Note 8 - Borrowed Funds (Details Textual) - USD ($) $ in Thousands					12 Months Ended
	Mar. 28, 2019	Nov. 23, 2014	Mar. 13, 2014	Nov. 23, 2004	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Securities Sold under Agreements to Repurchase, Total						$ 0
Advances from Federal Home Loan Banks, Total					$ 20,000	150,000
Threshold for Deferred Bonus				$ 225,000
Amount of Deferred Bonus Accrued in Other Liabilities			$ 300	$ 610
Accrued Interest on Deferred Bonus	5.72%	5.06%	5.02%	7.00%
Interest Expense, Other					110	105	$ 99
Accrued Bonuses					2,100	2,100
Junior Subordinated Notes, Noncurrent					$ 119,100	$ 119,100
Junior Subordinated Debt [Member]
Debt Instrument, Term (Year)					30 years
Debt Instrument, Interest Rate, Effective Percentage					2.38%	2.40%
Interest Expense, Debt, Total					$ 2,800	$ 3,600	5,600
Mature in May 2023 [Member]
Advances from Federal Home Loan Banks, Total					20,000
Ten-year Treasury Note [Member]
Debt Instrument, Basis Spread on Variable Rate		2.75%
Debt Instrument, Term (Year)		10 years
Five-year Treasury Note [Member]
Debt Instrument, Basis Spread on Variable Rate	3.50%
Debt Instrument, Term (Year)	5 years
Over-night Borrowings [Member]
Advances from Federal Home Loan Banks, Total					0	0	$ 0
Non Overnight Borrowings [Member]
Advances from Federal Home Loan Banks, Total					$ 20,000	$ 150,000
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Interest Rate					2.89%	2.15%