Note 3 - Loans/Leases Receivable (Details) - Composition of the Loan/Lease Portfolio - USD ($)		Mar. 31, 2016		Dec. 31, 2015		Mar. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		$ 1,865,928,672		$ 1,790,286,285
Plus deferred loan/lease orgination costs, net of fees		7,894,944		7,736,390
Gross loans/leases receivable		1,873,823,616		1,798,022,675
Less allowance for estimated losses on loans/leases		(27,395,442)		(26,140,906)		$ (23,883,273)	$ (23,074,365)
		1,846,428,174		1,771,881,769
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		682,056,782		648,159,892
Less allowance for estimated losses on loans/leases		(10,991,979)		(10,484,080)		(9,177,164)	(8,833,832)
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		766,159,365		724,368,765
Less allowance for estimated losses on loans/leases		(10,090,567)		(9,375,117)		(8,838,204)	(8,353,386)
Commercial Real Estate Portfolio Segment [Member] | Owner-occupied Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		261,730,899		252,523,164
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		37,970,546		49,083,844
Commercial Real Estate Portfolio Segment [Member] | Other Non Owner-occupied Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		466,457,920		422,761,757
Finance Leases Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	[1],[2]	172,774,048		173,655,605
Plus deferred loan/lease orgination costs, net of fees	[1]	6,493,124		6,594,582
Gross loans/leases receivable	[1]	179,267,172		180,250,187
Less allowance for estimated losses on loans/leases		(3,287,230)	[1]	(3,395,088)	[1]	(3,227,458)	(3,359,400)
	[1]	175,979,942		176,855,099
Net minimum lease payments to be received	[1]	194,005,721		195,476,230
Estimated unguaranteed residual values of leased assets	[1]	1,131,634		1,165,706
Unearned lease/residual income	[1]	(22,363,307)		(22,986,331)
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	[2],[3]	173,096,209		170,432,530
Less allowance for estimated losses on loans/leases		(1,836,622)		(1,790,150)		(1,597,754)	(1,525,952)
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	[2]	71,842,268		73,669,493
Less allowance for estimated losses on loans/leases		$ (1,189,043)		$ (1,096,471)		$ (1,042,693)	$ (1,001,795)

[1] Management performs an evaluation of the estimated unguaranteed residual values of leased assets on an annual basis, at a minimum. The evaluation consists of discussions with reputable and current vendors, which is combined with management's expertise and understanding of the current states of particular industries to determine informal valuations of the equipment. As necessary and where available, management will utilize valuations by independent appraisers. The large majority of leases with residual values contain a lease options rider, which requires the lessee to pay the residual value directly, finance the payment of the residual value, or extend the lease term to pay the residual value. In these cases, the residual value is protected and the risk of loss is minimal. There were no losses related to residualvalues for the three months ended March 31, 2016 and 2015.

[2] Performing = loans/leases accruing and less than 90 days past due. Nonperforming = loans/leases on nonaccrual, accruing loans/leases that are greater than or equal to 90 days past due, and accruing TDRs.

[3] Includes residential real estate loans held for sale totaling $765,385 and $565,850 as of March 31, 2016, and December 31, 2015, respectively.