Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2022	Feb. 17, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-02658
Entity Registrant Name	STEWART INFORMATION SERVICES CORP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	74-1677330
Entity Address, Address Line One	1360 Post Oak Blvd.,
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Houston,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77056
City Area Code	713
Local Phone Number	625-8100
Title of 12(b) Security	Common Stock, $1 par value per share
Trading Symbol	STC
Security Exchange Name	NYSE
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
Entity Shell Company	false
Entity Public Float			$ 1.3
Entity Common Stock, Shares Outstanding		27,193,457
Documents Incorporated by Reference	Portions of the definitive proxy statement (the Proxy Statement), in connection with the Registrant's 2023 Annual Meeting of Stockholders, are incorporated herein by reference in Part III of this document.
Entity Central Index Key	0000094344
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false