Note 10 - Income Taxes - Effective Tax Rate Reconciliation (Details)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Federal statutory income tax rate	21.00%	21.00%
State taxes, net of federal tax benefit	8.60%	8.60%
Tax exempt interest on municipal securities and loans	(3.20%)	(3.50%)
Other	(1.20%)	(1.30%)
Effective tax rate	25.20%	24.80%

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other adjustments.

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