Note 4 - Allowance for Loan Losses and Reserve for Unfunded Lending Commitments (Details Textual) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021		Mar. 31, 2021	Dec. 31, 2021		Dec. 31, 2020
Loans and Leases Receivable, Allowance, Ending Balance	$ 17,988	$ 18,678	[1]	$ 21,416	$ 18,678	[1]	$ 21,403
Financing Receivable, Credit Loss, Expense (Reversal)	(758)	(2,800)		$ (0)	(2,825)
SBA CARES Act Paycheck Protection Program [Member]
Loans and Leases Receivable, Allowance, Ending Balance	$ 0	$ 0			$ 0

[1] Derived from audited consolidated financial statements