INVESTMENTS (Tables)

9 Months Ended

Sep. 30, 2026

Investments, Debt and Equity Securities [Abstract]

Summary of Held-To-Maturity and Available-For-Sale Investment Securities

The following is a summary of HTM and AFS investment securities as of September 30, 2026:


	Held-to-maturity								Available-for-sale
(Dollars in thousands)	Amortized cost		Unrecognized gain		Unrecognized loss		Fair value		Amortized cost		Unrealized gain		Unrealized loss		Fair value
U.S. Treasuries	$	0	$	0	$	0	$	0	$	100	$	0	$	(5)	$	95
Securities of U.S. government agencies and corporations	0		0		0		0		104,978		135		(5,231)		99,882
Mortgage-backed securities - residential	0		0		0		0		2,002,626		31		(199,374)		1,803,283
Mortgage-backed securities - commercial	25,732		0		(4,396)		21,336		425,734		136		(30,792)		395,078
Collateralized mortgage obligations	5,402		0		(710)		4,692		1,084,939		10		(78,811)		1,006,138
Obligations of state and other political subdivisions	7,187		0		(315)		6,872		771,939		306		(133,628)		638,617
Asset-backed securities	0		0		0		0		523,108		116		(12,294)		510,930
Other securities	0		0		0		0		184,972		17		(3,708)		181,281
Total	$	38,321	$	0	$	(5,421)	$	32,900	$	5,098,396	$	751	$	(463,843)	$	4,635,304

The following is a summary of HTM and AFS investment securities as of December 31, 2025:


	Held-to-maturity								Available-for-sale
(Dollars in thousands)	Amortized cost		Unrecognized gain		Unrecognized loss		Fair value		Amortized cost		Unrealized gain		Unrealized loss		Fair value
U.S. Treasuries	$	0	$	0	$	0	$	0	$	99	$	0	$	(4)	$	95
Securities of U.S. government agencies and corporations	0		0		0		0		0		0		0		0
Mortgage-backed securities - residential	0		0		0		0		1,607,916		11,265		(69,767)		1,549,414
Mortgage-backed securities - commercial	27,373		0		(3,392)		23,981		394,129		1,212		(13,741)		381,600
Collateralized mortgage obligations	6,088		0		(499)		5,589		741,819		3,765		(36,347)		709,237
Obligations of state and other political subdivisions	8,334		60		(179)		8,215		706,668		931		(89,509)		618,090
Asset-backed securities	0		0		0		0		568,366		1,817		(13,639)		556,544
Other securities	16,750		0		(201)		16,549		163,078		1,063		(7,189)		156,952
Total	$	58,545	$	60	$	(4,271)	$	54,334	$	4,182,075	$	20,053	$	(230,196)	$	3,971,932

Summary of Investment Securities by Estimated Maturity

The following table provides a summary of investment securities by contractual maturity as of September 30, 2026, except for residential and commercial mortgage-backed securities, collateralized mortgage obligations and asset-backed securities, which are shown as single totals due to the unpredictability of the timing in principal repayments.


	Held-to-maturity				Available-for-sale
(Dollars in thousands)	Amortized cost		Fair value		Amortized cost		Fair value
By Contractual Maturity:
Due in one year or less	$	495	$	493	$	37,621	$	37,493
Due after one year through five years	5,438		5,348		81,754		72,700
Due after five years through ten years	0		0		263,969		229,926
Due after ten years	1,254		1,031		678,645		579,756
Mortgage-backed securities - residential	0		0		2,002,626		1,803,283
Mortgage-backed securities - commercial	25,732		21,336		425,734		395,078
Collateralized mortgage obligations	5,402		4,692		1,084,939		1,006,138
Asset-backed securities	0		0		523,108		510,930
Total	$	38,321	$	32,900	$	5,098,396	$	4,635,304

Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value

The following tables provide the fair value and gross unrealized losses of AFS investment securities in an unrealized loss position for which an ACL has not been recorded, aggregated by investment category and the length of time the individual securities have been in a continuous loss position:


