Note 7 - Investment Securities (Tables)

9 Months Ended

Sep. 30, 2017

Notes Tables

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

	September 30, 2017
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	399,741	$	-	$	305	$	399,436
U.S. government agency entities		9,679		27		6		9,700
U.S. government sponsored entities		400,000		-		6,278		393,722
State and municipal securities		1,943		-		12		1,931
Mortgage-backed securities		447,959		468		2,362		446,065
Collateralized mortgage obligations		1,715		-		5		1,710
Corporate debt securities		80,007		904		5		80,906
Mutual funds		6,500		-		229		6,271
Preferred stock of government sponsored entities		4,117		3,970		-		8,087
Other equity securities		13,294		7,463		98		20,659
Total	$	1,364,955	$	12,832	$	9,300	$	1,368,487

	December 31, 2016
			Gross		Gross
	Amortized		Unrealized		Unrealized
	Cost		Gains		Losses		Fair Value
	(In thousands)
Securities Available-for-Sale
U.S. treasury securities	$	489,839	$	35	$	857	$	489,017
U.S. government sponsored entities		400,000		-		9,669		390,331
Mortgage-backed securities		339,241		309		3,290		336,260
Collateralized mortgage obligations		48		-		20		28
Corporate debt securities		74,965		247		862		74,350
Mutual funds		6,500		-		270		6,230
Preferred stock of government sponsored entities		2,811		4,497		-		7,308
Other equity securities		3,608		7,213		-		10,821
Total	$	1,317,012	$	12,301	$	14,968	$	1,314,345

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	$	415,782	$	415,555
Due after one year through five years		465,328		459,924
Due after five years through ten years		8,658		8,647
Due after ten years (1)		475,187		484,361
Total	$	1,364,955	$	1,368,487

Schedule of Unrealized Loss on Investments [Table Text Block]

	September 30, 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	$	339,707	$	46	$	49,729	$	259	$	389,436	$	305
U.S. government sponsored entities		395,774		6,284		-		-		395,774		6,284
State and municipal securities		1,931		12		-		-		1,931		12
Mortgage-backed securities		359,112		2,359		122		3		359,234		2,362
Collateralized mortgage obligations		1,710		5		-		-		1,710		5
Corporate debt securities		5,029		5		-		-		5,029		5
Mutual funds		-		-		6,271		229		6,271		229
Other equity securities		4,680		98		-		-		4,680		98
Total	$	1,107,943	$	8,809	$	56,122	$	491	$	1,164,065	$	9,300

	December 31, 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	$	299,088	$	857	$	-	$	-	$	299,088	$	857
U.S. government sponsored entities		390,331		9,669		-		-		390,331		9,669
Mortgage-backed securities		328,236		3,288		62		2		328,298		3,290
Collateralized mortgage obligations		-		-		28		20		28		20
Corporate debt securities		-		-		29,138		862		29,138		862
Mutual funds		-		-		6,230		270		6,230		270
Total	$	1,017,655	$	13,814	$	35,458	$	1,154	$	1,053,113	$	14,968