Note 15 - Commitments and Contingencies - Financial Instruments Outstanding Whose Contract Amount Represents Credit Risk (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Standby Letters of Credit	$ 1,536,000	$ 1,551,000
Loan Origination Commitments [Member]
Commitments to Extend Credit	$ 96,374,000	$ 71,359,000

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