Note 7 - Investment Securities (Tables)

6 Months Ended

Jun. 30, 2018

Notes Tables

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

	June 30, 2018
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Debt Securities Available-for-Sale
U.S. treasury securities	$	348,677	$	8	$	141	$	348,544
U.S. government agency entities		8,397		-		208		8,189
U.S. government sponsored entities		400,000		-		16,041		383,959
Mortgage-backed securities		676,855		189		18,756		658,288
Collateralized mortgage obligations		1,233		-		30		1,203
Corporate debt securities		74,980		786		-		75,766
Total	$	1,510,142	$	983	$	35,176	$	1,475,949

	December 31, 2017
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	249,877	$	-	$	357	$	249,520
U.S. government agency entities		9,047		11		70		8,988
U.S. government sponsored entities		400,000		-		9,664		390,336
State and municipal securities		1,944		-		30		1,914
Mortgage-backed securities		577,987		241		6,259		571,969
Collateralized mortgage obligations		1,533		-		17		1,516
Corporate debt securities		80,007		1,291		17		81,281
Mutual funds		6,500		-		270		6,230
Preferred stock of government sponsored entities		5,842		4,260		-		10,102
Other equity securities		3,608		8,162		-		11,770
Total	$	1,336,345	$	13,965	$	16,684	$	1,333,626

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	$	358,743	$	358,622
Due after one year through five years		465,994		450,736
Due after five years through ten years		4,478		4,314
Due after ten years		680,927		662,277
Total	$	1,510,142	$	1,475,949

Schedule of Unrealized Loss on Investments [Table Text Block]

	June 30, 2018
	Temporarily impaired securities
	Less than 12 months				12 months or longer				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
	(In thousands)
Debt Securities Available-for-Sale
U.S. treasury securities	$	124,463	$	49	$	49,906	$	92	$	174,369	$	141
U.S. government agency entities		8,189		208		-		-		8,189		208
U.S. government sponsored entities		-		-		383,959		16,041		383,959		16,041
Mortgage-backed securities		465,499		12,349		160,485		6,407		625,984		18,756
Collateralized mortgage obligations		1,203		30		-		-		1,203		30
Total debt securities	$	599,354	$	12,636	$	594,350	$	22,540	$	1,193,704	$	35,176
Equity Securities
Preferred stock of government sponsored entities		7,480		2,623		-		-		7,480		2,623
Mutual funds		-		-		6,082		148		6,082		148
Other equity securities		9,569		2,200		-		-		9,569		2,200
Total equity securities	$	17,049	$	4,823	$	6,082	$	148	$	23,131	$	4,971

	December 31, 2017
	Temporarily impaired securities
	Less than 12 months				12 months or longer				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	199,823	$	62	$	49,697	$	295	$	249,520	$	357
U.S. government agency entities		5,711		70		-		-		5,711		70
U.S. government sponsored entities		-		-		390,336		9,664		390,336		9,664
State and municipal securities		1,914		30		-		-		1,914		30
Mortgage-backed securities		342,436		3,147		178,617		3,112		521,053		6,259
Collateralized mortgage obligations		1,516		17		-		-		1,516		17
Corporate debt securities		5,015		17		-		-		5,015		17
Mutual funds		-		-		6,230		270		6,230		270
Total	$	556,415	$	3,343	$	624,880	$	13,341	$	1,181,295	$	16,684