Earnings per share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net income (loss) attributable to Stewart	$ 5,177	$ (6,766)
Denominator (000):
Basic average shares outstanding (in shares)	23,638	23,595
Basic and diluted average shares outstanding (in shares)	23,749	23,595
Basic earnings per share attribute to Stewart (in usd per share)	$ 0.22	$ (0.29)
Diluted earnings per share attribute to Stewart (in usd per share)	$ 0.22	$ (0.29)
Restricted Stock And Restricted Stock Units
Denominator (000):
Average number of dilutive shares relating to grants of share-based arrangements	111	0