CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Common Stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)	Treasury stock	Noncontrolling interests
Balances at beginning of period at Dec. 31, 2019	$ 753,759	$ 24,062	$ 164,217	$ 564,392	$ (2,699)	$ (2,666)	$ 6,453
Increase (Decrease) in Stockholders' Equity
Net income attributable to Stewart	95,232			95,232
Dividends on Common Stock	(22,401)			(22,401)
Issuance of Common Stock	108,961	3,026	105,935
Stock-based compensation	4,234	4	4,230
Stock repurchases	(826)	(20)	(806)
Change in net unrealized gains and losses on investments, net of taxes	15,055				15,055
Reclassification adjustment for realized gains and losses on investments, net of taxes	(276)				(276)
Foreign currency translation adjustments, net of taxes	(3,404)				(3,404)
Net income attributable to noncontrolling interests	10,107						10,107
Distributions to noncontrolling interests	(9,572)						(9,572)
Balances at end of period at Sep. 30, 2020	950,869	27,072	273,576	637,223	8,676	(2,666)	6,988
Balances at beginning of period at Jun. 30, 2020	787,332	24,052	166,208	589,424	4,087	(2,666)	6,227
Increase (Decrease) in Stockholders' Equity
Net income attributable to Stewart	55,909			55,909
Dividends on Common Stock	(8,110)			(8,110)
Issuance of Common Stock	108,961	3,026	105,935
Stock-based compensation	1,785	2	1,783
Stock repurchases	(358)	(8)	(350)
Change in net unrealized gains and losses on investments, net of taxes	920				920
Reclassification adjustment for realized gains and losses on investments, net of taxes	(175)				(175)
Foreign currency translation adjustments, net of taxes	3,844				3,844
Net income attributable to noncontrolling interests	4,376						4,376
Distributions to noncontrolling interests	(3,615)						(3,615)
Balances at end of period at Sep. 30, 2020	950,869	27,072	273,576	637,223	8,676	(2,666)	6,988
Balances at beginning of period at Dec. 31, 2020	1,012,406	27,080	274,857	688,819	17,022	(2,666)	7,294
Increase (Decrease) in Stockholders' Equity
Net income attributable to Stewart	237,718			237,718
Dividends on Common Stock	(27,009)			(27,009)
Stock-based compensation	8,494	139	8,355
Stock repurchases	(2,145)	(41)	(2,104)
Stock option and employee stock purchase plan exercises	2,715	64	2,651
Purchase of remaining interest in consolidated subsidiaries	(5,616)		(4,744)				(872)
Change in net unrealized gains and losses on investments, net of taxes	(10,330)				(10,330)
Reclassification adjustment for realized gains and losses on investments, net of taxes	(918)				(918)
Foreign currency translation adjustments, net of taxes	(997)				(997)
Net income attributable to noncontrolling interests	11,639						11,639
Distributions to noncontrolling interests	(11,683)						(11,683)
Net effect of other changes in ownership	2,426						2,426
Balances at end of period at Sep. 30, 2021	1,216,700	27,242	279,015	899,528	4,777	(2,666)	8,804
Balances at beginning of period at Jun. 30, 2021	1,136,073	27,177	274,074	819,834	11,558	(2,666)	6,096
Increase (Decrease) in Stockholders' Equity
Net income attributable to Stewart	88,663			88,663
Dividends on Common Stock	(8,969)			(8,969)
Stock-based compensation	2,615	8	2,607
Stock repurchases	(143)	(2)	(141)
Stock option and employee stock purchase plan exercises	2,534	59	2,475
Change in net unrealized gains and losses on investments, net of taxes	(2,183)				(2,183)
Reclassification adjustment for realized gains and losses on investments, net of taxes	(355)				(355)
Foreign currency translation adjustments, net of taxes	(4,243)				(4,243)
Net income attributable to noncontrolling interests	4,732						4,732
Distributions to noncontrolling interests	(4,430)						(4,430)
Net effect of other changes in ownership	2,406						2,406
Balances at end of period at Sep. 30, 2021	$ 1,216,700	$ 27,242	$ 279,015	$ 899,528	$ 4,777	$ (2,666)	$ 8,804