
(dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Allowance for Credit Losses		Estimated Fair Value
September 30, 2024
Investment securities available-for-sale:
U.S. treasury bonds	$	49,970	$	—	$	(567)	$	—	$	49,403
U.S. agency securities	690,699		—		(37,422)		—		653,277
Residential mortgage-backed securities	745,006		125		(75,086)		—		670,045
Commercial mortgage-backed securities	53,711		—		(3,495)		—		50,216
Municipal bonds	8,652		—		(385)		—		8,267
Corporate bonds	2,000		—		(185)		(17)		1,798

Total available-for-sale securities	$	1,550,038	$	125	$	(117,140)	$	(17)	$	1,433,006


(dollars in thousands)	Amortized Cost		Gross Unrecognized Gains		Gross Unrecognized Losses		Estimated Fair Value
September 30, 2024
Investment securities held-to-maturity:


Residential mortgage-backed securities	$	621,203	$	—	$	(66,264)	$	554,939
Commercial mortgage-backed securities	89,269		—		(10,008)		79,261
Municipal bonds	120,307		—		(8,024)		112,283
Corporate bonds	132,383		—		(10,441)		121,942

Total	$	963,162	$	—	$	(94,737)	$	868,425
Allowance for credit losses	(1,237)
Total held-to-maturity securities, net of ACL	$	961,925


(dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Allowance for Credit Losses		Estimated Fair Value
December 31, 2023
Investment securities available-for-sale:
U.S. treasury bonds	$	49,894	$	—	$	(1,993)	$	—	$	47,901
U.S. agency securities	729,090		—		(57,693)		—		671,397
Residential mortgage-backed securities	823,992		45		(96,684)		—		727,353
Commercial mortgage-backed securities	54,557		—		(4,993)		—		49,564
Municipal bonds	8,783		—		(293)		—		8,490
Corporate bonds	2,000		—		(300)		(17)		1,683
Total available-for-sale securities	$	1,668,316	$	45	$	(161,956)	$	(17)	$	1,506,388


(dollars in thousands)	Amortized Cost		Gross Unrecognized Gains		Gross Unrecognized Losses		Estimated Fair Value
December 31, 2023
Investment securities held-to-maturity:


Residential mortgage-backed securities	$	670,043	$	—	$	(79,980)	$	590,063
Commercial mortgage-backed securities	90,227		—		(12,867)		77,360
Municipal bonds	125,114		5		(8,540)		116,579
Corporate bonds	132,309		—		(14,729)		117,580

Total	$	1,017,693	$	5	$	(116,116)	$	901,582
Allowance for credit losses	(1,956)
Total held-to-maturity securities, net of ACL	$	1,015,737

At September 30, 2024 and December 31, 2023, the Company held $37.7 million and $25.7 million, respectively, of equity securities in a combination of Federal Reserve System ("Federal Reserve Board," "Federal Reserve" or "FRB") and FHLB stocks, which are required to be held for regulatory purposes. These securities cannot be disposed of other than through redemption by the issuer and, if redeemed, would be redeemed at the original cost.

At September 30, 2024 and December 31, 2023, the Company had $46.5 million and $51.7 million, respectively, of unamortized unrealized losses outstanding following the transfer of investment securities from AFS to HTM in 2022. These unrealized losses are included in accumulated other comprehensive loss and are amortized through interest income as a yield adjustment over the remaining term of the securities.

Accrued interest receivable on investment securities totaled $7.4 million and $7.6 million at September 30, 2024 and December 31, 2023, respectively. The accrued interest receivable is excluded from the amortized cost of the securities and is reported in other assets in the Consolidated Balance Sheets.


		Less Than 12 Months				12 Months or Greater				Total
(dollars in thousands)	Number of Securities	Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses
September 30, 2024
Investment securities available-for-sale:
U.S. treasury bonds	2	$	—	$	—	$	49,403	$	(567)	$	49,403	$	(567)
U. S. agency securities	76	2,498		(3)		650,779		(37,419)		653,277		(37,422)
Residential mortgage-backed securities	146	—		—		660,627		(75,086)		660,627		(75,086)
Commercial mortgage-backed securities	13	—		—		50,216		(3,495)		50,216		(3,495)
Municipal bonds	1	—		—		8,267		(385)		8,267		(385)
Corporate bonds	1	—		—		1,797		(185)		1,797		(185)
Total	239	$	2,498	$	(3)	$	1,421,089	$	(117,137)	$	1,423,587	$	(117,140)


		Less Than 12 Months				12 Months or Greater				Total
(dollars in thousands)	Number of Securities	Estimated Fair Value		Unrecognized Losses		Estimated Fair Value		Unrecognized Losses		Estimated Fair Value		Unrecognized Losses
September 30, 2024
Investment securities held-to-maturity:
Residential mortgage-backed securities	141	$	—	$	—	$	554,939	$	(66,264)	$	554,939	$	(66,264)
Commercial mortgage-backed securities	16	—		—		79,261		(10,008)		79,261		(10,008)
Municipal bonds	38	3,503		(23)		107,779		(8,001)		111,282		(8,024)
Corporate bonds	30	—		—		109,899		(10,441)		109,899		(10,441)
Total	225	$	3,503	$	(23)	$	851,878	$	(94,714)	$	855,381	$	(94,737)


