Note 3 - Investment Securities (Tables)

6 Months Ended

Jun. 30, 2014

Investments, Debt and Equity Securities [Abstract]

Investment [Table Text Block]

	June 30,2014										December 31,2013
(In thousands)	Amortized Cost		Gross Unrealized Gains			Gross Unrealized (Losses)			Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Estimated Fair Value
Held-to-Maturity
U.S. Government agencies	$	449,201	$	1,028		$	(5,051	)	$	445,178	$	395,198	$	50	$	(10,535	)	$	384,713
Mortgage-backed securities		32,204		176			(519	)		31,861		34,425		17		(442	)		34,000
State and political subdivisions		317,938		6,137			(1,333	)		322,742		315,445		2,165		(5,498	)		312,112
Other securities		620		--			--			620		620		--		--			620
Total HTM	$	799,963	$	7,341		$	(6,903	)	$	800,401	$	745,688	$	2,232	$	(16,475	)	$	731,445
Available-for-Sale
U.S. Treasury	$	4,001	$	--		$	(7	)	$	3,994	$	4,001	$	--	$	(16	)	$	3,985
U.S. Government agencies		241,545		(254	)		(2,880	)		238,411		183,781		8		(5,572	)		178,217
Mortgage-backed securities		1,636		322			--			1,958		1,735		156		--			1,891
State and political subdivisions		6,910		13			(3	)		6,920		7,860		4		(3	)		7,861
Other securities		18,456		597			--			19,053		19,840		484		(1	)		20,323
Total AFS	$	272,548	$	678		$	(2,890	)	$	270,336	$	217,217	$	652	$	(5,592	)	$	212,277

Schedule of Unrealized Loss on Investments [Table Text Block]

	Less Than 12 Months					12 Months or More					Total
(In thousands)	Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses
Held-to-Maturity
U.S. Government agencies	$	228,195	$	(2,194	)	$	142,085	$	(2,857	)	$	370,280	$	(5,051	)
Mortgage-backed securities		26,586		(519	)		--		--			26,586		(519	)
State and political subdivisions		22,563		(334	)		34,513		(999	)		57,076		(1,333	)
Total HTM	$	277,344	$	(3,047	)	$	176,598	$	(3,856	)	$	453,942	$	(6,903	)
Available-for-Sale
U.S. Treasury	$	3,994	$	(7	)	$	--	$	--		$	3,994	$	(7	)
U.S. Government agencies		134,656		(983	)	$	93,901		(1,897	)		228,557		(2,880	)
State and political subdivisions		699		(3	)		--		--			699		(3	)
Total AFS	$	139,349	$	(993	)	$	93,901	$	(1,897	)	$	233,250	$	(2,890	)

Investment Income [Table Text Block]

	Three Months Ended June 30,				Six Months Ended June 30,
(In thousands)	2014		2013		2014		2013
Taxable:
Held-to-maturity	$	1,378	$	760	$	2,727	$	1,463
Available-for-sale		729		546		1,279		1,065
Non-taxable:
Held-to-maturity		2,633		1,709		5,252		3,384
Available-for-sale		26		4		57		9
Total	$	4,766	$	3,019	$	9,315	$	5,921

Investments Classified by Contractual Maturity Date [Table Text Block]

	Held-to-Maturity				Available-for-Sale
(In thousands)	Amortized Cost		Fair Value		Amortized Cost		Fair Value
One year or less	$	23,361	$	23,427	$	2,257	$	2,261
After one through five years		341,201		339,224		161,497		160,697
After five through ten years		239,939		239,203		90,093		88,119
After ten years		195,462		198,547		808		882
Other securities		--		--		17,893		18,377
Total	$	799,963	$	800,401	$	272,548	$	270,336