Securities (Tables)

9 Months Ended

Sep. 30, 2025

Investments, Debt and Equity Securities [Abstract]

Amortized cost and estimated fair value of investment and mortgage-backed securities

The amortized cost, gross unrealized gains and losses and estimated fair value of investment and mortgage-backed AFS and HTM securities, net of allowance for credit losses, as of September 30, 2025 and December 31, 2024 are reflected in the tables below (in thousands):


	September 30, 2025
	Amortized		Gross Unrealized		Gross Unrealized		Less: Allowance for		Estimated
AVAILABLE FOR SALE	Cost		Gains		Losses		Credit Losses		Fair Value
Investment securities:
U.S. Treasury	$	49,650	$	12	$	—	$	—	$	49,662

State and political subdivisions	274,142		1,195		27,246		—		248,091
Corporate bonds and other	16,717		460		234		—		16,943

MBS: (1)
Residential	965,126		11,311		998		—		975,439
Commercial	2,229		67		—		—		2,296
Total	$	1,307,864	$	13,045	$	28,478	$	—	$	1,292,431



	Amortized		Gross Unrealized		Gross Unrealized		Estimated		Less: Allowance for		Net Carrying
HELD TO MATURITY	Cost		Gains		Losses		Fair Value		Credit Losses		Amount
Investment securities:














State and political subdivisions	$	1,042,425	$	776	$	149,376	$	893,825	$	26	$	1,042,399
Corporate bonds and other	112,668		665		2,716		110,617		29		112,639
MBS: (1)
Residential	79,349		12		5,416		73,945		—		79,349
Commercial	29,014		—		1,215		27,799		—		29,014
Total	$	1,263,456	$	1,453	$	158,723	$	1,106,186	$	55	$	1,263,401


	December 31, 2024
	Amortized		Gross Unrealized		Gross Unrealized		Less: Allowance for		Estimated
AVAILABLE FOR SALE	Cost		Gains		Losses		Credit Losses		Fair Value
Investment securities:
U.S. Treasury	$	173,880	$	76	$	—	$	—	$	173,956

State and political subdivisions	458,013		36		43,717		—		414,332
Corporate bonds and other	14,646		263		401		—		14,508

MBS: (1)
Residential	935,639		835		10,088		—		926,386
Commercial	5,238		—		526		—		4,712
Total	$	1,587,416	$	1,210	$	54,732	$	—	$	1,533,894




















	Amortized		Gross Unrealized		Gross Unrealized		Estimated		Less: Allowance for		Net Carrying
HELD TO MATURITY	Cost		Gains		Losses		Fair Value		Credit Losses		Amount
Investment securities:
State and political subdivisions	$	1,040,912	$	4,004	$	152,697	$	892,219	$	—	$	1,040,912
Corporate bonds and other	124,095		17		6,553		117,559		—		124,095
MBS: (1)
Residential	84,660		8		8,549		76,119		—		84,660
Commercial	29,567		—		1,982		27,585		—		29,567
Total	$	1,279,234	$	4,029	$	169,781	$	1,113,482	$	—	$	1,279,234

(1) All MBS are issued and/or guaranteed by U.S. government agencies or U.S. GSEs.

Investment

The following tables present the fair value and unrealized losses on AFS, if applicable, for which an allowance for credit losses has not been recorded, as well as HTM investment securities and MBS, if applicable, as of September 30, 2025 and December 31, 2024, segregated by major security type and length of time in a continuous loss position (in thousands):


	September 30, 2025
	Less Than 12 Months				More Than 12 Months				Total
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
AVAILABLE FOR SALE
Investment securities:


State and political subdivisions	$	—	$	—	$	200,368	$	27,246	$	200,368	$	27,246
Corporate bonds and other	—		—		5,748		234		5,748		234

MBS:
Residential	64,783		260		10,828		738		75,611		998

Total	$	64,783	$	260	$	216,944	$	28,218	$	281,727	$	28,478

HELD TO MATURITY
Investment securities:
State and political subdivisions	$	127,853	$	5,503	$	716,470	$	143,873	$	844,323	$	149,376
Corporate bonds and other	—		—		84,432		2,716		84,432		2,716
MBS:
Residential	2,460		197		71,055		5,219		73,515		5,416
Commercial	—		—		27,799		1,215		27,799		1,215
Total	$	130,313	$	5,700	$	899,756	$	153,023	$	1,030,069	$	158,723

	December 31, 2024
	Less Than 12 Months				More Than 12 Months				Total
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
AVAILABLE FOR SALE
Investment securities:


State and political subdivisions	$	12,089	$	64	$	398,304	$	43,653	$	410,393	$	43,717
Corporate bonds and other	2,967		33		5,612		368		8,579		401

MBS:
Residential	723,855		6,517		31,527		3,571		755,382		10,088
Commercial	2,223		12		2,489		514		4,712		526
Total	$	741,134	$	6,626	$	437,932	$	48,106	$	1,179,066	$	54,732

HELD TO MATURITY
Investment securities:
State and political subdivisions	$	73,272	$	1,779	$	704,563	$	150,918	$	777,835	$	152,697
Corporate bonds and other	2,212		149		111,392		6,404		113,604		6,553
MBS:
Residential	2,548		292		73,064		8,257		75,612		8,549
Commercial	—		—		27,585		1,982		27,585		1,982
Total	$	78,032	$	2,220	$	916,604	$	167,561	$	994,636	$	169,781

Interest income recognized on securities

The following table reflects interest income recognized on securities for the periods presented (in thousands):



	Three Months Ended September 30,
	2025		2024
U.S. Treasury	$	734	$	2,315

State and political subdivisions	11,424		12,994

Corporate bonds and other	1,665		1,654
MBS	14,174		11,976
Total interest income on securities	$	27,997	$	28,939



	Nine Months Ended September 30,
	2025		2024
U.S. Treasury	$	3,737	$	6,404

State and political subdivisions	34,743		41,151
Corporate bonds and other	4,875		5,182
MBS	40,737		33,179
Total interest income on securities	$	84,092	$	85,916

Amortized cost, carrying value and fair value of securities presented by contractual maturity

The amortized cost and estimated fair value of AFS and HTM securities at September 30, 2025, are presented below by contractual maturity (in thousands):


	September 30, 2025
	Amortized Cost		Fair Value
AVAILABLE FOR SALE
Investment securities:
Due in one year or less	$	50,084	$	50,098
Due after one year through five years	4,991		5,081
Due after five years through ten years	16,007		16,195
Due after ten years	269,427		243,322
	340,509		314,696
MBS:	967,355		977,735
Total	$	1,307,864	$	1,292,431


	September 30, 2025
	Amortized Cost		Fair Value
HELD TO MATURITY
Investment securities:
Due in one year or less	$	140	$	139
Due after one year through five years	25,238		25,351
Due after five years through ten years	125,603		123,125
Due after ten years	1,004,112		855,827
	1,155,093		1,004,442
MBS:	108,363		101,744
Total	$	1,263,456	$	1,106,186

Unrealized and realized gains (losses) recognized in net income on equity investments

The following is a summary of unrealized and realized gains and losses on equity investments recognized in other noninterest income in the consolidated statements of income during the periods presented (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Net gains (losses) recognized during the period on equity investments	$	51	$	191	$	146	$	112
Less: Net gains recognized during the period on equity investments sold during the period	—		—		—		—
Unrealized gains (losses) recognized during the reporting period on equity investments held at the reporting date	$	51	$	191	$	146	$	112

SOUTHSIDE BANCSHARES INC 10-Q