Note 3 - Investment Securities (Tables)

9 Months Ended

Sep. 30, 2013

Investment Holdings [Abstract]

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

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
September 30, 2013:
Securities held to maturity:
Municipal securities	$	130,311,845	$	456,156	$	(6,520,899	)	$	124,247,102
Other securities		1,050,000		-		(4,740	)		1,045,260
	$	131,361,845	$	456,156	$	(6,525,639	)	$	125,292,362
Securities available for sale:
U.S. govt. sponsored agency securities	$	383,193,241	$	75,797	$	(15,744,151	)	$	367,524,887
Residential mortgage-backed and related securities		167,759,290		1,318,307		(2,533,127	)		166,544,470
Municipal securities		36,242,570		978,391		(761,791	)		36,459,170
Other securities		1,358,524		450,278		-			1,808,802
	$	588,553,625	$	2,822,773	$	(19,039,069	)	$	572,337,329
December 31, 2012:
Securities held to maturity:
Municipal securities	$	71,429,385	$	997,969	$	(71,648	)	$	72,355,706
Other securities		650,000		-		-			650,000
	$	72,079,385	$	997,969	$	(71,648	)	$	73,005,706
Securities available for sale:
U.S. govt. sponsored agency securities	$	336,570,995	$	2,198,655	$	(160,279	)	$	338,609,371
Residential mortgage-backed and related securities		160,035,196		3,736,821		(170,914	)		163,601,103
Municipal securities		24,508,015		1,696,555		(18,834	)		26,185,736
Trust preferred securities		86,200		53,200		-			139,400
Other securities		1,347,113		300,732		(23,469	)		1,624,376
	$	522,547,519	$	7,985,963	$	(373,496	)	$	530,159,986

Schedule of Unrealized Loss on Investments [Table Text Block]

	Less than 12 Months					12 Months or More					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
September 30, 2013:
Securities held to maturity:
Municipal securities	$	92,786,083	$	(6,520,899	)	$	-	$	-		$	92,786,083	$	(6,520,899	)
Other securities		495,260		(4,740	)		-		-			495,260		(4,740	)
	$	93,281,343	$	(6,525,639	)	$	-	$	-		$	93,281,343	$	(6,525,639	)
Securities available for sale:
U.S. govt. sponsored agency securities	$	351,006,164	$	(15,744,151	)	$	-	$	-		$	351,006,164	$	(15,744,151	)
Residential mortgage-backed and related securities		106,889,560		(2,517,649	)		1,279,117		(15,478	)		108,168,677		(2,533,127	)
Municipal securities		16,263,130		(761,791	)		-		-			16,263,130		(761,791	)
	$	474,158,854	$	(19,023,591	)	$	1,279,117	$	(15,478	)	$	475,437,971	$	(19,039,069	)
December 31, 2012:
Securities held to maturity:
Municipal securities	$	4,282,352	$	(71,648	)	$	-	$	-		$	4,282,352	$	(71,648	)
Securities available for sale:
U.S. govt. sponsored agency securities	$	55,621,718	$	(160,279	)	$	-	$	-		$	55,621,718	$	(160,279	)
Residential mortgage-backed and related securities		29,324,928		(170,914	)		-		-			29,324,928		(170,914	)
Municipal securities		1,039,625		(18,834	)		-		-			1,039,625		(18,834	)
Other securities		-		-			217,500		(23,469	)		217,500		(23,469	)
	$	85,986,271	$	(350,027	)	$	217,500	$	(23,469	)	$	86,203,771	$	(373,496	)

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

	Three Months Ended					Nine Months Ended
	September 30, 2013			September 30, 2012		September 30, 2013			September 30, 2012
Proceeds from sales of securities	$	31,225,516		$	-	$	37,393,047		$	19,215,075
Pre-tax gross gains from sales of securities		506,611			-		523,071			104,600
Pre-tax gross losses from sales of securities		(89,675	)		-		(89,675	)		-

Investments Classified by Contractual Maturity Date [Table Text Block]

	Amortized Cost		Fair Value
Securities held to maturity:
Due in one year or less	$	2,066,615	$	2,066,245
Due after one year through five years		9,982,269		9,827,587
Due after one year through five years		119,312,961		113,398,530
	$	131,361,845	$	125,292,362
Securities available for sale:
Due in one year or less	$	5,220,265	$	5,231,685
Due after one year through five years		42,271,445		42,124,141
Due after five years		371,944,101		356,628,231
	$	419,435,811	$	403,984,057
Residential mortgage-backed and related securities		167,759,290		166,544,470
Other securities		1,358,524		1,808,802
	$	588,553,625	$	572,337,329

	Amortized Cost		Fair Value
Securities held to maturity:
Municipal securities	$	94,833,231	$	89,637,985
Securities available for sale:
U.S. govt. sponsored agency securities		349,624,386		334,694,737
Municipal securities		23,163,866		22,996,424
	$	372,788,252	$	357,691,161