Note 3 - Investment Securities (Tables)

9 Months Ended

Sep. 30, 2014

Investments, Debt and Equity Securities [Abstract]

Investment [Table Text Block]

	September 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	$	455,827	$	961	$	(5,403	)	$	451,385	$	395,198	$	50	$	(10,535	)	$	384,713
Mortgage-backed securities		30,954		9		(602	)		30,361		34,425		17		(442	)		34,000
State and political subdivisions		335,329		8,762		(872	)		341,080		315,445		2,165		(5,498	)		312,112
Other securities		620		-		-			620		620		-		-			620
Total HTM	$	822,730	$	9,732	$	(6,877	)	$	823,446	$	745,688	$	2,232	$	(16,475	)	$	731,445
Available-for-Sale
U.S. Treasury	$	4,000	$	-	$	(10	)	$	3,991	$	4,001	$	-	$	(16	)	$	3,985
U.S. Government agencies		283,620		17		(3,316	)		280,321		183,781		8		(5,572	)		178,217
Mortgage-backed securities		52		1		(21	)		32		1,735		156		-			1,891
State and political subdivisions		8,892		12		(2	)		8,903		7,860		4		(3	)		7,861
Other securities		23,839		395		(9	)		24,226		19,840		484		(1	)		20,323
Total AFS	$	320,405	$	425	$	(3,358	)	$	317,473	$	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	$	316,956	$	(4,059	)	$	72,610	$	(1,343	)	$	389,566	$	(5,403	)
Mortgage-backed securities		27,239		(602	)		-		-			27,239		(602	)
State and political subdivisions		42,626		(425	)		24,636		(447	)		67,263		(872	)
Total HTM	$	386,821	$	(5,086	)	$	97,246	$	(1,790	)	$	484,068	$	(6,877	)
Available-for-Sale
U.S. Treasury	$	3,991	$	(10	)	$	-	$	-		$	3,991	$	(10	)
U.S. Government agencies		211,696		(2,092	)		59,080		(1,224	)		270,776		(3,316	)
Mortgage-backed securities		1,570		(21	)		-		-			1,570		(21	)
State and political subdivisions		699		(2	)		-		-			699		(2	)
Other securities		1,681		(9	)		-		-			1,681		(9	)
Total AFS	$	219,637	$	(2,134	)	$	59,080	$	(1,224	)	$	278,717	$	(3,358	)

Investment Income [Table Text Block]

	Three Months Ended September 30,				Nine Months Ended September 30,
(In thousands)	2014		2013		2014		2013
Taxable:
Held-to-maturity	$	1,440	$	818	$	4,167	$	2,281
Available-for-sale		603		540		1,882		1,605
Non-taxable:
Held-to-maturity		2,647		2,066		7,900		5,450
Available-for-sale		27		4		83		13
Total	$	4,717	$	3,428	$	14,032	$	9,349

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	$	19,171	$	19,201	$	4,972	$	4,981
After one through five years		378,700		376,377		179,804		179,154
After five through ten years		214,805		213,800		25,236		24,813
After ten years		210,054		214,068		87,891		85,630
Other securities		-		-		22,502		22,895
Total	$	822,730	$	823,446	$	320,405	$	317,473