Note 6 - Fair Value (Tables)

3 Months Ended

Mar. 31, 2015

Fair Value Disclosures [Abstract]

Fair Value Measurements, Recurring and Nonrecurring [Table Text Block]

			Fair Value Measurements at Reporting Date Using
			Quoted Prices		Significant
			in Active		Other		Significant
			Markets for		Observable		Unobservable
			Identical Assets		Inputs		Inputs
	Fair Value		(Level 1)		(Level 2)		(Level 3)
March 31, 2015:
Securities available for sale:
U.S. govt. sponsored agency securities	$	299,180,255	$	-	$	299,180,255	$	-
Residential mortgage-backed and related securities		91,363,300		-		91,363,300		-
Municipal securities		29,713,314		-		29,713,314		-
Other securities		2,001,231		356,110		1,645,121		-
Derivative instruments		1,114,101		-		1,114,101		-
	$	423,372,201	$	356,110	$	423,016,091	$	-
December 31, 2014:
Securities available for sale:
U.S. govt. sponsored agency securities	$	307,869,572	$	-	$	307,869,572	$	-
Residential mortgage-backed and related securities		111,423,224		-		111,423,224		-
Municipal securities		30,399,981		-		30,399,981		-
Other securities		1,966,853		345,952		1,620,901		-
Derivative instruments		1,487,386		-		1,487,386
	$	453,147,016	$	345,952	$	452,801,064	$	-

			Fair Value Measurements at Reporting Date Using
	Fair Value		Level 1		Level 2		Level 3
March 31, 2015:
Impaired loans/leases	$	9,403,469	$	-	$	-	$	9,403,469
Other real estate owned		14,304,939		-		-		14,304,939
	$	23,708,408	$	-	$	-	$	23,708,408
December 31, 2014:
Impaired loans/leases	$	12,467,362	$	-	$	-	$	12,467,362
Other real estate owned		13,789,047		-		-		13,789,047
	$	26,256,409	$	-	$	-	$	26,256,409

Fair Value Inputs, Assets, Quantitative Information [Table Text Block]

	Quantitave Information about Level Fair Value Measurments
	Fair Value		Valuation Technique	Unobservable Input	Range
March 31, 2015:
Impaired loans/leases	$	9,403,469	Appraisal of collateral	Appraisal adjustments		-10.00% to -50.00	%
Other real estate owned		14,304,939	Appraisal of collateral	Appraisal adjustments		0.00% to -35.00	%

	Quantitave Information about Level Fair Value Measurments
	Fair Value		Valuation Technique	Unobservable Input	Range
December 31, 2014:
Impaired loans/leases	$	12,467,362	Appraisal of collateral	Appraisal adjustments		-10.00% to -50.00	%
Other real estate owned		13,789,047	Appraisal of collateral	Appraisal adjustments		0.00% to -35.00	%

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Fair Value	As of March 31, 2015				As of December 31, 2014
	Hierarchy	Carrying		Estimated		Carrying		Estimated
	Level	Value		Fair Value		Value		Fair Value
Cash and due from banks	Level 1	$	45,138,266	$	45,138,266	$	38,235,019	$	38,235,019
Federal funds sold	Level 2		14,035,000		14,035,000		46,780,000		46,780,000
Interest-bearing deposits at financial institutions	Level 2		17,118,983		17,118,983		35,334,682		35,334,682
Investment securities:
Held to maturity	Level 3		215,146,171		215,636,997		199,879,574		201,113,796
Available for sale	See Previous Table		422,258,100		422,258,100		451,659,630		451,659,630
Loans/leases receivable, net	Level 3		8,706,916		9,403,469		11,543,854		12,467,362
Loans/leases receivable, net	Level 2		1,621,861,047		1,636,808,084		1,595,384,851		1,606,646,146
Derivative instruments	Level 2		1,114,101		1,114,101		1,487,386		1,487,386
Deposits:
Nonmaturity deposits	Level 2		1,386,860,881		1,386,860,881		1,304,044,099		1,304,044,099
Time deposits	Level 2		347,408,506		348,466,000		375,623,914		376,509,000
Short-term borrowings	Level 2		183,335,719		183,335,719		268,351,670		268,351,670
Federal Home Loan Bank advances	Level 2		196,500,000		206,366,000		203,500,000		208,172,000
Other borrowings	Level 2		149,109,915		159,278,000		150,282,492		159,741,000
Junior subordinated debentures	Level 2		40,457,936		28,691,964		40,423,735		28,585,294