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Note 13 - Commitments and Off-balance-sheet Risk (Tables) | 12 Months Ended
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Dec. 31, 2020
Notes Tables |
Summary of Contractual Amounts of Financial Instruments With Off Balance Sheet Risk [Table Text Block] |
|  | 2020 |  |  | 2019 |
Commercial unused lines of credit |  | $ | 1,019,496,000 |  |  | $ | 776,493,000 |
Unused lines of credit secured by 1 – 4 family residential properties |  |  | 59,396,000 |  |  |  | 60,858,000 |
Credit card unused lines of credit |  |  | 72,495,000 |  |  |  | 58,199,000 |
Other consumer unused lines of credit |  |  | 30,707,000 |  |  |  | 18,135,000 |
Commitments to make loans |  |  | 227,558,000 |  |  |  | 101,961,000 |
Standby letters of credit |  |  | 20,543,000 |  |  |  | 22,798,000 |
Total commitments |  | $ | 1,430,195,000 |  |  | $ | 1,038,444,000 |
Schedule of Fair Value, Off-balance Sheet Risks [Table Text Block] |
|  | 2020 |  |  | 2019 |
|  | Contract |  |  | Carrying |  |  | Contract |  |  | Carrying |
|  | Amount |  |  | Value |  |  | Amount |  |  | Value |
Standby letters of credit |  | $ | 20,543,000 |  |  | $ | 138,000 |  |  | $ | 22,798,000 |  |  | $ | 160,000 |

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