Note 3 - Investment Securities (Tables)

9 Months Ended

Sep. 30, 2022

Notes Tables

Debt Securities, Available-for-sale and Held-to-maturity [Table Text Block]

	At September 30, 2022
			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		Losses			Value
	(In thousands)
Debt securities available for sale
Agency residential mortgage-backed securities ("MBS")	$	326,577	$	3	$	(29,891	)	$	296,689
Securities of U.S. Government sponsored entities		289,105		-		(16,580	)		272,525
Obligations of states and political subdivisions		85,178		50		(4,241	)		80,987
Corporate securities		2,491,591		1,085		(354,168	)		2,138,508
Collateralized loan obligations		1,596,730		497		(9,605	)		1,587,622
Total debt securities available for sale		4,789,181		1,635		(414,485	)		4,376,331
Debt securities held to maturity
Agency residential MBS		112,371		20		(8,278	)		104,113
Obligations of states and political subdivisions		103,749		29		(1,654	)		102,124
Corporate securities		720,154		-		(47,929	)		672,225
Total debt securities held to maturity		936,274		49		(57,861	)		878,462
Total	$	5,725,455	$	1,684	$	(472,346	)	$	5,254,793

	At December 31, 2021
			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		Losses			Value
	(In thousands)
Debt securities available for sale
Agency residential MBS	$	399,997	$	11,766	$	(37	)	$	411,726
Securities of U.S. Government entities		119		-		-			119
Obligations of states and political subdivisions		90,107		3,842		(29	)		93,920
Corporate securities		2,692,792		63,573		(9,630	)		2,746,735
Collateralized loan obligations		1,385,331		1,743		(719	)		1,386,355
Total debt securities available for sale		4,568,346		80,924		(10,415	)		4,638,855
Debt securities held to maturity
Agency residential MBS		148,390		3,114		(37	)		151,467
Obligations of states and political subdivisions		158,013		3,082		-			161,095
Total debt securities held to maturity		306,403		6,196		(37	)		312,562
Total	$	4,874,749	$	87,120	$	(10,452	)	$	4,951,417

Investments Classified by Contractual Maturity Date [Table Text Block]

	At September 30, 2022
	Debt Securities Available				Debt Securities Held
	for Sale				to Maturity
	Amortized		Fair		Amortized		Fair
	Cost		Value		Cost		Value
	(In thousands)
Maturity in years:
1 year or less	$	331,756	$	329,956	$	14,686	$	14,634
Over 1 to 5 years		557,420		523,563		170,979		165,738
Over 5 to 10 years		2,823,019		2,482,869		638,238		593,977
Over 10 years		750,409		743,254		-		-
Subtotal		4,462,604		4,079,642		823,903		774,349
MBS		326,577		296,689		112,371		104,113
Total	$	4,789,181	$	4,376,331	$	936,274	$	878,462

	At December 31, 2021
	Debt Securities Available				Debt Securities Held
	for Sale				to Maturity
	Amortized		Fair		Amortized		Fair
	Cost		Value		Cost		Value
	(In thousands)
Maturity in years:
1 year or less	$	306,333	$	309,257	$	15,836	$	15,941
Over 1 to 5 years		707,062		738,057		125,001		127,539
Over 5 to 10 years		2,320,559		2,347,242		17,176		17,615
Over 10 years		834,395		832,573		-		-
Subtotal		4,168,349		4,227,129		158,013		161,095
MBS		399,997		411,726		148,390		151,467
Total	$	4,568,346	$	4,638,855	$	306,403	$	312,562

Schedule of Unrealized Loss on Investments [Table Text Block]

	Debt Securities Available for Sale
	At September 30, 2022
	No. of		Less than 12 months					No. of		12 months or longer					No. of		Total
	Investment				Unrealized			Investment				Unrealized			Investment				Unrealized
	Positions		Fair Value		Losses			Positions		Fair Value		Losses			Positions		Fair Value		Losses
	($ in thousands)
Agency residential MBS		114	$	295,984	$	(29,890	)		2	$	39	$	(1	)		116	$	296,023	$	(29,891	)
Securities of U.S. Government sponsored entities		19		272,525		(16,580	)		-		-		-			19		272,525		(16,580	)
Obligations of states and political subdivisions		63		66,998		(4,148	)		3		1,309		(93	)		66		68,307		(4,241	)
Corporate securities		156		1,787,045		(256,786	)		36		323,597		(97,382	)		192		2,110,642		(354,168	)
Collateralized loan obligations		58		535,175		(8,768	)		16		151,448		(837	)		74		686,623		(9,605	)
Total		410	$	2,957,727	$	(316,172	)		57	$	476,393	$	(98,313	)		467	$	3,434,120	$	(414,485	)

