Document And Entity Information - USD ($)	12 Months Ended
Document And Entity Information - USD ($)	Dec. 31, 2024	Mar. 18, 2025	Jun. 28, 2024
Document Information [Line Items]
Entity Central Index Key	0001626878
Entity Registrant Name	XBiotech Inc.
Amendment Flag	true
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2024
Document Type	10-K/A
Amendment Description	This Amendment No. 1 (this “Amendment”) amends the Annual Report on Form 10-K for the year ended December 31, 2024 of XBiotech, Inc. (the “Company”), filed with the Securities and Exchange Commission (the “SEC”) on March 18, 2025 (the “Original Form 10-K”). The purpose of this Amendment is solely to amend Part III, Items 10 through 14 of the Original Form 10-K to include information previously omitted from the Original Form 10-K in reliance on General Instruction G(3) to Form 10-K which permits the above-referenced Items to be incorporated in the Annual Report on Form 10-K by reference from a definitive proxy statement, if such proxy statement is filed no later than 120 days after December 31, 2024. At this time, the Company is filing this Amendment to include Part III information in our Annual Report on Form 10-K because we do not intend to file a definitive proxy statement within 120 days of December 31, 2024. Accordingly, Part III of the Original Form 10-K is hereby amended and restated as set forth herein. The information included herein as required by Part III, Items 10 through 14 of Form 10-K is more limited than what is required to be included in the definitive proxy statement to be filed in connection with our annual meeting of stockholders. Accordingly, the definitive proxy statement to be filed at a later date will include additional information related to the topics herein and additional information not required by Part III, Items 10 through 14 of Form 10-K. The reference on the cover page of the Original Form 10-K to the incorporation by reference of our definitive proxy statement into Part III of the Original Form 10-K is hereby deleted. Except as stated herein, this Amendment does not reflect events occurring after the filing of the Original Form 10-K and no attempt has been made in this Amendment to modify or update other disclosures as presented in the Original Form 10-K.
Document Annual Report	true
Document Period End Date	Dec. 31, 2024
Document Transition Report	false
Entity File Number	001-37437
Entity Incorporation, State or Country Code	A1
Entity Address, Address Line One	5217 Winnebago Ln
Entity Address, City or Town	Austin
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78744
City Area Code	512
Local Phone Number	386-2900
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	XBIT
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 121,869,724
Entity Common Stock, Shares Outstanding		30,487,731

XBiotech Inc. 10-K/A