Note 4 - Loans and the Allowance for Credit Losses - Summary of (Reversal of) Provision for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Provision for (reversal of) credit losses - loans	$ 3,300	$ 10,000	$ 3,000	$ 1,450	$ 815	$ 1,100	$ (1,649)	$ (5,766)	$ 17,066	$ (5,018)	$ 41,000
Provision for (reversal of) credit losses									17,750	(5,500)	$ 41,000
Unfunded Loan Commitment [Member]
Provision for (reversal of) credit losses - unfunded commitments									$ 684	$ (482)

Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

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- Definition

Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

+ References

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- Definition

Amount of credit loss expense (reversal of expense) for financing receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
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