Changes in Stockholders' Equity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 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	Dec. 31, 2012 Common and Class B Common Stock	Dec. 31, 2011 Common and Class B Common Stock	Dec. 31, 2010 Common and Class B Common Stock	Dec. 31, 2012 Additional paid-in capital	Dec. 31, 2011 Additional paid-in capital	Dec. 31, 2010 Additional paid-in capital	Dec. 31, 2012 Accumulated other comprehensive earnings	Dec. 31, 2011 Accumulated other comprehensive earnings	Dec. 31, 2010 Accumulated other comprehensive earnings	Dec. 31, 2012 Retained Earnings	Dec. 31, 2011 Retained Earnings	Dec. 31, 2010 Retained Earnings	Dec. 31, 2011 Treasury stock	Dec. 31, 2012 Treasury stock	Dec. 31, 2009 Treasury stock	Dec. 31, 2012 Noncontrolling interests	Dec. 31, 2011 Noncontrolling interests	Dec. 31, 2010 Noncontrolling interests
Equity Note [Line Items]
Beginning balance				$ 463,457					$ 463,457			$ 19,656	$ 18,851	$ 18,708	$ 132,446	$ 124,413	$ 126,822	$ 16,681	$ 13,610	$ 10,960	$ 284,097	$ 282,666	$ 296,116	$ (4,330)	$ (2,666)	$ (4,330)	$ 13,243	$ 13,123	$ 13,790
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)										109,182	2,348	(12,582)
Cash dividends on common stock ($0.10 in 2012, and $0.05 in 2011 and 2010)																					(1,832)	(917)	(868)
Stock bonuses and other												50	169	143	935	1,452	1,284
Exercise of stock options												50			1,044
Settlement of wage and hour litigation through issuance of Common Stock													636			6,946
Purchase of remaining interest of consolidated subsidiary															(740)		(3,693)												(506)
Settlement of note payable through issuance of Common Stock held in treasury																(365)								1,664
Provision for Canadian taxes																				(1,185)
Net change in unrealized gains and losses on investments																		9,240	7,245	1,448
Net realized gain reclassification																		(2,256)	(2,331)	(1,142)
Foreign currency translation																		2,919	(1,843)	3,529
Net earnings attributable to noncontrolling interests									(9,795)	(6,330)	(7,432)																9,795	6,330	7,432
Subsidiary dividends paid to noncontrolling interests																											(9,512)	(6,142)	(7,122)
Net effect of changes in ownership and other																											(1,960)	(68)	(471)
Ending balance	$ 580,372				$ 463,457				$ 580,372	$ 463,457		$ 19,756	$ 19,656	$ 18,851	$ 133,685	$ 132,446	$ 124,413	$ 26,584	$ 16,681	$ 13,610	$ 391,447	$ 284,097	$ 282,666	$ (2,666)	$ (2,666)	$ (4,330)	$ 11,566	$ 13,243	$ 13,123