Note 8 - Investment Securities (Tables)

9 Months Ended

Sep. 30, 2022

Notes Tables

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

	September 30, 2022
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	242,510	$	—	$	1,110	$	241,400
U.S. government agency entities		68,712		526		126		69,112
Mortgage-backed securities		1,001,832		58		140,402		861,488
Collateralized mortgage obligations		35,378		—		3,669		31,709
Corporate debt securities		228,879		—		18,177		210,702
Total	$	1,577,311	$	584	$	163,484	$	1,414,411

	December 31, 2021
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. government agency entities	$	86,475	$	1,169	$	135	$	87,509
Mortgage-backed securities		886,614		9,465		7,414		888,665
Collateralized mortgage obligations		9,547		—		430		9,117
Corporate debt securities		144,231		441		2,654		142,018
Total	$	1,126,867	$	11,075	$	10,633	$	1,127,309

Investments Classified by Contractual Maturity Date [Table Text Block]

	September 30, 2022
	Securities Available-For-Sale
	Amortized Cost		Fair Value
	(In thousands)
Due in one year or less	$	282,514	$	280,897
Due after one year through five years		176,541		159,389
Due after five years through ten years		147,198		138,428
Due after ten years		971,058		835,697
Total	$	1,577,311	$	1,414,411

Schedule of Unrealized Loss on Investments [Table Text Block]

	September 30, 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	$	241,400	$	1,110	$	—	$	—	$	241,400	$	1,110
U.S. government agency entities		—		—		2,155		126		2,155		126
Mortgage-backed securities		551,053		69,037		309,737		71,365		860,790		140,402
Collateralized mortgage obligations		24,901		1,794		6,809		1,875		31,710		3,669
Corporate debt securities		118,913		4,364		91,790		13,813		210,703		18,177
Total	$	936,267	$	76,305	$	410,491	$	87,179	$	1,346,758	$	163,484

	December 31, 2021
	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. government agency entities	$	—	$	—	$	2,337	$	135	$	2,337	$	135
Mortgage-backed securities		527,276		6,659		6,496		755		533,772		7,414
Collateralized mortgage obligations		8,989		417		128		13		9,117		430
Corporate debt securities		103,720		2,122		19,468		532		123,188		2,654
Total	$	639,985	$	9,198	$	28,429	$	1,435	$	668,414	$	10,633