Note 4 - Loans Leases Receivable - Leases By Delinquency Status (Details) - USD ($)		Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Loans		$ 2,956,713,493		$ 2,397,414,282
Nonperforming Financial Instruments [Member]
Loans			$ 18,642,377	21,232,408
Finance Leases Portfolio Segment [Member]
Loans	[1]	141,448,232		165,419,360
Finance Leases Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans		137,778,740		161,749,710
Finance Leases Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans		3,669,492	3,669,492	3,669,650
Residential Portfolio Segment [Member]
Loans	[2]	258,646,265		229,233,104
Residential Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans		256,935,448		227,277,070
Residential Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans		1,710,818	1,710,818	1,956,034
Consumer Portfolio Segment [Member]
Loans		118,610,799		81,665,695
Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans		118,333,529		81,449,104
Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans		277,270	$ 277,270	216,591
Lease Residential and Consumer Portfolio Segments [Member]
Loans		$ 518,705,296		$ 476,318,159
As a % of Total		100.00%		100.00%
Lease Residential and Consumer Portfolio Segments [Member] | Performing Financial Instruments [Member]
Loans		$ 513,047,716		$ 470,475,884
As a % of Total		98.91%		98.77%
Lease Residential and Consumer Portfolio Segments [Member] | Nonperforming Financial Instruments [Member]
Loans		$ 5,657,580		$ 5,842,275
As a % of Total		1.09%		1.23%

[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 and nine months ended September 30, 2017 and 2016.

[2] Includes residential real estate loans held for sale totaling $645,001 and $1,135,500 as of December 31, 2017 and 2016, respectively.