Note 5 - Premises, Equipment and Leases (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Depreciation, Depletion and Amortization, Total	$ 1,406,000	$ 1,388,000
Operating Lease, Weighted Average Remaining Lease Term (Year)	12 years 164 days	12 years 361 days
Operating Lease, Weighted Average Discount Rate, Percent	3.51%	3.49%
Operating Lease, Cost	$ 192,000	$ 194,000
Other Assets [Member]
Operating Lease, Right-of-Use Asset	1,400,000	1,500,000
Other Liabilities [Member]
Operating Lease, Liability, Total	$ 1,551,000	$ 1,700,000