Schedule I - Financial Information of the Registrant (Parent Company) - Statements of Income and Retained Earnings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Expenses
Interest	$ 19,737	$ 18,403	$ 5,031
Other operating expenses	507,701	648,022	626,762
Total expenses	2,196,480	2,836,644	2,871,821
Income tax expense	(15,263)	(50,864)	(93,989)
Net income attributable to Stewart	30,439	162,305	323,216
Retained Earnings [Roll Forward]
Retained earnings at beginning of year	1,091,816
Cash dividends on Common Stock	(51,414)	(45,289)	(37,235)
Retained earnings at end of year	1,070,841	1,091,816
Parent company
Revenues
Net realized losses, net of interest and other income	(2,222)	(1,639)	(281)
Expenses
Interest	18,402	18,276	5,101
Other operating expenses	8,440	8,161	6,924
Total expenses	26,842	26,437	12,025
Loss before taxes and income from investments in subsidiaries	(29,064)	(28,076)	(12,306)
Income tax expense	(28)	(8)	0
Income from investments in subsidiaries	59,531	190,389	335,522
Net income attributable to Stewart	30,439	162,305	323,216
Retained Earnings [Roll Forward]
Retained earnings at beginning of year	1,091,816	974,800	688,819
Cash dividends on Common Stock	(51,414)	(45,289)	(37,235)
Retained earnings at end of year	$ 1,070,841	$ 1,091,816	$ 974,800