Note 2 - Securities (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

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

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
2021
U.S. Government agency debt obligations	$	398,874,000	$	266,000	$	(8,769,000	)	$	390,371,000
Mortgage-backed securities		41,906,000		549,000		(652,000	)		41,803,000
Municipal general obligation bonds		133,894,000		4,092,000		(392,000	)		137,594,000
Municipal revenue bonds		22,289,000		331,000		(145,000	)		22,475,000
Other investments		500,000		0		0			500,000
	$	597,463,000	$	5,238,000	$	(9,958,000	)	$	592,743,000
2020
U.S. Government agency debt obligations	$	242,522,000	$	516,000	$	(897,000	)	$	242,141,000
Mortgage-backed securities		23,869,000		1,021,000		0			24,890,000
Municipal general obligation bonds		101,991,000		5,833,000		0			107,824,000
Municipal revenue bonds		11,521,000		473,000		(2,000	)		11,992,000
Other investments		500,000		0		0			500,000
	$	380,403,000	$	7,843,000	$	(899,000	)	$	387,347,000

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

	Less than 12 Months				12 Months or More				Total
Description of Securities	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
2021
U.S. Government agency debt obligations	$	274,287,000	$	5,274,000	$	110,053,000	$	3,495,000	$	384,340,000	$	8,769,000
Mortgage-backed securities		23,184,000		652,000		24,000		0		23,208,000		652,000
Municipal general obligation bonds		40,748,000		392,000		0		0		40,748,000		392,000
Municipal revenue bonds		12,843,000		137,000		414,000		8,000		13,257,000		145,000
Other investments		0		0		0		0		0		0
	$	351,062,000	$	6,455,000	$	110,491,000	$	3,503,000	$	461,553,000	$	9,958,000
2020
U.S. Government agency debt obligations	$	118,650,000	$	897,000	$	0	$	0	$	118,650,000	$	897,000
Mortgage-backed securities		0		0		0		0		0		0
Municipal general obligation bonds		0		0		0		0		0		0
Municipal revenue bonds		423,000		2,000		0		0		423,000		2,000
Other investments		0		0		0		0		0		0
	$	119,073,000	$	899,000	$	0	$	0	$	119,073,000	$	899,000

Investments Classified by Contractual Maturity Date [Table Text Block]

	Weighted Average Yield			Amortized Cost		Fair Value
Due in one year or less		1.92	%	$	11,406,000	$	11,458,000
Due from one to five years		0.96			185,889,000		184,788,000
Due from five to ten years		1.56			288,599,000		285,609,000
Due after ten years		1.99			69,163,000		68,585,000
Mortgage-backed securities		1.85			41,906,000		41,803,000
Other investments		3.75			500,000		500,000
		1.45	%	$	597,463,000	$	592,743,000