Note 7 - Investment Securities (Tables)

9 Months Ended

Sep. 30, 2019

Notes Tables

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

	September 30, 2019
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. government agency entities	$	92,477	$	750	$	273	$	92,954
U.S. government sponsored entities		350,000		—		2,301		347,699
Mortgage-backed securities		880,406		7,714		1,385		886,735
Collateralized mortgage obligations		683		—		18		665
Corporate debt securities		98,865		533		13		99,385
Total	$	1,422,431	$	8,997	$	3,990	$	1,427,438

	December 31, 2018
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	124,801	$	—	$	50	$	124,751
U.S. government agency entities		6,066		—		195		5,871
U.S. government sponsored entities		400,000		—		11,638		388,362
Mortgage-backed securities		670,874		960		15,089		656,745
Collateralized mortgage obligations		1,005		—		28		977
Corporate debt securities		64,985		818		—		65,803
Total	$	1,267,731	$	1,778	$	27,000	$	1,242,509

Investments Classified by Contractual Maturity Date [Table Text Block]

	September 30, 2019
	Securities Available-For-Sale
	Amortized Cost		Fair Value
	(In thousands)
Due in one year or less	$	19,993	$	20,103
Due after one year through five years		429,449		427,578
Due after five years through ten years		41,718		41,710
Due after ten years		931,271		938,047
Total	$	1,422,431	$	1,427,438

Schedule of Unrealized Loss on Investments [Table Text Block]

	September 30, 2019
	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	$	49,796	$	108	$	3,748	$	165	$	53,544	$	273
U.S. government sponsored entities		—		—		347,699		2,301		347,699		2,301
Mortgage-backed securities		115,727		220		146,666		1,165		262,393		1,385
Collateralized mortgage obligations		—		—		665		18		665		18
Corporate debt securities		28,819		13		—		—		28,819		13
Total	$	194,342	$	341	$	498,778	$	3,649	$	693,120	$	3,990

	December 31, 2018
	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	$	124,751	$	50	$	—	$	—	$	124,751	$	50
U.S. government agency entities		3,388		77		2,483		118		5,871		195
U.S. government sponsored entities		—		—		388,362		11,638		388,362		11,638
Mortgage-backed securities		48,528		502		507,701		14,587		556,229		15,089
Collateralized mortgage obligations		—		—		977		28		977		28
Total	$	176,667	$	629	$	899,523	$	26,371	$	1,076,190	$	27,000