INVESTMENTS (Tables)

9 Months Ended

Sep. 30, 2025

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, 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	$	(5)	$	94
Securities of U.S. government agencies and corporations	0		0		0		0		73,204		0		(6,771)		66,433
Mortgage-backed securities - residential	0		0		0		0		1,358,833		8,152		(74,625)		1,292,360
Mortgage-backed securities - commercial	28,176		0		(3,669)		24,507		311,509		957		(19,457)		293,009
Collateralized mortgage obligations	6,349		0		(530)		5,819		605,089		3,917		(38,729)		570,277
Obligations of state and other political subdivisions	8,320		80		(188)		8,212		621,066		634		(102,632)		519,068
Asset-backed securities	0		0		0		0		563,927		1,959		(14,082)		551,804
Other securities	28,750		0		(1,377)		27,373		136,269		522		(7,241)		129,550
Total	$	71,595	$	80	$	(5,764)	$	65,911	$	3,669,996	$	16,141	$	(263,542)	$	3,422,595

The following is a summary of HTM and AFS investment securities as of December 31, 2024:


	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	$	(9)	$	90
Securities of U.S. government agencies and corporations	0		0		0		0		83,224		0		(11,546)		71,678
Mortgage-backed securities - residential	0		0		0		0		1,102,242		508		(104,208)		998,542
Mortgage-backed securities - commercial	30,444		0		(4,454)		25,990		382,727		26		(25,381)		357,372
Collateralized mortgage obligations	7,007		0		(788)		6,219		620,315		1,449		(52,599)		569,165
Obligations of state and other political subdivisions	8,259		42		(339)		7,962		630,813		357		(109,904)		521,266
Asset-backed securities	0		0		0		0		555,484		998		(22,379)		534,103
Other securities	31,250		0		(2,432)		28,818		137,748		120		(6,308)		131,560
Total	$	76,960	$	42	$	(8,013)	$	68,989	$	3,512,652	$	3,458	$	(332,334)	$	3,183,776

Summary of Investment Securities by Estimated Maturity

The following table provides a summary of investment securities by contractual maturity as of September 30, 2025, 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	$	715	$	715	$	14,381	$	13,280
Due after one year through five years	6,167		6,247		187,361		168,726
Due after five years through ten years	28,750		27,373		158,546		135,062
Due after ten years	1,438		1,250		470,350		398,077
Mortgage-backed securities - residential	0		0		1,358,833		1,292,360
Mortgage-backed securities - commercial	28,176		24,507		311,509		293,009
Collateralized mortgage obligations	6,349		5,819		605,089		570,277
Asset-backed securities	0		0		563,927		551,804
Total	$	71,595	$	65,911	$	3,669,996	$	3,422,595

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, 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	$	94	$	(5)	$	94	$	(5)
Securities of U.S. Government agencies and corporations	0		0		66,433		(6,771)		66,433		(6,771)
Mortgage-backed securities - residential	91,271		(532)		586,441		(74,093)		677,712		(74,625)
Mortgage-backed securities - commercial	26,320		(92)		185,677		(19,365)		211,997		(19,457)
Collateralized mortgage obligations	7,218		(15)		292,317		(38,714)		299,535		(38,729)
Obligations of state and other political subdivisions	11,297		(19)		459,190		(102,613)		470,487		(102,632)
Asset-backed securities	26,305		(23)		66,899		(14,059)		93,204		(14,082)
Other securities	3,499		(1)		101,030		(7,240)		104,529		(7,241)
Total	$	165,910	$	(682)	$	1,758,081	$	(262,860)	$	1,923,991	$	(263,542)


	December 31, 2024
	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	$	90	$	(9)	$	90	$	(9)
Securities of U.S. Government agencies and corporations	0		0		71,678		(11,546)		71,678		(11,546)
Mortgage-backed securities - residential	417,516		(9,130)		503,321		(95,078)		920,837		(104,208)
Mortgage-backed securities - commercial	26,516		(67)		286,589		(25,314)		313,105		(25,381)
Collateralized mortgage obligations	120,670		(1,776)		296,813		(50,823)		417,483		(52,599)
Obligations of state and other political subdivisions	19,636		(351)		478,083		(109,553)		497,719		(109,904)
Asset-backed securities	26,389		(189)		159,135		(22,190)		185,524		(22,379)
Other securities	9,988		(12)		115,452		(6,296)		125,440		(6,308)
Total	$	620,715	$	(11,525)	$	1,911,161	$	(320,809)	$	2,531,876	$	(332,334)

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, 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		24,507		(3,669)		24,507		(3,669)
Collateralized mortgage obligations	0		0		5,819		(530)		5,819		(530)
Obligations of state and other political subdivisions	478		(1)		1,250		(187)		1,728		(188)
Asset-backed securities	0		0		0		0		0		0
Other securities	0		0		27,373		(1,377)		27,373		(1,377)
Total	$	478	$	(1)	$	58,949	$	(5,763)	$	59,427	$	(5,764)


	December 31, 2024
	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		25,990		(4,454)		25,990		(4,454)
Collateralized mortgage obligations	0		0		6,219		(788)		6,219		(788)
Obligations of state and other political subdivisions	3,111		(33)		2,288		(306)		5,399		(339)
Asset-backed securities	0		0		0		0		0		0
Other securities	0		0		28,818		(2,432)		28,818		(2,432)
Total	$	3,111	$	(33)	$	63,315	$	(7,980)	$	66,426	$	(8,013)