Note 2 - Securities (Tables)

9 Months Ended

Sep. 30, 2023

Notes Tables

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

			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		Losses			Value
September 30, 2023
U.S. Government agency debt obligations	$	452,330,000	$	0	$	(68,251,000	)	$	384,079,000
Mortgage-backed securities		35,699,000		2,000		(7,685,000	)		28,016,000
Municipal general obligation bonds		166,922,000		33,000		(13,530,000	)		153,425,000
Municipal revenue bonds		30,004,000		14,000		(3,733,000	)		26,285,000
Other investments		500,000		0		0			500,000
	$	685,455,000	$	49,000	$	(93,199,000	)	$	592,305,000
December 31, 2022
U.S. Government agency debt obligations	$	453,836,000	$	0	$	(65,092,000	)	$	388,744,000
Mortgage-backed securities		38,002,000		19,000		(6,068,000	)		31,953,000
Municipal general obligation bonds		163,041,000		450,000		(9,058,000	)		154,433,000
Municipal revenue bonds		30,267,000		102,000		(3,063,000	)		27,306,000
Other investments		500,000		0		0			500,000
	$	685,646,000	$	571,000	$	(83,281,000	)	$	602,936,000

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
	Value		Loss		Value		Loss		Value		Loss
September 30, 2023
U.S. Government agency debt obligations	$	2,679,000	$	1,124,000	$	381,400,000	$	67,127,000	$	384,079,000	$	68,251,000
Mortgage-backed securities		26,231,000		7,558,000		1,604,000		127,000		27,835,000		7,685,000
Municipal general obligation bonds		33,136,000		2,992,000		115,872,000		10,538,000		149,008,000		13,530,000
Municipal revenue bonds		6,710,000		1,043,000		18,066,000		2,690,000		24,776,000		3,733,000
	$	68,756,000	$	12,717,000	$	516,942,000	$	80,482,000	$	585,698,000	$	93,199,000

	Less than 12 Months				12 Months or More				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Loss		Value		Loss		Value		Loss
December 31, 2022
U.S. Government agency debt obligations	$	53,019,000	$	5,713,000	$	335,725,000	$	59,379,000	$	388,744,000	$	65,092,000
Mortgage-backed securities		31,127,000		6,068,000		12,000		0		31,139,000		6,068,000
Municipal general obligation bonds		97,252,000		4,516,000		32,870,000		4,542,000		130,122,000		9,058,000
Municipal revenue bonds		12,532,000		1,141,000		10,609,000		1,922,000		23,141,000		3,063,000
	$	193,930,000	$	17,438,000	$	379,216,000	$	65,843,000	$	573,146,000	$	83,281,000

Investments Classified by Contractual Maturity Date [Table Text Block]

	Weighted
	Average		Amortized		Fair
	Yield		Cost		Value
Due in 2023	0.35	%	$	10,635,000	$	10,560,000
Due in 2024 through 2028	1.32			319,456,000		289,600,000
Due in 2029 through 2033	2.02			278,377,000		227,860,000
Due in 2034 and beyond	3.68			40,788,000		35,769,000
Mortgage-backed securities	2.18			35,699,000		28,016,000
Other investments	8.42			500,000		500,000
Total available for sale securities	1.78	%	$	685,455,000	$	592,305,000