Note 12 - Commitments and Contingencies (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019
Operating Lease, Weighted Average Discount Rate, Percent	4.50%
Operating Lease, Weighted Average Remaining Lease Term (Year)	4 years 6 months	2 years 1 month 6 days
Lease, Cost, Total	$ 407,000	$ 465,000
Operating Lease, Cost	312,000	308,000
Short-term Lease, Cost	76,000	114,000
Variable Lease, Cost	19,000	43,000
Operating Leases, Rent Expense, Net, Total			$ 348,000
Operating Lease, Payments	$ 308,000
Consumer Loan Commitments as Percentage of Aggregate Commitments	7.00%
Commercial and Agricultural Loan Commitments as Percentage of Aggregate Commitments	36.00%
Real Estate Loan Commitments as Percentage of Aggregate Commitments	57.00%
Maximum Loan to Value Ratio	80.00%
Occupancy and Equipment Expense [Member]
Operating Lease, Expense	$ 388,000	$ 422,000	$ 340,000
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset				$ 565,000