	September 30, 2026
	Less than 12 months				12 months or more				Total
(Dollars in thousands)	Fair value		Unrealized loss		Fair value		Unrealized loss		Fair value		Unrealized loss
U.S. Treasuries	$	0	$	0	$	95	$	(5)	$	95	$	(5)
Securities of U.S. Government agencies and corporations	80,609		(5,231)		0		0		80,609		(5,231)
Mortgage-backed securities - residential	1,408,559		(112,009)		377,631		(87,365)		1,786,190		(199,374)
Mortgage-backed securities - commercial	234,818		(14,799)		129,252		(15,993)		364,070		(30,792)
Collateralized mortgage obligations	748,886		(32,854)		240,608		(45,957)		989,494		(78,811)
Obligations of state and other political subdivisions	208,210		(16,964)		413,019		(116,664)		621,229		(133,628)
Asset-backed securities	320,447		(2,331)		41,773		(9,963)		362,220		(12,294)
Other securities	103,729		(1,721)		54,035		(1,987)		157,764		(3,708)
Total	$	3,105,258	$	(185,909)	$	1,256,413	$	(277,934)	$	4,361,671	$	(463,843)


	December 31, 2025
	Less than 12 months				12 months or more				Total
(Dollars in thousands)	Fair value		Unrealized loss		Fair value		Unrealized loss		Fair value		Unrealized loss
U.S. Treasuries	$	0	$	0	$	95	$	(4)	$	95	$	(4)
Securities of U.S. Government agencies and corporations	0		0		0		0		0		0
Mortgage-backed securities - residential	277,394		(1,349)		536,694		(68,418)		814,088		(69,767)
Mortgage-backed securities - commercial	39,084		(108)		166,649		(13,633)		205,733		(13,741)
Collateralized mortgage obligations	56,942		(130)		286,606		(36,217)		343,548		(36,347)
Obligations of state and other political subdivisions	71,825		(511)		466,766		(88,998)		538,591		(89,509)
Asset-backed securities	70,967		(48)		54,351		(13,591)		125,318		(13,639)
Other securities	7,321		(54)		76,141		(7,135)		83,462		(7,189)
Total	$	523,533	$	(2,200)	$	1,587,302	$	(227,996)	$	2,110,835	$	(230,196)

The following tables provide the fair value and gross unrecognized losses of HTM investment securities in an unrecognized loss position for which an ACL has not been recorded, aggregated by investment category and the length of time the individual securities have been in a continuous loss position:


	September 30, 2026
	Less than 12 months				12 months or more				Total
(Dollars in thousands)	Fair value		Unrecognized loss		Fair value		Unrecognized loss		Fair value		Unrecognized loss
U.S. Treasuries	$	0	$	0	$	0	$	0	$	0	$	0
Securities of U.S. Government agencies and corporations	0		0		0		0		0		0
Mortgage-backed securities - residential	0		0		0		0		0		0
Mortgage-backed securities - commercial	0		0		21,336		(4,396)		21,336		(4,396)
Collateralized mortgage obligations	0		0		4,692		(710)		4,692		(710)
Obligations of state and other political subdivisions	4,113		(92)		1,031		(223)		5,144		(315)
Asset-backed securities	0		0		0		0		0		0
Other securities	0		0		0		0		0		0
Total	$	4,113	$	(92)	$	27,059	$	(5,329)	$	31,172	$	(5,421)


	December 31, 2025
	Less than 12 months				12 months or more				Total
(Dollars in thousands)	Fair value		Unrecognized loss		Fair value		Unrecognized loss		Fair value		Unrecognized loss
U.S. Treasuries	$	0	$	0	$	0	$	0	$	0	$	0
Securities of U.S. Government agencies and corporations	0		0		0		0		0		0
Mortgage-backed securities - residential	0		0		0		0		0		0
Mortgage-backed securities - commercial	0		0		23,981		(3,392)		23,981		(3,392)
Collateralized mortgage obligations	0		0		5,589		(499)		5,589		(499)
Obligations of state and other political subdivisions	2,273		(4)		1,217		(175)		3,490		(179)
Asset-backed securities	0		0		0		0		0		0
Other securities	0		0		16,549		(201)		16,549		(201)
Total	$	2,273	$	(4)	$	47,336	$	(4,267)	$	49,609	$	(4,271)