Note 3 - Loans Leases Receivable - Leases By Delinquency Status (Details) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Loans and Leases Receivable, Net of Deferred Income	$ 3,105,901,458	$ 2,956,713,493
Nonperforming Financial Instruments [Member]
Loans and Leases Receivable, Net of Deferred Income	13,900,381	18,642,377
Commercial Lease Residential And Consumer Portfolio Segments [Member] | Delinquency Status [Member]
Loans and Leases Receivable, Net of Deferred Income	576,398,192	585,463,693
Commercial Lease Residential And Consumer Portfolio Segments [Member] | Performing Less Than Ninety Days Past Due [Member}
Loans and Leases Receivable, Net of Deferred Income	571,457,740	578,894,893
Commercial Lease Residential And Consumer Portfolio Segments [Member] | Non Performing Greater Than Ninety Days Past Due [Member]
Loans and Leases Receivable, Net of Deferred Income	4,940,452	6,568,800
Commercial Portfolio Segment [Member]
Loans and Leases Receivable, Net of Deferred Income	1,273,000,094	1,134,516,315
Commercial Portfolio Segment [Member] | Delinquency Status [Member]
Loans and Leases Receivable, Net of Deferred Income	92,815,742	66,758,397
Commercial Portfolio Segment [Member] | Performing Less Than Ninety Days Past Due [Member}
Loans and Leases Receivable, Net of Deferred Income	92,361,366	65,847,177
Commercial Portfolio Segment [Member] | Non Performing Greater Than Ninety Days Past Due [Member]
Loans and Leases Receivable, Net of Deferred Income	454,376	911,220
Commercial Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans and Leases Receivable, Net of Deferred Income	2,285,471	6,455,535
Finance Leases Portfolio Segment [Member]
Loans and Leases Receivable, Net of Deferred Income	133,196,613	141,448,232
Finance Leases Portfolio Segment [Member] | Delinquency Status [Member]
Loans and Leases Receivable, Net of Deferred Income	133,196,613	141,448,232
Finance Leases Portfolio Segment [Member] | Performing Less Than Ninety Days Past Due [Member}
Loans and Leases Receivable, Net of Deferred Income	130,530,177	137,778,740
Finance Leases Portfolio Segment [Member] | Non Performing Greater Than Ninety Days Past Due [Member]
Loans and Leases Receivable, Net of Deferred Income	2,666,436	3,669,492
Finance Leases Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans and Leases Receivable, Net of Deferred Income	2,666,436	3,669,492
Residential Portfolio Segment [Member]
Loans and Leases Receivable, Net of Deferred Income	257,433,713	258,646,265
Residential Portfolio Segment [Member] | Delinquency Status [Member]
Loans and Leases Receivable, Net of Deferred Income	257,433,713	258,646,265
Residential Portfolio Segment [Member] | Performing Less Than Ninety Days Past Due [Member}
Loans and Leases Receivable, Net of Deferred Income	255,847,659	256,935,447
Residential Portfolio Segment [Member] | Non Performing Greater Than Ninety Days Past Due [Member]
Loans and Leases Receivable, Net of Deferred Income	1,586,054	1,710,818
Residential Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans and Leases Receivable, Net of Deferred Income	1,586,054	1,710,818
Consumer Portfolio Segment [Member]
Loans and Leases Receivable, Net of Deferred Income	92,952,124	118,610,799
Consumer Portfolio Segment [Member] | Delinquency Status [Member]
Loans and Leases Receivable, Net of Deferred Income	92,952,124	118,610,799
Consumer Portfolio Segment [Member] | Performing Less Than Ninety Days Past Due [Member}
Loans and Leases Receivable, Net of Deferred Income	92,718,538	118,333,529
Consumer Portfolio Segment [Member] | Non Performing Greater Than Ninety Days Past Due [Member]
Loans and Leases Receivable, Net of Deferred Income	233,586	277,270
Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans and Leases Receivable, Net of Deferred Income	$ 233,586	$ 277,270
Commercial and Commercial Real Estate Portfolio Segments [Member] | Delinquency Status [Member]
Financing Receivables Portfolio Percentage	100.00%	100.00%
Commercial and Commercial Real Estate Portfolio Segments [Member] | Performing Less Than Ninety Days Past Due [Member}
Financing Receivables Portfolio Percentage	99.14%	98.88%
Commercial and Commercial Real Estate Portfolio Segments [Member] | Non Performing Greater Than Ninety Days Past Due [Member]
Financing Receivables Portfolio Percentage	0.86%	1.12%