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v3.21.1

Note 1 - Summary of Significant Accounting Policies (Details Textual) | 3 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Mar. 31, 2021 USD ($) shares | Mar. 31, 2020 USD ($) | Dec. 31, 2020 USD ($) | Jul. 01, 2020 USD ($) | Dec. 31, 2019 USD ($) | Oct. 01, 2019 USD ($) | Dec. 31, 2006 USD ($)
Participating Interest In Loans, Losses or Charge-offs | $ 0 |  |  |  |  |  |
Impaired Financing Receivable, Recorded Investment, Total | 10,389,000 |  | $ 7,851,000 |  |  |  |
Stock Issued During Period, Value, New Issues | 175,000 | $ 106,000 |  |  |  |  |
Goodwill, Ending Balance | 59,946,000 |  | 60,506,000 |  |  |  |
Valley Ridge Financial Corp. [Member] |  |  |  |  |  |  |
Goodwill, Ending Balance |  |  |  |  |  |  | $ 13,700,000
County Bank Corp ("County") [Member] |  |  |  |  |  |  |
Goodwill, Ending Balance |  |  |  |  | $ 38,900,000 | $ 38,866,000 |
Community Shores Bank Corp ("Community Shores") [Member] |  |  |  |  |  |  |
Goodwill, Ending Balance |  |  | $ 7,300,000 | $ 7,353,000 |  |  |
Goodwill, Purchase Accounting Adjustments | $ (560,000) |  |  |  |  |  |
Directors' Stock Purchase Plan [Member] |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) | shares | 4,732 |  |  |  |  |  |
Stock Issued During Period, Value, New Issues | $ 146,000 |  |  |  |  |  |
Employee Stock Purchase Plan [Member] |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) | shares | 1,201 |  |  |  |  |  |
Stock Issued During Period, Value, New Issues | $ 29,000 |  |  |  |  |  |
Participating Interests in Mortgage Loans [Member] |  |  |  |  |  |  |
Impaired Financing Receivable, Recorded Investment, Total | $ 0 | $ 0 |  |  |  |  |
Credit Concentration Risk [Member] | Participating Interests in Mortgage Loans [Member] |  |  |  |  |  |  |
Number Of Mortgage Bankers | 14 |  |  |  |  |  |
Concentration Risk, Percentage | 22.00% |  |  |  |  |  |
Number of Participating Interest In Loans To Other Financial Institutions Over 30 Days | 12 |  | 26 |  |  |  |
Number of Participating Interest In Loans To Other Financial Institutions | 114 |  | 222 |  |  |  |
Participating Interest In Loans To Other Financial Institutions Over 30 Days | $ 2,100,000 |  | $ 6,400,000 |  |  |  |

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