Schedule I - Statements of Operations and Retained Earnings (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended											12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Revenues
Investment income, including $0, $0 and $22 from affiliates												$ 13,809		$ 15,505		$ 18,397
Other (losses) gains												7,578		2,302		21,782
Total revenues	520,972		520,741	483,712	384,987		445,077		418,529	404,883	366,417	1,910,412		1,634,906		1,672,390
Expenses
Employee costs												542,461		469,839		467,491
Other operating expenses, including $305, $177 and $144 to affiliates												286,496		256,194		273,253
Depreciation and amortization												17,783		19,542		21,422
Interest												5,235		5,268		5,423
Total expenses												1,821,074		1,616,887		1,669,465
Loss before tax expense (benefit) and loss from subsidiaries												89,338		18,019		2,925
Income tax expense (benefit)												29,639		(9,341)		(8,075)
Net earnings (loss) attributable to Stewart	61,760		34,668	24,911	(12,157)		2,159		4,542	5,940	(10,293)	109,182		2,348		(12,582)
Retained earnings at beginning of year					284,097							284,097
Retained earnings at end of year	391,447						284,097					391,447		284,097
Stewart Information Services Corporation - Parent Company
Revenues
Investment income, including $0, $0 and $22 from affiliates												579		74		86
Other (losses) gains												(3,358)		(3,770)		3,109
Other income												380		235		68
Total revenues												(2,399)		(3,461)		3,263
Expenses
Employee costs												5,192		2,168		1,388
Other operating expenses, including $305, $177 and $144 to affiliates												1,674		451		5,796
Depreciation and amortization												802		893		862
Interest												4,615		4,639		4,658
Total expenses												12,283		8,151		12,704
Loss before tax expense (benefit) and loss from subsidiaries												(14,682)		(11,612)		(9,441)
Income tax expense (benefit)												34		79		(277)
Less (earnings) loss from subsidiaries												(123,898)		(14,039)		3,418
Net earnings (loss) attributable to Stewart												109,182		2,348		(12,582)
Retained earnings at beginning of year					284,097	[1]					282,666	284,097	[1]	282,666		296,116
Cash dividends on Common Stock ($0.10 per share in 2012 and $0.05 per share in 2011 and 2010)												(1,832)		(917)		(868)
Retained earnings at end of year	$ 391,447	[1]					$ 284,097	[1]				$ 391,447	[1]	$ 284,097	[1]	$ 282,666

[1] Includes undistributed earnings of subsidiaries of $466,442 in 2012 and $344,376 in 2011.