Note 7 - Commitments and Contingencies (Details Textual)	3 Months Ended
	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Number of Operating Leases Sites	9
Expiry of Standby Letters of Credit Within One Year	$ 6,300,000
Expiry of Standby Letter of Credit Thereafter	375,000
Reserve for Unfunded Commitments Included in Other Liabilities	$ 695,000	$ 695,000
Real Estate Related Loans Representing Lease Portfolio	80.00%	77.00%
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