Note 3 - Debt and Equity Securities (Tables)

9 Months Ended

Sep. 30, 2022

Notes Tables

Marketable Securities [Table Text Block]

	September 30, 2022
	Securities Available-For-Sale
	In Thousands
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Market Value
U.S. Treasury and other U.S. government agencies	$	14,658		—		1,180		13,478
U.S. Government-sponsored enterprises (GSEs)		180,264		—		31,410		148,854
Mortgage-backed securities		531,472		5		78,069		453,408
Asset-backed securities		41,256		—		1,526		39,730
Corporate bonds		2,500		—		121		2,379
Obligations of states and political subdivisions		224,965		—		43,662		181,303
	$	995,115		5		155,968		839,152

	December 31, 2021
	Securities Available-For-Sale
	In Thousands
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Market Value
U.S. Treasury and other U.S. government agencies	$	7,320		—		99		7,221
U.S. Government-sponsored enterprises (GSEs)		163,700		20		4,490		159,230
Mortgage-backed securities		465,588		2,726		6,537		461,777
Asset-backed securities		46,583		213		83		46,713
Corporate bonds		2,500		75		—		2,575
Obligations of states and political subdivisions		220,444		2,611		2,986		220,069
	$	906,135		5,645		14,195		897,585

Investments Classified by Contractual Maturity Date [Table Text Block]

	Available-For-Sale
	In Thousands
	Amortized Cost		Estimated Market Value
Due in one year or less	$	5,455	$	5,277
Due after one year through five years		85,654		78,157
Due after five years through ten years		271,526		226,693
Due after ten years		632,480		529,025
	$	995,115	$	839,152

Schedule of Unrealized Loss on Investments [Table Text Block]

	In Thousands, Except Number of Securities
	Less than 12 Months						12 Months or More						Total
September 30, 2022	Fair Value		Unrealized Losses		Number of Securities Included		Fair Value		Unrealized Losses		Number of Securities Included		Fair Value		Unrealized Losses
Available-for-Sale Securities:
U.S. Treasury and other U.S. government agencies	$	7,061	$	252		2	$	6,417	$	928		3	$	13,478	$	1,180
U.S. Government-sponsored enterprises (GSEs)		27,129		4,477		9		121,725		26,933		49		148,854		31,410
Mortgage-backed securities		229,613		30,715		152		222,875		47,354		98		452,488		78,069
Asset-backed securities		34,357		1,346		25		5,373		180		4		39,730		1,526
Corporate bonds		2,379		121		1		—		—		—		2,379		121
Obligations of states and political subdivisions		102,539		20,465		133		78,764		23,197		94		181,303		43,662
	$	403,078	$	57,376		322	$	435,154	$	98,592		248	$	838,232	$	155,968

	In Thousands, Except Number of Securities
	Less than 12 Months						12 Months or More						Total
December 31, 2021	Fair Value		Unrealized Losses		Number of Securities Included		Fair Value		Unrealized Losses		Number of Securities Included		Fair Value		Unrealized Losses
Available-for-Sale Securities:
U.S. Treasury and other U.S. government agencies	$	7,221	$	99		3	$	—	$	—		—	$	7,221	$	99
U.S. Government-sponsored enterprises (GSEs)		110,981		2,466		33		45,725		2,024		19		156,706		4,490
Mortgage-backed securities		317,211		4,644		96		54,692		1,893		33		371,903		6,537
Asset-backed securities		17,945		67		9		484		16		1		18,429		83
Corporate bonds		—		—		—		—		—		—		—		—
Obligations of states and political subdivisions		83,510		1,460		74		36,225		1,526		32		119,735		2,986
	$	536,868	$	8,736		215	$	137,126	$	5,459		85	$	673,994	$	14,195