Document and Entity Information - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Feb. 23, 2016	Jun. 30, 2015
Document Information [Line Items]
Entity Registrant Name	STEWART INFORMATION SERVICES CORP
Entity Central Index Key	0000094344
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY
Trading Symbol	STC
Amendment Flag	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 884,240
Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		22,292,100
Class B Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		1,050,012