Investment Securities (Tables)

9 Months Ended

Sep. 30, 2025

Investments, Debt and Equity Securities [Abstract]

Schedule of Amortized Cost and Fair Values of Investment Securities

The following table presents the amortized cost and estimated fair values of investment securities:


	September 30, 2025
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available for Sale	(dollars in thousands)


State and municipal securities	$	954,132	$	155	$	(142,551)	$	811,736
Corporate debt securities	261,087		1,125		(7,173)		255,039
Collateralized mortgage obligations	1,129,328		13,744		(7,630)		1,135,442
Residential mortgage-backed securities	877,560		4,923		(23,491)		858,992
Commercial mortgage-backed securities	624,969		7		(92,109)		532,867

Total	$	3,847,076	$	19,954	$	(272,954)	$	3,594,076

Held to Maturity
Residential mortgage-backed securities	$	597,922	$	3,819	$	(45,910)	$	555,831
Commercial mortgage-backed securities	853,272		—		(123,753)		729,519
Total	$	1,451,194	$	3,819	$	(169,663)	$	1,285,350


	December 31, 2024
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available for Sale	(dollars in thousands)


State and municipal securities	$	960,227	$	106	$	(145,446)	$	814,887
Corporate debt securities	313,681		1,123		(14,434)		300,370
Collateralized mortgage obligations	798,157		4,629		(13,901)		788,885
Residential mortgage-backed securities	1,029,846		30		(40,001)		989,875
Commercial mortgage-backed securities	617,605		—		(100,723)		516,882

Total	$	3,719,516	$	5,888	$	(314,505)	$	3,410,899



Held to Maturity
Residential mortgage-backed securities	$	537,856	$	2	$	(60,162)	$	477,696
Commercial mortgage-backed securities	857,713		—		(151,960)		705,753
Total	$	1,395,569	$	2	$	(212,122)	$	1,183,449

Schedule of Amortized Cost and Fair Values of Debt Securities by Contractual Maturities

The amortized cost and estimated fair values of debt securities as of September 30, 2025, by contractual maturity, are shown in the following table. Actual maturities may differ from contractual maturities because issuers may have the right to call, or borrowers may have the right to prepay, with or without call or prepayment penalties.


		September 30, 2025
		Available for Sale				Held to Maturity
		Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(dollars in thousands)
Due in one year or less		$	14,985	$	14,973	$	—	$	—
Due from one year to five years		134,559		133,654		—		—
Due from five years to ten years		234,449		228,280		—		—
Due after ten years		831,226		689,868		—		—
		1,215,219		1,066,775		—		—
Residential mortgage-backed securities(1)		877,560		858,992		597,922		555,831
Commercial mortgage-backed securities(1)		624,969		532,867		853,272		729,519
Collateralized mortgage obligations(1)		1,129,328		1,135,442		—		—
Total		$	3,847,076	$	3,594,076	$	1,451,194	$	1,285,350

(1) Maturities for mortgage-backed securities and collateralized mortgage obligations are dependent upon the interest rate environment and prepayments on the

underlying loans.

Summary of Gains and Losses from Equity and Debt Securities, and Losses Recognized from Other-than-Temporary Impairment

The following table presents information related to gross realized gains and losses on the sales of securities for the periods presented:


	Gross Realized Gains		Gross Realized Losses		Net Gains (Losses)
Three months ended	(dollars in thousands)
September 30, 2025	$	—	$	—	$	—
September 30, 2024	88		(89)		(1)

Nine months ended
September 30, 2025	$	663	$	(665)	$	(2)
September 30, 2024	179		(20,462)		(20,283)