Note 6 - Investment Securities (Tables)

9 Months Ended

Sep. 30, 2016

Notes Tables

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

	September 30, 2016
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	389,921	$	112	$	24	$	390,009
U.S. government sponsored entities		250,000		79		69		250,010
Mortgage-backed securities		556,454		7,186		2		563,638
Collateralized mortgage obligations		52		-		22		30
Corporate debt securities		74,962		444		937		74,469
Mutual funds		6,000		-		74		5,926
Preferred stock of government sponsored entities		2,811		565		188		3,188
Other equity securities		3,608		7,591		-		11,199
Total	$	1,283,808	$	15,977	$	1,316	$	1,298,469

	December 31, 2015
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	284,678	$	5	$	395	$	284,288
U.S. government sponsored entities		150,000		-		1,840		148,160
Mortgage-backed securities		1,073,108		560		11,399		1,062,269
Collateralized mortgage obligations		63		-		27		36
Corporate debt securities		74,955		425		1,525		73,855
Mutual funds		6,000		-		167		5,833
Preferred stock of government sponsored entities		2,811		633		228		3,216
Other equity securities		4,108		4,929		342		8,695
Total	$	1,595,723	$	6,552	$	15,923	$	1,586,352

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	$	289,859	$	289,923
Due after one year through five years		353,931		353,682
Due after five years through ten years		75,117		75,076
Due after ten years (1)		564,901		579,788
Total	$	1,283,808	$	1,298,469

Schedule of Unrealized Loss on Investments [Table Text Block]

	September 30, 2016
	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	$	149,983	$	24	$	-	$	-	$	149,983	$	24
U.S. government sponsored entities		149,931		69		-		-		149,931		69
Mortgage-backed securities		44		1		265		1		309		2
Collateralized mortgage obligations		-		-		30		22		30		22
Corporate debt securities		-		-		54,063		937		54,063		937
Mutual funds		-		-		5,926		74		5,926		74
Preferred stock of government sponsored entities		2,528		188		-		-		2,528		188
Total	$	302,486	$	282	$	60,284	$	1,034	$	362,770	$	1,316

	December 31, 2015
	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	$	224,289	$	395	$	-	$	-	$	224,289	$	395
U.S. government sponsored entities		148,160		1,840		-		-		148,160		1,840
Mortgage-backed securities		1,025,342		11,398		6		1		1,025,348		11,399
Collateralized mortgage obligations		-		-		36		27		36		27
Corporate debt securities		9,950		50		43,525		1,475		53,475		1,525
Mutual funds		-		-		5,833		167		5,833		167
Preferred stock of government sponsored entities		2,488		228		-		-		2,488		228
Other equity securities		158		342		-		-		158		342
Total	$	1,410,387	$	14,253	$	49,400	$	1,670	$	1,459,787	$	15,923