Note 1 - Summary of Accounting Policies (Details Textual) $ / shares in Thousands			12 Months Ended
	Jan. 01, 2018 USD ($)	Jul. 03, 2008 shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Jan. 01, 2019 USD ($)
Conversion of Stock Shares Converted for Each Outstanding Share of Wholly Owned Subsidiary		1
Common Stock, Shares Authorized			50,000,000	50,000,000
Common Stock, Shares, Issued, Total			8,210,147	8,194,805
Preferred Stock, Shares Authorized			10,000,000
Preferred Stock, Shares Issued, Total			0
Operating Lease, Right-of-Use Asset | $			$ 4,312,000	$ 0
Advertising Expense | $			304,000	237,000
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax, Total | $			$ 97,000	$ 57,000
Number of Forms of Outstanding Stock Awards				2
Stock Issued During Period, Shares, Restricted Stock Award, Gross			26,095	96,650
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross			0	0
Common Stock, No Par Value | $ / shares			$ 0	$ 0
Common Stock, Shares, Outstanding, Ending Balance			8,210,147	8,194,805
Preferred Stock, No Par Value | $ / shares			$ 0
Preferred Stock, Shares Outstanding, Ending Balance			0
Accounting Standards Update 2018-02 [Member] | Retained Earnings [Member]
Reclassification from AOCI to Retained Earnings Tax Effect | $	$ (163,000)
Accounting Standards Update 2018-02 [Member] | AOCI Attributable to Parent [Member]
Reclassification from AOCI to Retained Earnings Tax Effect | $	$ 163,000
Core Deposits [Member]
Finite-Lived Intangible Asset, Useful Life				10 years
Impairment of Intangible Assets (Excluding Goodwill), Total | $				$ 0
Interest Payable and Other Liabilities [Member]
Operating Lease, Liability, Total | $					$ 5,246,000
Interest Receivable and Other Assets [Member]
Operating Lease, Right-of-Use Asset | $					$ 4,817,000