Note 2 - Securities (Tables)

3 Months Ended

Mar. 31, 2024

Notes Tables

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

			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
(Dollars in thousands)	Cost		Gains		Losses			Value
March 31, 2024
U.S. Government agency debt obligations	$	438,662	$	0	$	(52,953	)	$	385,709
Mortgage-backed securities		34,059		10		(6,287	)		27,782
Municipal general obligation bonds		172,279		1,244		(6,891	)		166,632
Municipal revenue bonds		30,708		151		(2,329	)		28,530
Other investments		500		0		0			500
	$	676,208	$	1,405	$	(68,460	)	$	609,153
December 31, 2023
U.S. Government agency debt obligations	$	442,496	$	0	$	(52,000	)	$	390,496
Mortgage-backed securities		35,168		20		(5,715	)		29,473
Municipal general obligation bonds		172,126		1,924		(6,190	)		167,860
Municipal revenue bonds		30,708		262		(2,207	)		28,763
Other investments		500		0		0			500
	$	680,998	$	2,206	$	(66,112	)	$	617,092

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

	Less than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(Dollars in thousands)	Value		Loss		Value		Loss		Value		Loss
March 31, 2024
U.S. Government agency debt obligations	$	0	$	0	$	385,709	$	52,953	$	385,709	$	52,953
Mortgage-backed securities		201		3		27,089		6,284		27,290		6,287
Municipal general obligation bonds		20,393		189		100,489		6,702		120,882		6,891
Municipal revenue bonds		1,141		10		21,061		2,319		22,202		2,329
Other investments		0		0		0		0		0		0
	$	21,735	$	202	$	534,348	$	68,258	$	556,083	$	68,460

	Less than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(Dollars in thousands)	Value		Loss		Value		Loss		Value		Loss
December 31, 2023
U.S. Government agency debt obligations	$	0	$	0	$	390,496	$	52,000	$	390,496	$	52,000
Mortgage-backed securities		114		0		28,749		5,715		28,863		5,715
Municipal general obligation bonds		1,109		6		106,171		6,184		107,280		6,190
Municipal revenue bonds		1,506		8		20,602		2,199		22,108		2,207
Other investments		0		0		0		0		0		0
	$	2,729	$	14	$	546,018	$	66,098	$	548,747	$	66,112

Investments Classified by Contractual Maturity Date [Table Text Block]

	Amortized		Fair
(Dollars in thousands)	Cost		Value
Due in 2024	$	53,520	$	52,568
Due in 2025 through 2029		329,740		301,553
Due in 2030 through 2034		227,431		196,189
Due in 2035 and beyond		30,958		30,561
Mortgage-backed securities		34,059		27,782
Other investments		500		500
Total available for sale securities	$	676,208	$	609,153