Note 10 - Leases (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating Lease, Weighted Average Remaining Lease Term (Year)	12 years 120 days	12 years 306 days
Operating Lease, Weighted Average Discount Rate, Percent	3.51%	3.49%
Operating Lease, Cost	$ 48,000	$ 48,000
Premises and Equipment [Member]
Operating Lease, Right-of-Use Asset	1,300,000	1,500,000
Other Liabilities [Member]
Operating Lease, Liability, Total	$ 1,510,000	$ 1,700,000