	Debt Securities Held to Maturity
	At September 30, 2022
	No. of		Less than 12 months					No. of		12 months or longer					No. of		Total
	Investment				Unrecognized			Investment				Unrecognized			Investment				Unrecognized
	Positions		Fair Value		Losses			Positions		Fair Value		Losses			Positions		Fair Value		Losses
	($ in thousands)
Agency residential MBS		93	$	102,485	$	(8,183	)		3	$	710	$	(95	)		96	$	103,195	$	(8,278	)
Obligations of states and political subdivisions		99		82,394		(1,654	)		-		-		-			99		82,394		(1,654	)
Corporate securities		49		657,226		(47,929	)		-		-		-			49		657,226		(47,929	)
Total		241	$	842,105	$	(57,766	)		3	$	710	$	(95	)		244	$	842,815	$	(57,861	)

	Debt Securities Available for Sale
	At December 31, 2021
	No. of		Less than 12 months					No. of		12 months or longer					No. of		Total
	Investment				Unrealized			Investment				Unrealized			Investment				Unrealized
	Positions		Fair Value		Losses			Positions		Fair Value		Losses			Positions		Fair Value		Losses
	($ in thousands)
Agency residential MBS		7	$	8,900	$	(37	)		2	$	47	$	-			9	$	8,947	$	(37	)
Securities of U.S. Government entities		-		-		-			1		119		-			1		119		-
Obligations of states and political subdivisions		6		2,859		(27	)		2		669		(2	)		8		3,528		(29	)
Corporate securities		56		691,555		(9,630	)		-		-		-			56		691,555		(9,630	)
Collateralized loan obligations		19		208,199		(521	)		8		51,523		(198	)		27		259,722		(719	)
Total		88	$	911,513	$	(10,215	)		13	$	52,358	$	(200	)		101	$	963,871	$	(10,415	)

	Debt Securities Held to Maturity
	At December 31, 2021
	No. of		Less than 12 months					No. of		12 months or longer					No. of		Total
	Investment				Unrecognized			Investment				Unrecognized			Investment				Unrecognized
	Positions		Fair Value		Losses			Positions		Fair Value		Losses			Positions		Fair Value		Losses
	($ in thousands)
Agency residential MBS		1	$	542	$	(19	)		3	$	530	$	(18	)		4	$	1,072	$	(37	)
Total		1	$	542	$	(19	)		3	$	530	$	(18	)		4	$	1,072	$	(37	)

Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Table Text Block]

	For the Nine Months Ended September 30,
	2022		2021
	(In thousands)
Allowance for credit losses:
Beginning balance	$	7	$	9
Provision (Reversal)		-		(2	)
Chargeoffs		-		-
Recoveries		-		-
Total ending balance	$	7	$	7

Debt Securities, Held-to-Maturity, Credit Quality Indicator [Table Text Block]

	Credit Risk Profile by Credit Rating
	At September 30, 2022
	AAA/AA/A		BBB+		B-		Not Rated		Total
	(In thousands)
Agency residential MBS	$	111,837	$	-	$	487	$	47	$	112,371
Obligations of states and political subdivisions		103,484		-		-		265		103,749
Corporate securities		466,906		253,248		-		-		720,154
Total	$	682,227	$	253,248	$	487	$	312	$	936,274

Interest Income from Investments [Table Text Block]

	For the Three Months				For the Nine Months
	Ended September 30,
	2022		2021		2022		2021
	(In thousands)
Taxable	$	44,461	$	26,674	$	105,286	$	78,564
Tax-exempt from federal income tax		1,391		1,978		4,568		6,638
Total interest income from investment securities	$	45,852	$	28,652	$	109,854	$	85,202