Note 3 - Debt and Equity Securities (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Marketable Securities [Table Text Block]

	Securities Available-For-Sale
	In Thousands
			Gross Unrealized		Gross Unrealized		Estimated Market
	Amortized Cost		Gains		Losses		Value
Government-sponsored enterprises (GSEs)	$	59,735		48		204		59,579
Mortgage-backed securities		265,648		2,300		635		267,313
Asset-backed securities		27,531		1		303		27,229
Obligations of states and political subdivisions		67,293		559		828		67,024
	$	420,207		2,908		1,970		421,145

	Securities Available-For-Sale
	In Thousands
			Gross Unrealized		Gross Unrealized		Estimated Market
	Amortized Cost		Gains		Losses		Value
Government-sponsored enterprises (GSEs)	$	71,446		—		2,979		68,467
Mortgage-backed securities		152,375		9		4,874		147,510
Asset-backed securities		22,534		10		844		21,700
Obligations of states and political subdivisions		49,328		22		1,775		47,575
	$	295,683		41		10,472		285,252

Investments Classified by Contractual Maturity Date [Table Text Block]

	In Thousands
Securities Available-For-Sale	Amortized Cost		Estimated Market Value
Due in one year or less	$	472		471
Due after one year through five years		18,332		18,319
Due after five years through ten years		56,626		56,622
Due after ten years		51,598		51,191
		127,028		126,603
Mortgage and asset-backed securities		293,179		294,542
	$	420,207		421,145

Schedule of Realized Gain (Loss) [Table Text Block]

	In Thousands
	2019			2018			2017
Gross proceeds	$	37,325			39,857			35,555
Gross realized gains	$	75			102			76
Gross realized losses		(343	)		(752	)		(251	)
Net realized gains (losses)	$	(268	)		(650	)		(175	)

Schedule of Unrealized Loss on Investments [Table Text Block]

	In Thousands, Except Number of Securities
	Less than 12 Months						12 Months or More						Total
					Number of						Number of
			Unrealized		Securities				Unrealized		Securities				Unrealized
2019	Fair Value		Losses		Included		Fair Value		Losses		Included		Fair Value		Losses
Available-for-Sale Securities:
Debt securities:
GSEs	$	16,507	$	114		5	$	24,658	$	90		9	$	41,165	$	204
Mortgage-backed securities		45,862		182		21		56,917		453		52		102,779		635
Asset-backed securities		17,807		161		10		7,317		142		4		25,124		303
Obligations of states and political subdivisions		30,423		783		26		3,858		45		10		34,281		828
	$	110,599	$	1,240		62	$	92,750	$	730		75	$	203,349	$	1,970

	In Thousands, Except Number of Securities
	Less than 12 Months						12 Months or More						Total
					Number of						Number of
			Unrealized		Securities				Unrealized		Securities				Unrealized
2018	Fair Value		Losses		Included		Fair Value		Losses		Included		Fair Value		Losses
Available-for-Sale Securities:
Debt securities:
GSEs	$	—	$	—		—	$	68,467	$	2,979		28	$	68,467	$	2,979
Mortgage-backed securities		8,651		64		10		137,457		4,810		94		146,108		4,874
Asset-backed securities		—		—		—		20,597		844		14		20,597		844
Obligations of states and political subdivisions		4,064		26		6		39,841		1,749		94		43,905		1,775
	$	12,715	$	90		16	$	266,362	$	10,382		230	$	279,077	$	10,472