrant Name Kiniksa Pharmaceuticals International, plc  
Entity Incorporation, State or Country Code X0  
Entity Tax Identification Number 00-0000000  
Entity Address, Address Line One 105 Piccadilly, Second Floor  
Entity Address, City or Town London  
Entity Address, Country GB  
Entity Address, Postal Zip Code W1J 7NJ  
City Area Code 781  
Local Phone Number 431-9100  
Title of 12(b) Security Class A Ordinary Shares  
Trading Symbol KNSA  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q2  
Entity Central Index Key 0001730430  
Amendment Flag false  
Ordinary Shares    
Document information    
Entity Common Stock, Shares Outstanding   78,024,013
Class A ordinary shares    
Document information    
Entity Common Stock, Shares Outstanding   48,289,273
Class B ordinary shares    
Document information    
Entity Common Stock, Shares Outstanding   895,158
Class A1 ordinary shares    
Document information    
Entity Common Stock, Shares Outstanding   12,781,964
Class B1 ordinary shares    
Document information    
Entity Common Stock, Shares Outstanding   16,057,618