Note 7 - Commitments and Contingencies (Details Textual) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Number of Operating Leases Sites	9
Expiry of Standby Letters of Credit Within One Year	$ 6,400
Expiry of Standby Letter of Credit Thereafter	$ 547
Reserve for Unfunded Commitments Included in Other Liabilities		$ 695	$ 695
Real Estate Related Loans Representing Lease Portfolio	81.00%		77.00%
Insurance Claims [Member] | Maximum [Member]
Loss Contingency, Estimate of Possible Loss	$ 225
Other Liabilities [Member]
Reserve for Unfunded Commitments Included in Other Liabilities	$ 695		$ 695