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Note 8 - Business Combination (Details Textual) |  |  | 3 Months Ended | 9 Months Ended
--- | --- | --- | --- | ---
Jul. 01, 2020 USD ($) shares | Oct. 01, 2019 USD ($) shares | Sep. 30, 2020 USD ($) | Sep. 30, 2020 USD ($)
Stock Issued During Period, Value, Acquisitions |  |  | $ 15,493,000 | $ 15,494,000
County Bank Corp ("County") [Member] |  |  |  |
Number of Branch Offices |  | 14 |  |
Number of Loan Office |  | 1 |  |
Community Shores Bank Corp ("Community Shores") [Member] |  |  |  |
Number of Branch Offices | 4 |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets, Total | $ 244,535,000 |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Total Loans | 174,800,000 |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Total Deposits | $ 227,832,000 |  |  |
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares) | shares | 524,139 |  |  |
Business Acquisition, Equity Interest Issued or Issuable, Number of Fractional Shares (in shares) | shares | 84 |  |  |
Payments to Acquire Businesses, Gross | $ 5,390,000 |  |  |
Business Combination, Consideration Transferred, Total | $ 20,881,000 |  |  |
County Bank Corp ("County") [Member] |  |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets, Total |  | $ 672,762,000 |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Total Loans |  | 424,000,000 |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Total Deposits |  | 573,601,000 |  |
Business Combination, Consideration Transferred, Total |  | $ 107,945,000 |  |
County Bank Corp ("County") [Member] | Common Stock [Member] |  |  |  |
Stock Issued During Period, Shares, Acquisitions (in shares) | shares |  | 3,603,872 |  |
Stock Issued During Period, Value, Acquisitions |  | $ 108,000,000 |  |
County Bank Corp ("County") [Member] | Fractional Stock [Member] |  |  |  |
Stock Issued During Period, Shares, Acquisitions (in shares) | shares |  | 299 |  |

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