Note 10 - Commitments and Contingencies - Financial Instruments Outstanding Whose Contract Amount Represents Credit Risk (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Letters of Credit	$ 1,435	$ 1,536
Loan Origination Commitments [Member]
Loan Commitments	$ 100,518	$ 96,374

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

No definition available.

Name:	us-gaap_ContractualObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant