Note 4 - Pooled Trust Preferred Securities (Details) $ in Thousands	12 Months Ended
Dec. 31, 2021 USD ($) bank InsuranceCompany	Dec. 31, 2020 USD ($)
Schedule Of Available For Sale Securities [Line Items]
Investment securities available-for-sale, amortized cost	$ 697,094	$ 428,495
Fair value	$ 692,360	$ 435,646
PreTSL IV [Member]
Schedule Of Available For Sale Securities [Line Items]
Class	Mezzanine
Investment securities available-for-sale, amortized cost	$ 83
Fair value	75
Unrealized gains (losses)	(8)
Realized OTTI credit loss	0
Total recognized OTTI credit loss	$ (1)
Moody's ratings	Ba1
Current number of performing banks \| bank	3
Current number of performing insurance companies \| InsuranceCompany	0
Actual deferrals and defaults as a % of total collateral	0.00%
Total performing collateral as a % of outstanding bonds	238.20%

Class of pooled trust preferred security owned.

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Current number of performing banks.

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Current number of performing insurance companies.

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Realized other than temporary impairment losses, investments.

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Description of the credit rating indicative of likelihood of repayment of the debt instrument given by a credit rating agency (for example, Standard and Poor's, Moody's, Fitch).

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Amount, before tax, of unrealized gain (loss) in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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This item represents the loan to collateral ratio of the underlying assets in the security, represented as a percentage, which was considered as one of the potential factors in reaching a conclusion that the available-for-sale investments are other than temporarily impaired and only the amount of impairment related to credit loss was recognized in earnings.

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Amount, before tax, of other-than-temporary impairment (OTTI) on investment in debt security measured at amortized cost (held-to-maturity), recognized in earnings.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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