Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2025	Feb. 20, 2026	Jun. 30, 2025
Document information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2025
Securities Act File Number	001-38492
Entity Registrant Name	Kiniksa Pharmaceuticals International, plc
Entity Incorporation, State or Country Code	X0
Entity Tax Identification Number	98-1795578
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 Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Error correction flag	false
Auditor Name	PricewaterhouseCoopers LLP
Auditor Firm ID	238
Auditor Location	Boston, Massachusetts
Entity Shell Company	false
Entity Public Float			$ 1,114.0
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Entity Central Index Key	0001730430
Amendment Flag	false
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement for its 2026 Annual Meeting of Shareholders, which the registrant intends to file with the Securities and Exchange Commission pursuant to Regulation 14A within 120 days after the end of the registrant’s fiscal year ended December 31, 2025, are incorporated by reference into Part III of this Annual Report on Form 10-K.
Ordinary Shares
Document information
Entity Common Stock, Shares Outstanding		76,535,377
Class A ordinary shares
Document information
Entity Common Stock, Shares Outstanding		45,900,637
Class B ordinary shares
Document information
Entity Common Stock, Shares Outstanding		1,795,158
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

Kiniksa Pharmaceuticals International, plc 10-K