Note 4 - Securities (Tables)

9 Months Ended

Sep. 30, 2023

Notes Tables

Unrealized Gain (Loss) on Investments [Table Text Block]

			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gain		Loss			Value
September 30, 2023	(In Thousands)
Debt Securities Available-for-Sale
U.S. Treasury Securities	$	280,807	$	7	$	(96	)	$	280,718
Mortgage-backed securities		251,001		-		(35,760	)		215,241
State and municipal securities		12,762		1		(1,570	)		11,193
Corporate debt		375,673		-		(48,023	)		327,650
Total	$	920,243	$	8	$	(85,449	)	$	834,802
Debt Securities Held-to-Maturity
U.S. Treasury Securities	$	558,196	$	-	$	(35,014	)	$	523,182
Mortgage-backed securities		477,646		-		(74,928	)		402,718
State and municipal securities		8,057		-		(951	)		7,106
Total	$	1,043,899	$	-	$	(110,893	)	$	933,006
December 31, 2022
Debt Securities Available-for-Sale
U.S. Treasury Securities	$	3,002	$	-	$	(33	)	$	2,969
Government Agency Securities		9		-		-			9
Mortgage-backed securities		282,480		5		(32,782	)		249,703
State and municipal securities		15,205		1		(1,597	)		13,609
Corporate debt		406,680		-		(28,155	)		378,525
Total	$	707,376	$	6	$	(62,567	)	$	644,815
Debt Securities Held-to-Maturity
U.S. Treasury Securities	$	507,151	$	-	$	(36,197	)	$	470,954
Mortgage-backed securities		518,929		7		(60,960	)		457,976
State and municipal securities		8,041		-		(1,018	)		7,023
Total	$	1,034,121	$	7	$	(98,175	)	$	935,953

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

	September 30, 2023				December 31, 2022
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
	(In Thousands)
Debt securities available-for-sale
Due within one year	$	292,131	$	291,740	$	24,712	$	24,432
Due from one to five years		66,668		63,623		58,554		57,092
Due from five to ten years		307,443		261,919		338,630		311,100
Due after ten years		3,000		2,279		3,000		2,488
Mortgage-backed securities		251,001		215,241		282,480		249,703
	$	920,243	$	834,802	$	707,376	$	644,815
Debt securities held-to-maturity
Due within one year	$	309,311	$	304,931	$	250	$	250
Due from one to five years		128,708		115,557		386,465		366,095
Due from five to ten years		128,234		109,800		128,477		111,632
Mortgage-backed securities		477,646		402,718		518,929		457,976
	$	1,043,899	$	933,006	$	1,034,121	$	935,953

Gain (Loss) on Securities [Table Text Block]

	Less Than Twelve Months					Twelve Months or More					Total
	Gross					Gross					Gross
	Unrealized					Unrealized					Unrealized
	Losses			Fair Value		Losses			Fair Value		Losses			Fair Value
	(In Thousands)
September 30, 2023
Debt Securities available-for-sale
U.S. Treasury Securities	$	(96	)	$	231,360	$	-		$	-	$	(96	)	$	231,360
Mortgage-backed securities		(33	)		1,137		(35,727	)		214,104		(35,760	)		215,241
State and municipal securities		-			-		(1,570	)		10,462		(1,570	)		10,462
Corporate debt		(772	)		13,660		(47,251	)		305,631		(48,023	)		319,291
Total	$	(901	)	$	246,157	$	(84,548	)	$	530,197	$	(85,449	)	$	776,354
Debt Securities held-to-maturity
U.S. Treasury Securities	$	(6	)	$	49,669	$	(35,008	)	$	473,513	$	(35,014	)	$	523,182
Mortgage-backed securities		(38	)		846		(74,890	)		398,551		(74,928	)		399,396
State and municipal securities		-			-		(951	)		6,856		(951	)		6,856
Total	$	(44	)	$	50,515	$	(110,849	)	$	878,920	$	(110,893	)	$	929,434
December 31, 2022
Debt Securities available-for-sale
U.S. Treasury Securities	$	(33	)	$	2,969	$	-		$	-	$	(33	)	$	2,969
Government Agency Securities		-			9		-			-		-			9
Mortgage-backed securities		(3,473	)		60,234		(29,309	)		189,109		(32,782	)		249,343
State and municipal securities		(186	)		5,283		(1,411	)		7,880		(1,597	)		13,163
Corporate debt		(18,566	)		304,254		(9,589	)		63,411		(28,155	)		367,666
Total	$	(22,258	)	$	372,749	$	(40,309	)	$	260,400	$	(62,567	)	$	633,149
Debt Securities held-to-maturity
U.S. Treasury Securities	$	(12,662	)	$	295,383	$	(23,537	)	$	175,570	$	(36,197	)	$	470,953
Mortgage-backed securities		(31,367	)		278,746		(29,592	)		174,842		(60,960	)		453,588
State and municipal securities		(544	)		4,443		(474	)		2,330		(1,018	)		6,773
Total	$	(44,573	)	$	578,572	$	(53,603	)	$	352,742	$	(98,175	)	$	931,314

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

	Nine Months Ended September 30,
	2023		2022
	(In Thousands)
Sale proceeds	$	-	$	75,036
Gross realized gains	$	-	$	-
Gross realized losses		-		(6,168	)
Net realized gain (loss)	$	-	$	(6,168	)