Note 11 - Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2024

Notes Tables

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Fair Value Measurements at March 31, 2024 Using
	Quoted Prices in
	Active Markets		Significant Other		Significant
	for Identical		Observable Inputs		Unobservable
	Assets (Level 1)		(Level 2)		Inputs (Level 3)		Total
Assets Measured on a Recurring Basis:	(In Thousands)
Available for sale debt securities:
U.S. Treasury securities	$	493,969	$	-	$	-	$	493,969
Mortgage-backed securities		-		254,915		-		254,915
State and municipal securities		-		9,958		-		9,958
Corporate debt		-		315,086		-		315,086
Total available-for-sale debt securities		493,969		579,959		-		1,073,929
Total assets at fair value	$	493,969	$	579,959	$	-	$	1,073,929

	Fair Value Measurements at December 31, 2023 Using
	Quoted Prices in
	Active Markets		Significant Other		Significant
	for Identical		Observable Inputs		Unobservable
	Assets (Level 1)		(Level 2)		Inputs (Level 3)		Total
Assets Measured on a Recurring Basis:	(In Thousands)
Available for sale debt securities:
U.S. Treasury securities	$	340,807	$	-	$	-	$	340,807
Mortgage-backed securities		-		215,485		-		215,485
State and municipal securities		-		10,223		-		10,223
Corporate debt		-		326,808		6,860		333,668
Total available-for-sale debt securities		340,807		552,516		6,860		900,183
Total assets at fair value	$	340,807	$	552,516	$	6,860	$	900,183

Fair Value Measurements, Nonrecurring [Table Text Block]

	Fair Value Measurements at March 31, 2024 Using
	Quoted Prices in
	Active Markets		Significant Other		Significant
	for Identical		Observable		Unobservable
	Assets (Level 1)		Inputs (Level 2)		Inputs (Level 3)		Total
Assets Measured on a Nonrecurring Basis:	(In Thousands)
Loans individually evaluated	$	-	$	-	$	81,871	$	81,871
Other real estate owned and repossessed assets		-		-		490		490
Total assets at fair value	$	-	$	-	$	82,361	$	82,361

	Fair Value Measurements at December 31, 2023 Using
	Quoted Prices in
	Active Markets		Significant Other		Significant
	for Identical		Observable		Unobservable
	Assets (Level 1)		Inputs (Level 2)		Inputs (Level 3)		Total
Assets Measured on a Nonrecurring Basis:	(In Thousands)
Loans individually evaluated	$	-	$	-	$	70,735	$	70,735
Other real estate owned		-		-		995		995
Total assets at fair value	$	-	$	-	$	71,730	$	71,730

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

	For the period ended March 31,
	2024			2023
	Available-for-sale Securities			Available-for-sale Securities
	(In Thousands)
Fair value, beginning of period	$	6,860		$	10,860
Transfers into Level 3		-			-
Total realized gains included in income		-			-
Changes in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at period-end		(1,329	)		160
Purchases		-			-
Transfers out of Level 3		(5,531	)		(4,160	)
Fair value, end of period	$	-		$	6,860

Fair Value, by Balance Sheet Grouping [Table Text Block]

	March 31, 2024				December 31, 2023
	Carrying				Carrying
	Amount		Fair Value		Amount		Fair Value
	(In Thousands)
Financial Assets:
Level 1 Inputs:
Cash and cash equivalents	$	1,280,274	$	1,280,274	$	2,030,513	$	2,030,513
Held to maturity U.S. Treasury securities		393,932		368,868		508,985		484,267
Level 2 Inputs:
Federal funds sold		170,625		170,625		100,575		100,575
Held to maturity debt securities		473,514		416,152		473,429		422,674
Mortgage loans held for sale		7,592		7,592		5,071		5,071
Restricted equity securities		11,300		11,300		10,226		10,226
Level 3 Inputs:
Held to maturity debt securities		250		250		250		250
Loans, net		11,642,933		11,195,399		11,505,512		11,032,819
Financial Liabilities:
Level 2 Inputs:
Deposits	$	12,751,448	$	12,743,505	$	13,273,511	$	13,266,640
Federal funds purchased		1,345,328		1,345,328		1,256,724		1,256,724
Other borrowings		64,737		58,337		64,735		58,083