Note 3 - Investment Securities (Tables)

9 Months Ended

Sep. 30, 2015

Investments, Debt and Equity Securities [Abstract]

Investment [Table Text Block]

	September 30, 2015
			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		Losses			Value
Held-to-Maturity Securities:	(in thousands)
State and municipals	$	16,991	$	617	$	-		$	17,608
Pass-through mortgage securities		766		96		-			862
Collateralized mortgage obligations		931		69		-			1,000
	$	18,688	$	782	$	-		$	19,470
Available-for-Sale Securities:
State and municipals	$	410,887	$	17,005	$	(399	)	$	427,493
Pass-through mortgage securities		155,616		1,182		(572	)		156,226
Collateralized mortgage obligations		164,587		4,017		(287	)		168,317
	$	731,090	$	22,204	$	(1,258	)	$	752,036
	December 31, 2014
Held-to-Maturity Securities:
State and municipals	$	19,836	$	843	$	-		$	20,679
Pass-through mortgage securities		856		110		-			966
Collateralized mortgage obligations		1,141		84		-			1,225
	$	21,833	$	1,037	$	-		$	22,870
Available-for-Sale Securities:
State and municipals	$	393,637	$	18,612	$	(452	)	$	411,797
Pass-through mortgage securities		130,966		1,421		(1,206	)		131,181
Collateralized mortgage obligations		226,879		4,847		(559	)		231,167
	$	751,482	$	24,880	$	(2,217	)	$	774,145

Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block]

	September 30, 2015
	Less than					12 Months
	12 Months					or More					Total
	Fair		Unrealized			Fair		Unrealized			Fair		Unrealized
	Value		Loss			Value		Loss			Value		Loss
	(in thousands)
State and municipals	$	31,378	$	(308	)	$	5,269	$	(91	)	$	36,647	$	(399	)
Pass-through mortgage securities		60,790		(232	)		28,997		(340	)		89,787		(572	)
Collateralized mortgage obligations		18,274		(16	)		12,127		(271	)		30,401		(287	)
Total temporarily impaired	$	110,442	$	(556	)	$	46,393	$	(702	)	$	156,835	$	(1,258	)
	December 31, 2014
State and municipals	$	19,386	$	(145	)	$	21,198	$	(307	)	$	40,584	$	(452	)
Pass-through mortgage securities		-		-			100,556		(1,206	)		100,556		(1,206	)
Collateralized mortgage obligations		15,420		(84	)		17,227		(475	)		32,647		(559	)
Total temporarily impaired	$	34,806	$	(229	)	$	138,981	$	(1,988	)	$	173,787	$	(2,217	)

Realized Gain (Loss) on Investments [Table Text Block]

	Nine Months Ended						Three Months Ended
	September 30,						September 30,
	2015			2014			2015		2014
	(in thousands)
Proceeds	$	66,140		$	3,390		$	-	$	70
Gains	$	1,501		$	42		$	-	$	1
Losses		(376	)		(20	)		-		-
Net gain	$	1,125		$	22		$	-	$	1

Investments Classified by Contractual Maturity Date [Table Text Block]

	Amortized Cost		Fair Value
Held-to-Maturity Securities:	(in thousands)
Within one year	$	3,951	$	3,971
After 1 through 5 years		8,875		9,275
After 5 through 10 years		3,332		3,491
After 10 years		833		871
Mortgage-backed securities		1,697		1,862
	$	18,688	$	19,470
Available-for-Sale Securities:
Within one year	$	9,117	$	9,324
After 1 through 5 years		37,545		38,935
After 5 through 10 years		143,566		148,642
After 10 years		220,659		230,592
Mortgage-backed securities		320,203		324,543
	$	731,090	$	752,036