Schedule I - Statements of Operations and Retained Earnings (Parenthetical) (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Condensed Consolidating Statement of Operations [Line Items]
Investment income	$ 13,809	$ 15,505	$ 18,397
Other operating expenses	286,496	256,194	273,253
Stewart Information Services Corporation - Parent Company
Schedule of Condensed Consolidating Statement of Operations [Line Items]
Investment income	579	74	86
Other operating expenses	1,674	451	5,796
Cash dividends on Common Stock, per share	$ 0.10	$ 0.05	$ 0.05
Affiliates | Stewart Information Services Corporation - Parent Company
Schedule of Condensed Consolidating Statement of Operations [Line Items]
Investment income	0	0	22
Other operating expenses	$ 305	$ 177	$ 144