Note 3 - Investment Securities (Details Textual)			3 Months Ended	6 Months Ended
		May 31, 2021 USD ($)	Mar. 31, 2022 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Mar. 07, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Securities, Held-to-Maturity, Number of Securities							0
Debt Securities, Held-to-Maturity, Allowance for Credit Loss, Ending Balance				$ 0			$ 0
Debt Securities, Held-to-Maturity, Nonaccrual				0
Debt Securities, Held-to-Maturity, Accrued Interest, after Allowance for Credit Loss				2,000,000			$ 0
Debt Securities, Available-for-sale, Number of Positions Sold			3
Proceeds from Sale of Debt Securities, Available-for-sale		$ 91,000,000	$ 2,000,000	2,111,000	$ 91,094,000
Debt Securities, Available-for-Sale, Gain (Loss), Total			$ (92,000)
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Ending Balance				$ 0
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions				540			227
Collateral Pledged [Member]
Debt Securities, Available-for-Sale, Restricted				$ 1,040,000.00			$ 879,000,000
Commonwealth [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities	[1]					$ 246,793,000
Other Assets [Member]
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Total				3,000,000			$ 3,000,000
Debt Securities, Held-to-Maturity, Accrued Interest, after Allowance for Credit Loss				$ 2,000,000

[1] As of acquisition date, securities with a fair value of $162 million were classified by Bancorp as HTM.