Schedule I - Balance Sheets (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Other	$ 56,311,000	$ 39,660,000
Accounts payable and accrued liabilities	116,617,000	86,389,000
Treasury stock, common shares	352,161	352,161
Stewart Information Services Corporation - Parent Company
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Other	43,000	476,000
Accounts payable and accrued liabilities	30,346,000	23,537,000
Treasury stock, common shares	352,161	352,161
Undistributed earnings of subsidiaries	466,442	344,376
Common Stock
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Common Stock, par value	$ 1	$ 1
Common stock, shares authorized	50,000,000	50,000,000
Common Stock, shares issued	18,705,914	18,605,993
Common Stock, shares outstanding	18,353,753	18,253,832
Common Stock | Stewart Information Services Corporation - Parent Company
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Common Stock, par value	$ 1	$ 1
Common stock, shares authorized	50,000,000	50,000,000
Common Stock, shares issued	18,705,914	18,605,993
Common Stock, shares outstanding	18,353,753	18,253,832
Class B Common Stock
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Common Stock, par value	$ 1	$ 1
Common stock, shares authorized	1,500,000	1,500,000
Common Stock, shares issued	1,050,012	1,050,012
Common Stock, shares outstanding	1,050,012	1,050,012
Class B Common Stock | Stewart Information Services Corporation - Parent Company
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Common Stock, par value	$ 1	$ 1
Common stock, shares authorized	1,500,000	1,500,000
Common Stock, shares issued	1,050,012	1,050,012
Common Stock, shares outstanding	1,050,012	1,050,012
Affiliates | Stewart Information Services Corporation - Parent Company
Schedule of Condensed Consolidating Balance Sheets [Line Items]
Other	3,000	191,000
Accounts payable and accrued liabilities	$ 3,000	$ 104,000