Note 4 - Loans Leases Receivable (Details Textual)	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)		Dec. 31, 2015 USD ($)
Number of Leases	10
Leveraged Lease Investment	$ 929,932
Losses on Residual Value	0	$ 0		$ 0
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage	645,001	1,135,500
Financing Receivable, Recorded Investment, Nonaccrual Status	11,441,234	13,919,066
Financing Receivable, Modifications, Recorded Investment	$ 9,394,967	$ 8,647,007
Financing Receivable, Modifications, Number of Contracts	35	29
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 2,752,344	$ 7,880,881
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	6	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 251,940
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	65,623	$ 341,952
Threshold for Related Party Loans Evaluated	$ 60,000	$ 60,000		$ 60,000
Nonaccrual [Member]
Financing Receivable, Modifications, Number of Contracts	7	8
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 279,245	$ 2,008,424
Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	2,282,495	2,300,479
Residential Portfolio Segment [Member]
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage	645,001	1,135,500
Financing Receivable, Recorded Investment, Nonaccrual Status	1,363,806	1,075,639	[1]
Residential Portfolio Segment [Member] | Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	115,190	43,579
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	1,231,353	4,187,786	[1]
Commercial Portfolio Segment [Member] | Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	122,598	48,501
Commercial Real Estate Portfolio Segment [Member] | Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	1,336,871	1,380,047
Finance Leases Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	2,175,044	2,446,181	[1]
Finance Leases Portfolio Segment [Member] | Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	700,255	816,149
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	249,091	87,344	[1]
Consumer Portfolio Segment [Member] | Troubled Debt Restructurings [Member]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 7,581	$ 12,203
No Lease End Option Rider [Member]
Number of Leases		13
Leveraged Lease Investment		$ 1,085,164

[1] At December 31, 2016, nonaccrual loans/leases included $2,300,479 of TDRs, including $48,501 in C&I loans, $1,380,047 in CRE loans, $816,149 in direct financing leases, $43,579 in residential real estate loans, and $12,203 in installment loans.