Note 7 - Investment Securities (Tables)

6 Months Ended

Jun. 30, 2019

Notes Tables

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

	June 30, 2019
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	49,750	$	41	$	—	$	49,791
U.S. government agency entities		76,695		715		158		77,252
U.S. government sponsored entities		400,000		—		1,660		398,340
Mortgage-backed securities		842,315		6,336		2,546		846,105
Collateralized mortgage obligations		795		—		18		777
Corporate debt securities		98,897		465		43		99,319
Total	$	1,468,452	$	7,557	$	4,425	$	1,471,584

	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]

	Securities Available-For-Sale
	Amortized Cost		Fair Value
	(In thousands)
Due in one year or less	$	69,741	$	69,890
Due after one year through five years		479,550		478,222
Due after five years through ten years		23,551		23,637
Due after ten years		895,610		899,835
Total	$	1,468,452	$	1,471,584

Schedule of Unrealized Loss on Investments [Table Text Block]

	June 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	$	23,606	$	7	$	4,334	$	151	$	27,940	$	158
U.S. government sponsored entities		—		—		398,340		1,660		398,340		1,660
Mortgage-backed securities		2,874		7		360,270		2,539		363,144		2,546
Collateralized mortgage obligations		—		—		777		18		777		18
Corporate debt securities		33,863		43		—		—		33,863		43
Total	$	60,343	$	57	$	763,721	$	4,368	$	824,064	$	4,425

	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