Schedule I - Statements of Operations and Retained Earnings (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues
Investment income									$ 16,806	$ 15,492	$ 13,809
Other losses									6,744	(1,066)	7,578
Total revenues	522,319	508,097	446,838	393,576	450,211	536,835	517,220	423,714	1,870,830	1,927,980	1,910,412
Expenses
Employee costs									624,326	571,026	542,461
Other operating expenses, including $276, $276 and $305 to affiliates									347,276	280,258	286,496
Depreciation and amortization									24,226	17,920	17,783
Interest									3,236	2,956	5,235
Total expenses									1,819,018	1,826,915	1,821,074
Earnings (loss) before taxes and earnings from subsidiaries									51,812	101,065	89,338
Income tax expense									(13,503)	(28,481)	29,639
Net earnings attributable to Stewart	11,863	23,717	6,279	(12,106)	17,511	15,409	26,899	3,207	29,753	63,026	109,182
Retained earnings at beginning of year				452,314					452,314
Cash dividends on Common Stock ($0.10 per share)									(2,334)	(2,159)	(1,832)
Retained earnings at end of year	479,733				452,314				479,733	452,314
Stewart Information Services Corporation - Parent Company
Revenues
Investment income									25,087	0	579
Other losses									(869)	(3,164)	(3,358)
Other income									90	263	380
Total revenues									24,308	(2,901)	(2,399)
Expenses
Employee costs									1,110	(91)	5,192
Other operating expenses, including $276, $276 and $305 to affiliates									3,806	1,329	1,674
Depreciation and amortization									421	527	802
Interest									2,054	2,494	4,615
Total expenses									7,391	4,259	12,283
Earnings (loss) before taxes and earnings from subsidiaries									16,917	(7,160)	(14,682)
Income tax expense									(1)	(24)	(34)
Add earnings from subsidiaries									12,837	70,210	123,898
Net earnings attributable to Stewart									29,753	63,026	109,182
Retained earnings at beginning of year				452,314				391,447	452,314	391,447	284,097
Cash dividends on Common Stock ($0.10 per share)									(2,334)	(2,159)	(1,832)
Retained earnings at end of year	$ 479,733				$ 452,314				$ 479,733	$ 452,314	$ 391,447