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Note 1 - Summary of Significant Accounting Policies (Details Textual) |  | 12 Months Ended |
--- | --- | --- | ---
Jan. 01, 2018 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Jan. 01, 2019 USD ($)
Number of Branches |  | 16 |  |
Servicing Asset at Fair Value, Amount, Ending Balance |  | $ 70,800,000 | $ 59,400,000 |
Goodwill, Impairment Loss |  | 0 | 0 |
Finance Lease, Right-of-Use Asset |  | 4,012,000 |  |
Tax Cuts and Jobs Act, Reclassification from AOCI to Retained Earnings, Tax Effect | $ 187,000 |  |  |
Finance Lease, Liability, Total |  | 4,098,000 |  |
Operating Lease, Right-of-Use Asset |  | $ 903,000 |  |
Accounting Standards Update 2016-01 [Member] |  |  |  |
Reclassification of AOCI and Retained Earnings | $ 141,000 |  |  |
Accounting Standards Update 2016-02 [Member] |  |  |  |
Finance Lease, Right-of-Use Asset |  |  |  | $ 3,800,000
Operating Lease, Liability, Total |  |  |  | 1,100,000
Finance Lease, Liability, Total |  |  |  | 3,800,000
Operating Lease, Right-of-Use Asset |  |  |  | $ 1,100,000
Core Deposits [Member] |  |  |  |
Finite-Lived Intangible Asset, Useful Life |  | 10 years |  |
Furniture and Fixtures [Member] | Minimum [Member] |  |  |  |
Property, Plant and Equipment, Useful Life |  | 3 years |  |
Furniture and Fixtures [Member] | Maximum [Member] |  |  |  |
Property, Plant and Equipment, Useful Life |  | 20 years |  |
Building and Building Improvements [Member] | Minimum [Member] |  |  |  |
Property, Plant and Equipment, Useful Life |  | 3 years |  |
Building and Building Improvements [Member] | Maximum [Member] |  |  |  |
Property, Plant and Equipment, Useful Life |  | 40 years |  |

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