Schedule I - Parent Company Financial Information - Statements of Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of net earnings to cash used by operating activities:
Net (loss) income	$ 2,605	$ (13,467)	$ 17,106	$ (12,448)	$ 11,863	$ 23,717	$ 6,279	$ (12,106)	$ (6,204)	$ 29,753	$ 63,026
Add (deduct):
Depreciation and amortization									30,298	24,226	17,920
Other losses									1,369	(6,744)	1,066
Increase in receivables – net									13,267	9,397	(5,796)
(Increase) decrease in other assets – net									3,073	(1,878)	(1,467)
Increase in payables and accrued liabilities – net									2,088	(6,854)	(8,100)
Losses (income) from subsidiaries									(3,579)	(3,442)	(4,137)
Other – net									5,668	448	281
Cash provided by operating activities									80,514	63,989	87,187
Investing activities:
Collections on notes receivables									1,302	386	2,666
Cash used by investing activities									(68,791)	(78,557)	(78,363)
Financing activities:
Proceeds from notes payable									52,651	120,273	11,146
Payments on notes payable									(22,494)	(60,838)	(12,199)
Repurchases of Common Stock									(27,950)	(22,048)	0
Other – net									168	(21)	48
Cash (used) provided by financing activities									(25,550)	26,026	(18,196)
(Decrease) increase in cash and cash equivalents									(21,491)	6,269	(14,249)
Cash and cash equivalents at beginning of year				200,558				194,289	200,558	194,289	208,538
Cash and cash equivalents at end of year	179,067				200,558				179,067	200,558	194,289
Supplemental information:
Income taxes paid									14,982	(106)	18,032
Interest paid									1,873	2,616	2,202
Stewart Information Services Corporation - Parent Company
Reconciliation of net earnings to cash used by operating activities:
Net (loss) income									(6,204)	29,753	63,026
Add (deduct):
Depreciation and amortization									162	421	527
Other losses									0	869	3,164
Increase in receivables – net									(22,096)	(47,232)	(95)
(Increase) decrease in other assets – net									(558)	(828)	2,413
Increase in payables and accrued liabilities – net									21,136	12,395	3,335
Losses (income) from subsidiaries									12,465	(12,837)	(70,210)
Other – net									(26,244)	(31,824)	(3,945)
Cash provided by operating activities									(21,339)	(49,283)	(1,785)
Investing activities:
Dividends from subsidiaries									15,000	25,000	0
Proceeds from the sale of property and equipment –net									0	0	5
Collections on notes receivables									0	0	1
Cash used by investing activities									15,000	25,000	6
Financing activities:
Proceeds from notes payable									45,000	60,000	0
Payments on notes payable									(7,000)	0	0
Dividends paid									(18,010)	(2,334)	(2,159)
Repurchases of Common Stock									(27,950)	(22,048)	0
Purchase of remaining interest of consolidated subsidiary									(209)	(321)	(1,442)
Settlement of convertible debt									0	0	(1,149)
Other – net									130	0	0
Cash (used) provided by financing activities									(8,039)	35,297	(4,750)
(Decrease) increase in cash and cash equivalents									(14,378)	11,014	(6,529)
Cash and cash equivalents at beginning of year				$ 15,210				$ 4,196	15,210	4,196	10,725
Cash and cash equivalents at end of year	$ 832				$ 15,210				832	15,210	4,196
Supplemental information:
Income taxes paid									1	24	34
Interest paid									$ 1,681	$ 546	$ 4