Note 15 - Commitments and Contingencies (Details Textual)	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Number of Operating Leases Sites	9
Expiry of Standby Letters of Credit Within One Year	$ 1,300,000
Expiry of Standby Letter of Credit Thereafter	5,400,000
Reserve for Unfunded Commitments Included in Other Liabilities	$ 695,000	$ 695,000
Real Estate Related Loans Representing Lease Portfolio	77.00%	75.00%
Insurance Claims [Member] | Maximum [Member]
Loss Contingency, Estimate of Possible Loss	$ 225,000
Other Liabilities [Member]
Reserve for Unfunded Commitments Included in Other Liabilities	$ 695,000	$ 695,000