Note 3 - Loans/Leases Receivable (Details) - Composition of the Loan/Lease Portfolio - USD ($)		Sep. 30, 2015		Jun. 30, 2015	Dec. 31, 2014		Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		$ 1,748,195,577			$ 1,623,338,950
Plus deferred loan/lease orgination costs, net of fees		7,476,792			6,664,120
Gross loans/leases receivable		1,755,672,369			1,630,003,070
Less allowance for estimated losses on loans/leases		(25,534,344)		$ (26,146,000)	(23,074,365)		$ (22,767,917)	$ (23,067,024)	$ (21,448,048)
Net loans/leases receivable		1,730,138,025			1,606,928,705
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		647,398,566			523,927,140
Less allowance for estimated losses on loans/leases		(10,532,168)		(10,020,866)	(8,750,317)		(6,914,058)	(6,549,378)	(5,648,774)
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		692,569,134			702,140,422
Less allowance for estimated losses on loans/leases		(8,708,715)		(9,929,656)	(8,353,386)		(10,028,668)	(10,277,692)	(10,705,434)
Commercial Real Estate Portfolio Segment [Member] | Owner-occupied Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		247,779,183			260,069,080
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases		45,011,361			68,118,989
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		399,778,590			373,952,353
Finance Leases Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	[1],[2]	173,304,223			166,032,416
Plus deferred loan/lease orgination costs, net of fees	[1]	6,710,311			6,639,244
Gross loans/leases receivable	[1]	180,014,534			172,671,660
Less allowance for estimated losses on loans/leases		(3,248,633)	[1]	(3,352,303)	(3,442,915)	[1]	(3,106,887)	(3,319,131)	(2,517,217)
Net loans/leases receivable	[1]	176,765,901			169,228,745
Net minimum lease payments to be received	[1]	195,626,557			188,181,432
Estimated unguaranteed residual values of leased assets	[1]	1,165,706			1,488,342
Unearned lease/residual income	[1]	(23,488,040)			(23,637,358)
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	[2],[3]	165,060,663			158,632,492
Less allowance for estimated losses on loans/leases		(1,829,056)		(1,720,135)	(1,525,952)		(1,353,070)	(1,439,185)	(1,395,849)
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	[2]	69,862,991			72,606,480
Less allowance for estimated losses on loans/leases		$ (1,215,772)		$ (1,123,040)	$ (1,001,795)		$ (1,365,234)	$ (1,481,638)	$ (1,180,774)

[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 residual values for the three or nine months ended September 30, 2015 and 2014.

[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 $533,225 and $553,000 as of September 30, 2015, and December 31, 2014, respectively.