		Less Than 12 Months				12 Months or Greater				Total
(dollars in thousands)	Number of Securities	Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses
December 31, 2023
Investment securities available-for-sale:
U.S. treasury bonds	2	$	—	$	—	$	47,901	$	(1,993)	$	47,901	$	(1,993)
U. S. agency securities	78	3,084		(4)		668,313		(57,689)		671,397		(57,693)
Residential mortgage-backed securities	149	—		—		718,042		(96,684)		718,042		(96,684)
Commercial mortgage-backed securities	13	—		—		49,564		(4,993)		49,564		(4,993)
Municipal bonds	1	—		—		8,490		(293)		8,490		(293)
Corporate bonds	1	—		—		1,683		(300)		1,683		(300)
Total	244	$	3,084	$	(4)	$	1,493,993	$	(161,952)	$	1,497,077	$	(161,956)


		Less Than 12 Months				12 Months or Greater				Total
(dollars in thousands)	Number of Securities	Estimated Fair Value		Unrecognized Losses		Estimated Fair Value		Unrecognized Losses		Estimated Fair Value		Unrecognized Losses
December 31, 2023
Investment securities held-to-maturity:
Residential mortgage-backed securities	142	$	—	$	—	$	590,063	$	(79,980)	$	590,063	$	(79,980)
Commercial mortgage-backed securities	16	—		—		77,360		(12,867)		77,360		(12,867)
Municipal bonds	40	—		—		113,031		(8,540)		113,031		(8,540)
Corporate bonds	30	—		—		105,523		(14,729)		105,523		(14,729)
Total	228	$	—	$	—	$	885,977	$	(116,116)	$	885,977	$	(116,116)

Unrealized losses at September 30, 2024 were generally attributable to changes in market interest rates and interest spread relationships subsequent to the dates the securities were originally purchased and were considered to be temporary, and not due to credit quality concerns on the investment securities. The fair values of these securities are expected to recover as the securities approach their respective maturity dates. The Company does not intend to sell and it is likely that it will not be required to sell the securities prior to their anticipated recovery.

The Company measures its AFS and HTM security portfolios for current expected credit losses as part of its ACL analysis. For further information on provision for credit losses on AFS and HTM securities, including balances for the three and nine months ended September 30, 2024 and 2023, see Allowance for Credit Losses discussion in "Note 1. Summary of Significant Accounting Policies". At September 30, 2024, the Company had a total allowance of $17 thousand on its AFS securities and $1.2 million on its HTM securities, each of which primarily comprise allowances for corporate bonds.

The following table summarizes the Company's investment in AFS securities and HTM securities by contractual maturity. Expected maturities for mortgage-backed securities ("MBS") will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.


	September 30, 2024
(dollars in thousands)	Amortized Cost		Estimated Fair Value
Investment securities available-for-sale:
Within one year	$	226,404	$	223,552
One to five years	419,569		394,901
Five to ten years	85,553		76,816
Beyond ten years	19,795		17,493
Residential mortgage-backed securities	745,006		670,045
Commercial mortgage-backed securities	53,711		50,216

Less: allowance for credit losses	—		(17)
Total investment securities available-for-sale	1,550,038		1,433,006

Investment securities held-to-maturity:
Within one year	7,699		7,636
One to five years	57,804		56,704
Five to ten years	118,626		107,212
Beyond ten years	68,561		62,673
Residential mortgage-backed securities:	621,203		554,939
Commercial mortgage-backed securities	89,269		79,261

Less: allowance for credit losses	(1,237)		—
Total investment securities held-to-maturity	961,925		868,425
Total	$	2,511,963	$	2,301,431

For the three and nine months ended September 30, 2024, gross realized gains on calls of investment securities were $3 thousand and $10 thousand, respectively, as compared to $5 thousand and $126 thousand for the three and nine months ended September 30, 2023.

There were no gross realized losses on sales or calls of investment securities during the three and nine months ended September 30, 2024, nor during the three months ended September 30, 2023. During the nine months ended September 30, 2023, there were $140 thousand of gross realized losses on sales or calls of investment securities.

Gross sales and call proceeds were $4.5 million and $31.6 million for the three and nine months ended September 30, 2024, respectively, and $2.6 million and $11.2 million for the same periods in 2023.

The book value of securities pledged as collateral for certain government deposits, securities sold under agreements to repurchase, and certain lines of credit with correspondent banks at September 30, 2024 and December 31, 2023 was $1.4 billion and $2.1 billion, respectively. These balances were well in excess of required amounts in order to operationally provide significant reserve amounts for new business. As of September 30, 2024 and December 31, 2023, there were no holdings of securities of any one issuer, other than the U.S. Government and U.S. agency securities, that exceeded ten percent of shareholders' equity.