Debt securities purchased with the intent and ability to hold to their maturity are classified as held-to-maturity securities. All other investment securities are classified as available-for-sale securities.

Information related to the amortized cost, fair value and allowance for credit losses of securities available-for-sale and the related gross unrealized gains and losses recognized in accumulated other comprehensive income (loss) is provided in the table below.


(dollars in thousands)	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Losses		Allowance for Credit Losses		Fair Value
March 31, 2024

U.S. government sponsored agencies	$	144,693	$	0	$	(28,241)	$	0	$	116,452
Mortgage-backed securities: residential	511,037		86		(79,105)		0		432,018

State and municipal securities	548,685		21		(82,695)		0		466,011
Total	$	1,204,415	$	107	$	(190,041)	$	0	$	1,014,481

December 31, 2023

U.S. government sponsored agencies	$	146,692	$	0	$	(27,213)	$	0	$	119,479
Mortgage-backed securities: residential	522,275		118		(74,551)		0		447,842

State and municipal securities	557,352		65		(73,010)		0		484,407
Total	$	1,226,319	$	183	$	(174,774)	$	0	$	1,051,728

Information related to the amortized cost, fair value and allowance for credit losses of securities held-to-maturity and the related gross unrealized gains and losses is presented in the table below.


(dollars in thousands)	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Losses		Allowance for Credit Losses		Fair Value
March 31, 2024
State and municipal securities	$	130,335	$	0	$	(14,868)	$	0	$	115,467

December 31, 2023
State and municipal securities	$	129,918	$	0	$	(10,703)	$	0	$	119,215

The Company has the current intent and ability to hold held-to-maturity securities until maturity. All of the Company's securities designated as held-to-maturity were transferred from the available-for-sale classification. The net unrealized gain or loss on the transferred securities was recorded as a component of accumulated other comprehensive income (loss) at the time of the transfer and is amortized over the remaining life of the underlying securities as an adjustment to the yield on those securities. The net amount of the unamortized unrealized loss on the transferred securities included in accumulated other comprehensive income (loss) was $20.4 million ($16.1 million, net of tax) at March 31, 2024.

Information regarding the amortized cost and fair value of available-for-sale and held-to-maturity debt securities by maturity as of March 31, 2024 is presented below. Maturity information is based on contractual maturity for all securities other than mortgage-backed securities. Actual maturities of securities may differ from contractual maturities because borrowers may have the right to prepay the obligation without a prepayment penalty.


	Available-for-Sale				Held-to-Maturity
(dollars in thousands)	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in one year or less	$	695	$	695	$	0	$	0
Due after one year through five years	7,805		7,149		0		0
Due after five years through ten years	46,433		43,245		0		0
Due after ten years	638,445		531,374		130,335		115,467
	693,378		582,463		130,335		115,467
Mortgage-backed securities	511,037		432,018		0		0
Total debt securities	$	1,204,415	$	1,014,481	$	130,335	$	115,467


	Three Months Ended March 31,
(dollars in thousands)		2024		2023
Sales of securities available-for-sale
Proceeds		$	7,136	$	87,471
Gross gains		0		411
Gross losses		(46)		(395)
Number of securities		15		81

In accordance with ASU No. 2017-8, purchase premiums for callable securities are amortized to the earliest call date and premiums on non-callable securities as well as discounts are recognized in interest income using the interest method over the terms of the securities or over the estimated lives of mortgage-backed securities. Gains and losses on sales are based on the amortized cost of the security sold and recorded on the trade date.

Securities with fair values of $642.0 million and $792.0 million were pledged as of March 31, 2024 and December 31, 2023, respectively, as collateral for borrowings from the Federal Home Loan Bank ("FHLB") and Federal Reserve Bank and for other purposes as permitted or required by law.

Information regarding available-for-sale securities with unrealized losses as of March 31, 2024 and December 31, 2023 is presented on the following page. The tables divide the securities between those with unrealized losses for less than twelve months and those with unrealized losses for twelve months or more.


	Less than 12 months				12 months or more				Total
(dollars in thousands)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
March 31, 2024

U.S. government sponsored agencies	$	0	$	0	$	116,452	$	28,241	$	116,452	$	28,241
Mortgage-backed securities: residential	1,325		11		427,086		79,094		428,411		79,105

State and municipal securities	18,355		430		440,893		82,265		459,248		82,695
Total available-for-sale	$	19,680	$	441	$	984,431	$	189,600	$	1,004,111	$	190,041

December 31, 2023

U.S. government sponsored agencies	$	0	$	0	$	119,479	$	27,213	$	119,479	$	27,213
Mortgage-backed securities: residential	52		0		442,765		74,551		442,817		74,551

State and municipal securities	31,345		440		440,446		72,570		471,791		73,010
Total available-for-sale	$	31,397	$	440	$	1,002,690	$	174,334	$	1,034,087	$	174,774

Information regarding held-to-maturity securities with unrealized losses as of March 31, 2024 and December 31, 2023 is presented below. The table divides the securities between those with unrealized losses for less than twelve months and those with unrealized losses for twelve months or more.


	Less than 12 months				12 months or more				Total
(dollars in thousands)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
March 31, 2024
State and municipal securities	$	0	$	0	$	115,467	$	14,868	$	115,467	$	14,868

December 31, 2023
State and municipal securities	$	0	$	0	$	119,215	$	10,703	$	119,215	$	10,703


	Available-for-Sale			Held-to-Maturity
	Less than 12 months	12 months or more	Total	Less than 12 months	12 months or more	Total
March 31, 2024

U.S. government sponsored agencies	0	17	17	0	0	0
Mortgage-backed securities: residential	4	126	130	0	0	0

State and municipal securities	24	384	408	0	41	41
Total temporarily impaired	28	527	555	0	41	41

December 31, 2023

U.S. government sponsored agencies	0	17	17	0	0	0
Mortgage-backed securities: residential	1	126	127	0	0	0

State and municipal securities	40	370	410	0	41	41
Total temporarily impaired	41	513	554	0	41	41

Available-for-sale debt securities in unrealized loss positions are evaluated for impairment related to credit losses at least quarterly. For available-for-sale debt securities in an unrealized loss position, management first assesses whether it intends to sell, or it is more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through the consolidated income statement. For available-for-sale debt securities that do not meet the above criteria and for held-to-maturity securities, management evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is

less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security and the issuer, among other factors. If this assessment indicates that a credit loss exists, management compares the present value of cash flows expected to be collected from the security with the amortized cost basis of the security. If the present value of cash flows expected to be collected is less than the amortized cost basis for the security, a credit loss exists and an allowance for credit losses is recorded, limited to the amount that the fair value of the security is less than its amortized cost basis. For available-for-sale debt securities, any impairment that has not been recorded through an allowance for credit losses is recognized in other comprehensive income (loss), net of applicable taxes.

No allowance for credit losses for available-for-sale or held-to-maturity debt securities was recorded at March 31, 2024 or December 31, 2023. Accrued interest receivable on securities totaled $7.0 million and $7.6 million at March 31, 2024 and December 31, 2023, respectively, and is excluded from the estimate of credit losses.

The U.S. government sponsored agencies and mortgage-backed securities are either explicitly or implicitly guaranteed by the U.S. government, are highly rated by major credit rating agencies, and have a long history of no credit losses. Therefore, for those securities, we do not record expected credit losses. State and municipal securities credit losses are benchmarked against highly rated municipal securities of similar duration, as published by Moody's, resulting in an immaterial allowance for credit losses.