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Note 12 - Regulatory Matters (Details Textual) - USD ($) $ / shares in Units, $ in Millions |  |  |  |  |  |  |  |  | 3 Months Ended | 9 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 15, 2021 | Oct. 14, 2021 | Sep. 15, 2021 | Jul. 15, 2021 | Jun. 16, 2021 | Apr. 15, 2021 | Mar. 17, 2021 | Jan. 14, 2021 | Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | May 31, 2021 | Dec. 31, 2020 | May 31, 2019 | Dec. 31, 2009
Preferred Securities of Subsidiary Trust |  |  |  |  |  |  |  |  | $ 46.0 |  | $ 46.0 |  |  | $ 45.5 |  |
Maximum Restricted Core Element Allowed in Tier One Capital Percent |  |  |  |  |  |  |  |  |  |  | 25.00% |  |  |  |  |
Maximum Level of Consolidated Aggregate Assets Allowing for Inclusion of Trust Preferred Securities in Tier One Capital |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 15,000.0
Trust Preferred Securities Included in Tier One Capital |  |  |  |  |  |  |  |  | $ 46.0 |  | $ 46.0 |  |  | $ 45.5 |  |
Capital Conservation Buffer |  |  |  |  |  |  |  |  | 2.50% |  | 2.50% |  |  |  |  |
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy to Risk Weighted Assets |  |  |  |  |  |  |  |  | 0.070 |  | 0.070 |  |  |  |  |
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets |  |  |  |  |  |  |  |  | 0.085 |  | 0.085 |  |  |  |  |
Capital Required for Capital Adequacy to Risk Weighted Assets |  |  |  |  |  |  |  |  | 0.105 |  | 0.105 |  |  |  |  |
Common Stock, Dividends, Per Share, Declared (in dollars per share) |  |  |  | $ 0.30 |  | $ 0.29 |  | $ 0.29 |  |  |  |  |  |  |  |
Common Stock, Dividends, Per Share, Cash Paid (in dollars per share) |  |  | $ 0.30 |  | $ 0.29 |  | $ 0.29 |  | $ 0.30 | $ 0.28 | $ 0.88 | $ 0.84 |  |  |  |
Stock Repurchase Program, Authorized Amount |  |  |  |  |  |  |  |  |  |  |  |  | $ 20.0 |  | $ 20.0 |
Stock Repurchased During Period, Shares (in shares) |  |  |  |  |  |  |  |  |  |  | 636,000 |  |  |  |  |
Stock Repurchased During Period, Value |  |  |  |  |  |  |  |  |  |  | $ 19.8 |  |  |  |  |
Treasury Stock Acquired, Average Cost Per Share (in dollars per share) |  |  |  |  |  |  |  |  |  |  | $ 31.14 |  |  |  |  |
Stock Repurchase Program, Remaining Authorized Repurchase Amount |  |  |  |  |  |  |  |  | $ 8.4 |  | $ 8.4 |  |  |  |  |
Forecast [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common Stock, Dividends, Per Share, Cash Paid (in dollars per share) | $ 0.30 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common Stock, Dividends, Per Share, Declared (in dollars per share) |  | $ 0.30 |  |  |  |  |  |  |  |  |  |  |  |  |  |

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- Definition An additional amount held in risk-based capital designed to ensure that banks build up capital buffers outside periods of stress which can be drawn down as losses are incurred. The requirement is based on simple capital conservation rules designed to avoid breaches of minimum capital requirements. + References No definition available. + Details
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- Definition The minimum common equity tier one capital ratio (common equity tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action. + References No definition available. + Details
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- Definition The maximum level of consolidated aggregate assets allowing for inclusion of trust preferred securities in Tier 1 Capital under the Dodd-Frank Act. + References No definition available. + Details
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- Definition Trust preferred securities held by the trust that are included in Tier One Capital and subject to certain limitations. + References No definition available. + Details
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- Definition Ratio of minimum total risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958570-112826 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
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