Investment Securities (Tables)

6 Months Ended

Jun. 30, 2024

Investments, Debt and Equity Securities [Abstract]

Amortized Cost, Estimated Fair Value and Allowance for Credit Losses of HTM Securities and AFS Securities by Contractual Maturities

The following table shows the amortized cost, the estimated fair value and the allowance for credit losses of the held-to-maturity securities and available-for-sale securities at June 30, 2024 and December 31, 2023, by contractual maturity within each type:

	At June 30, 2024
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Allowance for Credit Losses		Fair Value
Securities Held-to-Maturity
Residential mortgage-backed securities:
After 1 year to 5 years	$	1,469	$	—	$	(52)	$	—	$	1,417
After 5 years to 10 years	11,344		—		(598)		—		10,746
Over 10 years	127,299		—		(18,870)		—		108,429
	140,112		—		(19,520)		—		120,592
Total	$	140,112	$	—	$	(19,520)	$	—	$	120,592
Securities Available-for-Sale
State and political subdivisions:
Within 1 year	$	1,299	$	—	$	(23)	$	—	$	1,276
	1,299		—		(23)		—		1,276
Residential mortgage-backed securities:
After 1 year to 5 years	437		—		(15)		—		422
After 5 years to 10 years	12,511		—		(983)		—		11,528
Over 10 years	296,722		128		(38,444)		—		258,406
	309,670		128		(39,442)		—		270,356
Collateralized mortgage obligations:
After 5 years to 10 years	194		—		(9)		—		185
Over 10 years	1,822		—		(177)		—		1,645
	2,016		—		(186)		—		1,830
Corporate bonds:
Within 1 year	3,494		1		(50)		(3)		3,442
After 1 year to 5 years	13,312		9		(594)		(37)		12,690
After 5 years to 10 years	60,000		—		(6,077)		(741)		53,182
	76,806		10		(6,721)		(781)		69,314
Total	$	389,791	$	138	$	(46,372)	$	(781)	$	342,776

	At December 31, 2023
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Allowance for Credit Losses		Fair Value
Securities Held-to-Maturity
Residential mortgage-backed securities:
After 1 year to 5 years	$	1,871	$	—	$	(62)	$	—	$	1,809
After 5 years to 10 years	12,047		—		(462)		—		11,585
Over 10 years	131,859		—		(16,976)		—		114,883
	145,777		—		(17,500)		—		128,277
Total	$	145,777	$	—	$	(17,500)	$	—	$	128,277
Securities Available-for-Sale
State and political subdivisions:
Within 1 year	$	1,030	$	—	$	(1)	$	—	$	1,029
After 1 year to 5 years	1,298		—		(26)		—		1,272
	2,328		—		(27)		—		2,301
Residential mortgage-backed securities:
After 1 year to 5 years	567		—		(20)		—		547
After 5 years to 10 years	13,653		—		(964)		—		12,689
Over 10 years	285,628		131		(34,443)		—		251,316
	299,848		131		(35,427)		—		264,552
Collateralized mortgage obligations:
After 5 years to 10 years	241		—		(11)		—		230
Over 10 years	1,960		—		(189)		—		1,771
	2,201		—		(200)		—		2,001
Corporate bonds:
Within 1 year	18,011		1		(176)		(27)		17,809
After 1 year to 5 years	13,339		23		(671)		(43)		12,648
After 5 years to 10 years	60,000		—		(7,097)		(661)		52,242
	91,350		24		(7,944)		(731)		82,699
Total	$	395,727	$	155	$	(43,598)	$	(731)	$	351,553

Amount of Securities in Unrealized Loss Position With No Allowance For Credit Losses

The following table shows the fair value of securities that were in an unrealized loss position for which an allowance for credit losses has not been recorded at June 30, 2024 and December 31, 2023, by the length of time those securities were in a continuous loss position.

	Less than Twelve Months				Twelve Months or Longer				Total
(Dollars in thousands)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
At June 30, 2024
Securities Held-to-Maturity
Residential mortgage-backed securities	$	1,071	$	(24)	$	119,521	$	(19,496)	$	120,592	$	(19,520)
Total	$	1,071	$	(24)	$	119,521	$	(19,496)	$	120,592	$	(19,520)
Securities Available-for-Sale
Residential mortgage-backed securities	$	18,432	$	(116)	$	237,568	$	(39,326)	$	256,000	$	(39,442)
Collateralized mortgage obligations	—		—		1,830		(186)		1,830		(186)
Corporate bonds	984		(1)		—		—		984		(1)
Total	$	19,416	$	(117)	$	239,398	$	(39,512)	$	258,814	$	(39,629)
At December 31, 2023
Securities Held-to-Maturity
Residential mortgage-backed securities	$	6,005	$	(94)	$	122,272	$	(17,406)	$	128,277	$	(17,500)
Total	$	6,005	$	(94)	$	122,272	$	(17,406)	$	128,277	$	(17,500)
Securities Available-for-Sale
State and political subdivisions	$	1,029	$	(1)	$	—	$	—	$	1,029	$	(1)
Residential mortgage-backed securities	16,992		(65)		238,053		(35,362)		255,045		(35,427)
Collateralized mortgage obligations	—		—		2,001		(200)		2,001		(200)
Corporate bonds	780		(1)		—		—		780		(1)
Total	$	18,801	$	(67)	$	240,054	$	(35,562)	$	258,855	$	(35,629)

Available-for-sale Securities, Allowance for Credit Loss Rollforward

The table below presents a rollforward by major security type for the six months ended June 30, 2024 and June 30, 2023 of the allowance for credit losses on securities available-for-sale.

(Dollars in thousands)	Corporate Bonds
Six months ended June 30, 2024
Securities Available-for-Sale
Beginning balance	$	(731)
Additions for securities for which no previous expected credit losses were recognized	(1)
Change in securities for which a previous expected credit loss was recognized	(49)
Ending balance	$	(781)
Six months ended June 30, 2023
Securities Available-for-Sale
Beginning balance	$	(1,140)
Additions for securities for which no previous expected credit losses were recognized	(2)
Change in securities for which a previous expected credit loss was recognized	(395)
Ending balance	$	(1,537)