Note 8 - Investment Securities (Tables)

6 Months Ended

Jun. 30, 2023

Notes Tables

Schedule of Available-for-Sale Securities Reconciliation [Table Text Block]

	June 30, 2023
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	272,485	$	—	$	447	$	272,038
U.S. government agency entities		55,485		190		132		55,543
U.S. government sponsored entities		33,709		—		95		33,614
Mortgage-backed securities		943,270		46		121,072		822,244
Collateralized mortgage obligations		33,051		—		3,548		29,503
Corporate debt securities		268,616		6		16,694		251,928
Foreign debt securities		22,741		3		293		22,451
Total	$	1,629,357	$	245	$	142,281	$	1,487,321

	December 31, 2022
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	241,611	$	—	$	1,111	$	240,500
U.S. government agency entities		63,347		384		121		63,610
U.S. government sponsored entities		30,000		—		—		30,000
Mortgage-backed securities		993,883		194		126,983		867,094
Collateralized mortgage obligations		34,552		—		3,491		31,061
Corporate debt securities		258,780		112		17,809		241,083
Total	$	1,622,173	$	690	$	149,515	$	1,473,348

Investments Classified by Contractual Maturity Date [Table Text Block]

	June 30, 2023
	Securities Available-For-Sale
	Amortized Cost		Fair Value
	(In thousands)
Due in one year or less	$	355,228	$	353,895
Due after one year through five years		239,805		224,105
Due after five years through ten years		165,000		154,597
Due after ten years		869,324		754,724
Total	$	1,629,357	$	1,487,321

Schedule of Unrealized Loss on Investments [Table Text Block]

	June 30, 2023
	Less than 12 Months				12 Months or Longer				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	272,038	$	447	$	—	$	—	$	272,038	$	447
U.S. government agency entities		15,885		8		1,542		124		17,427		132
U.S. government sponsored entities		33,614		95		—		—		33,614		95
Mortgage-backed securities		122,348		6,039		689,736		115,033		812,084		121,072
Collateralized mortgage obligations		23,251		1,662		6,252		1,886		29,503		3,548
Corporate debt securities		122,562		2,438		119,360		14,256		241,922		16,694
Foreign debt securities		9,707		293		—		—		9,707		293
Total	$	599,405	$	10,982	$	816,890	$	131,299	$	1,416,295	$	142,281

	December 31, 2022
	Less than 12 Months				12 Months or Longer				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	240,500	$	1,111	$	—	$	—	$	240,500	$	1,111
U.S. government agency entities		—		—		1,806		121		1,806		121
Mortgage-backed securities		394,123		33,042		452,739		93,941		846,862		126,983
Collateralized mortgage obligations		24,427		1,614		6,634		1,877		31,061		3,491
Corporate debt securities		109,995		3,256		100,977		14,553		210,972		17,809
Total	$	769,045	$	39,023	$	562,156	$	110,492	$	1,331,201	$	149,515