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Note 1 - Significant Accounting Policies (Details Textual) | 3 Months Ended | 6 Months Ended |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jun. 30, 2022 USD ($) shares | Jun. 30, 2021 USD ($) shares | Jun. 30, 2022 USD ($) shares | Jun. 30, 2021 USD ($) shares | Mar. 31, 2022 USD ($) | Jan. 01, 2022 USD ($) | Dec. 31, 2021 USD ($) | May 31, 2021 USD ($) | Mar. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Aug. 08, 2020 USD ($)
Number of Unconsolidated Business Trusts Formed to Issue Trust Preferred Securities | 5 |  | 5 |  |  |  |  |  |  |  |
Financing Receivable, before Allowance for Credit Loss, Total | $ 3,723,800,000 |  | $ 3,723,800,000 |  |  |  | $ 3,453,459,000 |  |  |  |
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Ending Balance | 0 |  | 0 |  |  |  |  |  |  |  |
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Total | 2,200,000 |  | $ 2,200,000 |  |  |  |  |  |  |  |
Interest Income on Commercial and Mortgage Loans Discontinued Period (Day) |  |  | 90 days |  |  |  |  |  |  |  |
Maximum Delinquency Period for Consumer and Credit Card Loans to be Charged Off (Day) |  |  | 120 days |  |  |  |  |  |  |  |
Mortgages Held-for-sale, Fair Value Disclosure | 13,300,000 |  | $ 13,300,000 |  |  |  | 16,700,000 |  |  |  |
Servicing Asset, Total | 1,370,000,000 |  | 1,370,000,000 |  |  |  | 1,340,000,000 |  |  |  |
Financing Receivable, Allowance for Credit Loss, Ending Balance | 35,974,000 | $ 35,913,000 | 35,974,000 | $ 35,913,000 | $ 35,153,000 |  | 35,363,000 |  | $ 38,695,000 | $ 37,967,000 |
Retained Earnings (Accumulated Deficit), Total | $ 188,452,000 |  | $ 188,452,000 |  |  |  | 174,536,000 |  |  |  |
Core Deposits [Member] |  |  |  |  |  |  |  |  |  |  |
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life (Year) |  |  | 10 years |  |  |  |  |  |  |  |
Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member] |  |  |  |  |  |  |  |  |  |  |
Financing Receivable, Allowance for Credit Loss, Ending Balance |  |  |  |  |  | $ (400,000) | $ (400,000) |  |  |  |
Retained Earnings (Accumulated Deficit), Total |  |  |  |  |  | 300,000 |  |  |  |  |
Cumulative Effect, Period of Adoption, Adjustment [Member] | Accounting Standards Update 2016-13 [Member] | Other Assets [Member] |  |  |  |  |  |  |  |  |  |  |
Deferred Income Tax Assets, Net |  |  |  |  |  | $ 100,000 |  |  |  |  |
Restricted Stock [Member] |  |  |  |  |  |  |  |  |  |  |
Incremental Common Shares Attributable to Participating Nonvested Shares with Non-forfeitable Dividend Rights (in shares) | shares | 325,000 | 262,000 | 325,000 | 262,000 |  |  |  |  |  |  |
Share-Based Payment Arrangement, Option [Member] |  |  |  |  |  |  |  |  |  |  |
Incremental Common Shares Attributable to Participating Nonvested Shares with Non-forfeitable Dividend Rights (in shares) | shares | 1,000 | 3,000 | 1,000 | 3,000 |  |  |  |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) | shares | 6,000 | 7,000 | 6,000 | 7,000 |  |  |  |  |  |  |
SBA, CARES Act, Paycheck Protection Program [Member] |  |  |  |  |  |  |  |  |  |  |
Number of Loans Originated Under the Paycheck Protection Program |  |  |  |  |  |  |  |  |  |  | 2,200
Financing Receivable, before Allowance for Credit Loss, Total |  |  |  |  |  |  |  |  |  |  | $ 553,000,000
Financing Receivable, Not Yet Forgiven, Number of Loans | 12 |  | 12 |  |  |  |  |  |  |  |
Financing Receivable, Not Yet Forgiven | $ 700,000 |  | $ 700,000 |  |  |  |  |  |  |  |
Amortization of Deferred Loan Origination Fees, Net |  |  | $ 100,000 |  |  |  |  |  |  |  |
SBA, CARES Act, Paycheck Protection Program, Round Two [Member] |  |  |  |  |  |  |  |  |  |  |
Number of Loans Originated Under the Paycheck Protection Program |  |  |  |  |  |  |  | 1,200 |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  |  |  |  |  |  |  | $ 209,000,000 |  |  |
Financing Receivable, Not Yet Forgiven, Number of Loans | 9 |  | 9 |  |  |  |  |  |  |  |
Financing Receivable, Not Yet Forgiven | $ 2,200,000 |  | $ 2,200,000 |  |  |  |  |  |  |  |
Amortization of Deferred Loan Origination Fees, Net |  |  | $ 900,000 |  |  |  |  |  |  |  |

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