Note 4 - Investment Securities (Tables)

9 Months Ended

Sep. 30, 2024

Notes Tables

Debt Securities, Available-for-Sale [Table Text Block]

	September 30, 2024
	Amortized		Unrealized		Unrealized			Allowance for		Fair
(dollars in thousands)	Cost		Gains		Losses			Credit Losses		Value
Available-for-sale
U.S. Treasury and agencies	$	739	$	2	$	(2	)	$	—	$	739
Mortgage backed securities
Residential agency		488,915		2		(74,529	)		—		414,388
Commercial		1,460		—		(59	)		—		1,401
Asset backed securities		20		—		—			—		20
Corporate bonds		57,988		—		(8,533	)		—		49,455
Total available-for-sale investment securities		549,122		4		(83,123	)		—		466,003
Held-to-maturity
Obligations of state and political agencies		122,717		—		(9,124	)		81		113,593
Mortgage backed securities
Residential agency		159,333		—		(23,064	)		56		136,269
Total held-to-maturity investment securities		282,050		—		(32,188	)		137		249,862
Total investment securities	$	831,172	$	4	$	(115,311	)	$	137	$	715,865

	December 31, 2023
	Amortized		Unrealized		Unrealized			Allowance for		Fair
(dollars in thousands)	Cost		Gains		Losses			Credit Losses		Value
Available-for-sale
U.S. Treasury and agencies	$	1,119	$	4	$	(3	)		—	$	1,120
Mortgage backed securities
Residential agency		524,140		1		(88,547	)		—		435,594
Commercial		1,476		—		(123	)		—		1,353
Asset backed securities		26		—		(1	)		—		25
Corporate bonds		57,993		—		(9,349	)		—		48,644
Total available-for-sale investment securities		584,754		5		(98,023	)		—		486,736
Held-to-maturity
Obligations of state and political agencies		129,603		—		(12,613	)		114		116,990
Mortgage backed securities
Residential agency		170,125		—		(28,498	)		99		141,627
Total held-to-maturity investment securities		299,728		—		(41,111	)		213		258,617
Total investment securities	$	884,482	$	5	$	(139,134	)	$	213	$	745,353

Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block]

			September 30, 2024
			Less than 12 Months					Over 12 Months					Total
	Number of		Unrealized			Fair		Unrealized			Fair		Unrealized			Fair
(dollars in thousands)	Holdings		Losses			Value		Losses			Value		Losses			Value
Available-for-sale
U.S. Treasury and agencies		1	$	(2	)	$	370	$	—		$	—	$	(2	)	$	370
Mortgage backed securities
Residential agency		108		—			—		(74,529	)		414,315		(74,529	)		414,315
Commercial		1		—			—		(59	)		1,401		(59	)		1,401
Asset backed securities		3		—			—		—			20		—			20
Corporate bonds		12		—			—		(8,533	)		49,455		(8,533	)		49,455
Total available-for-sale investment securities		125	$	(2	)	$	370	$	(83,121	)	$	465,191	$	(83,123	)	$	465,561

			December 31, 2023
			Less than 12 Months					Over 12 Months					Total
	Number of		Unrealized			Fair		Unrealized			Fair		Unrealized			Fair
(dollars in thousands)	Holdings		Losses			Value		Losses			Value		Losses			Value
Available-for-sale
U.S. Treasury and agencies		1	$	(3	)	$	489	$	—		$	—	$	(3	)	$	489
Mortgage backed securities
Residential agency		112		—			43		(88,547	)		435,505		(88,547	)		435,548
Commercial		1		—			—		(123	)		1,353		(123	)		1,353
Asset backed securities		3		—			—		(1	)		25		(1	)		25
Corporate bonds		12		—			—		(9,349	)		48,644		(9,349	)		48,644
Total available-for-sale investment securities		129	$	(3	)	$	532	$	(98,020	)	$	485,527	$	(98,023	)	$	486,059

Investments Classified by Contractual Maturity Date [Table Text Block]

	Held-to-maturity				Available-for-sale
	Carrying		Fair		Amortized		Fair
(dollars in thousands)	Value		Value		Cost		Value
Due within one year or less	$	8,282	$	8,203	$	—	$	—
Due after one year through five years		56,385		53,122		1,838		1,778
Due after five years through ten years		48,042		43,323		57,992		49,460
Due after 10 years		10,008		8,945		377		377
		122,717		113,593		60,207		51,615
Mortgage-backed securities
Residential agency		159,333		136,269		488,915		414,388
Total investment securities	$	282,050	$	249,862	$	549,122	$	466,003

Federal Home Loan Bank, Advances [Table Text Block]

	September 30,		December 31,
(dollars in thousands)	2024		2023
Federal Reserve	$	4,623	$	4,623
FHLB		13,757		16,566