Note 3. Investment Securities (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Amortized cost and fair value of HTM and AFS investment securities

			Allowance		Gross		Gross
	Amortized		for Credit		Unrealized		Unrealized		Fair
	Cost		(Losses)		Gains		(Losses)		Value
	(dollars in thousands)
December 31, 2023:
Securities HTM:
Municipal securities	$	682,657	$	(202)	$	33,385	$	(36,639)	$	679,201
Other securities		1,050		(1)		44		(15)		1,078
	$	683,707	$	(203)	$	33,429	$	(36,654)	$	680,279
Securities AFS:
U.S. treasuries and govt. sponsored agency securities	$	17,399	$	—	$	12	$	(2,438)	$	14,973
Residential mortgage-backed and related securities		65,168		—		—		(5,972)		59,196
Municipal securities		206,566		—		11		(35,590)		170,987
Asset-backed securities		15,261		—		167		(5)		15,423
Other securities		44,239		(989)		—		(4,174)		39,076
	$	348,633	$	(989)	$	190	$	(48,179)	$	299,655

* HTM securities shown on the balance sheet of $683.5 million represent amortized cost of $683.7 million, net of allowance for credit losses of $203 thousand as of December 31, 2023.

			Allowance		Gross		Gross
	Amortized		for Credit		Unrealized		Unrealized		Fair
	Cost		(Losses)		Gains		(Losses)		Value
	(dollars in thousands)
December 31, 2022:
Securities HTM:
Municipal securities	$	586,272	$	(180)	$	5,292	$	(56,798)	$	534,586
Other securities		1,050		—		—		—		1,050
	$	587,322	$	(180)	$	5,292	$	(56,798)	$	535,636
Securities AFS:
U.S. govt. sponsored agency securities	$	19,745	$	—	$	19	$	(2,783)	$	16,981
Residential mortgage-backed and related securities		73,438		—		—		(7,223)		66,215
Municipal securities		239,812		—		66		(46,700)		193,178
Asset-backed securities		18,885		—		48		(205)		18,728
Other securities		48,631		—		27		(2,800)		45,858
	$	400,511	$	—	$	160	$	(59,711)	$	340,960

* HTM securities shown on the balance sheet of $587.1 million represent amortized cost of $587.3 million, net of allowance for credit losses of $180 thousand as of December 31, 2022.

Securities have been in a continuous unrealized loss position

	Less than 12 Months				12 Months or More				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
	(dollars in thousands)
December 31, 2023:
Securities HTM:
Municipal securities	$	1,320	$	(11)	$	289,891	$	(36,628)	$	291,211	$	(36,639)
Other securities		535		(15)		—		—		535		(15)
	$	1,855	$	(26)	$	289,891	$	(36,628)	$	291,746	$	(36,654)
Securities AFS:
U.S. treasuries and govt. sponsored agency securities	$	—	$	—	$	14,018	$	(2,438)	$	14,018	$	(2,438)
Residential mortgage-backed and related securities		—		—		59,118		(5,972)		59,118		(5,972)
Municipal securities		283		(2)		169,876		(35,588)		170,159		(35,590)
Asset-backed securities		—		—		3,804		(5)		3,804		(5)
Other securities		3,805		(393)		35,271		(3,781)		39,076		(4,174)
	$	4,088	$	(395)	$	282,087	$	(47,784)	$	286,175	$	(48,179)

	Less than 12 Months				12 Months or More				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
	(dollars in thousands)
December 31, 2022:
Securities HTM:
Municipal securities	$	347,651	$	(56,798)	$	—	$	—	$	347,651	$	(56,798)
Securities AFS:
U.S. treasuries and govt. sponsored agency securities	$	5,138	$	(326)	$	10,591	$	(2,457)	$	15,729	$	(2,783)
Residential mortgage-backed and related securities		48,469		(3,327)		17,690		(3,896)		66,159		(7,223)
Municipal securities		178,172		(42,661)		9,809		(4,039)		187,981		(46,700)
Asset-backed securities		13,684		(205)		—		—		13,684		(205)
Other securities		35,206		(2,404)		4,122		(396)		39,328		(2,800)
	$	280,669	$	(48,923)	$	42,212	$	(10,788)	$	322,881	$	(59,711)

Activity in allowance for credit losses for HTM and AFS securities by major security

	Year Ended December 31, 2023								Year Ended December 31, 2022
	Securities HTM						Securities AFS		Securities HTM		Securities AFS
	Municipal		Other				Corporate		Municipal		Corporate
	securities		securities		Total		securities		securities		securities
Allowance for credit losses:
Beginning balance	$	180	$	—	$	180	$	—	$	198	$	—
Provision for credit loss expense		22		1		23		989		(18)		—
Balance, ending	$	202	$	1	$	203	$	989	$	180	$	—

Realized gain (loss) on investments

	2023		2022		2021
	(dollars in thousands)
Proceeds from sales of securities	$	30,568	$	111,375	$	23,874
Gross gains from sales of securities		56		—		—
Gross losses from sales of securities		(507)		—		(88)

Investments classified by maturity date

	Amortized Cost		Fair Value
	(dollars in thousands)
Securities HTM:
Due in one year or less	$	1,876	$	1,867
Due after one year through five years		27,293		29,060
Due after five years		654,538		649,352
	$	683,707	$	680,279
Securities AFS:
Due in one year or less	$	968	$	964
Due after one year through five years		16,819		14,815
Due after five years		250,417		209,257
		268,204		225,036
Residential mortgage-backed and related securities		65,168		59,196
Asset-backed securities		15,261		15,423
	$	348,633	$	299,655

Schedule of investment in callable securities

	Amortized Cost		Fair Value
	(dollars in thousands)
Securities HTM:
Municipal securities	$	261,340	$	257,714
Securities AFS:
Municipal securities		205,165		169,604
Other securities		43,283		38,133
	$	248,448	$	207,737