Earnings per share - Calculation of Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Numerator:
Net earnings attributable to Stewart	$ 23,717	$ 15,409	$ 17,890	$ 45,514
Interest expense, net of tax effects	314	303	941	1,109
If-converted net earnings attributable to Stewart	$ 24,031	$ 15,712	$ 18,831	$ 46,623
Denominator:
Basic average shares outstanding	22,267	22,475	22,416	21,962
Dilutive average number of shares	2,111	2,115	2,111	2,595
Diluted average shares outstanding	24,663	24,769	24,812	24,735
Basic earnings per share attributable to Stewart (usd per share)	$ 1.07	$ 0.69	$ 0.80	$ 2.07
Diluted earnings per share attributable to Stewart (usd per share)	$ 0.97	$ 0.63	$ 0.76	$ 1.88
Options
Denominator:
Dilutive average number of shares	1	1	1	0
Restricted Shares
Denominator:
Dilutive average number of shares	284	178	284	178