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Note 8 - Loans and Related Allowance for Credit Losses (Details Textual) Pure in Thousands	3 Months Ended		15 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Number of Days Past Due (Day)			90 days
Financing Receivable, before Allowance for Credit Loss, Total	$ 1,382,847,000		$ 1,382,847,000	$ 1,352,872,000
Financing Receivable, Modified, Accumulated	4,336,000		4,336,000	3,300,000
Financing Receivable, Allowance for Credit Loss, Troubled Debt Restructuring				$ 72,000
Financing Receivable, Nonaccrual, Interest Income	115,000	$ 64,000
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts		0
Threshold For Loans Evaluated For Impairment [Member]
Financing Receivable, before Allowance for Credit Loss, Total	750,000		750,000
Threshold For Loans Evaluated For Impairment [Member] | Outside Consultant [Member]
Financing Receivable, before Allowance for Credit Loss, Total	250,000		250,000
Threshold For Loans Evaluated For Impairment [Member] | Criticized Relationships [Member]
Financing Receivable, before Allowance for Credit Loss, Total	$ 150,000		$ 150,000

X

- Definition

Amount of allowance for credit loss on financing receivable allocated for troubled debt restructurings.

+ References

No definition available.

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X

- Definition

Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

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- Definition

The number of days past due.

+ References

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X

- Definition

Accumulated amortized cost of financing receivable modified for debtor experiencing financial difficulty.

+ References

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-SubTopic 10
-Name Accounting Standards Codification
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- Definition

Amount of interest income on financing receivable on nonaccrual status.

+ References

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-Topic 326
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- Definition

Amortized cost, before allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

+ References

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-Topic 326
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