Earnings per share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator:
Net (loss) income attributable to Stewart	$ (3,780)	$ 4,087
Denominator (000):
Basic average shares outstanding	23,508	23,433
Average number of dilutive shares relating to grants of restricted shares and units	0	136
Diluted average shares outstanding	23,508	23,569
Basic (loss) earnings per share attributable to Stewart (in usd per share)	$ (0.16)	$ 0.17
Diluted (loss) earnings per share attributable to Stewart (in usd per share)	$ (0.16)	$ 0.17