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Note 10 - Federal Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Tax at statutory rate	$ 11,518,000	$ 12,697,000	$ 10,883,000
Tax-exempt interest	(681,000)	(644,000)	(620,000)
Bank owned life insurance	(238,000)	(804,000)	(201,000)
Change in valuation allowance	(94,000)	0	0
Other	205,000	(245,000)	(264,000)
Tax expense	$ 10,710,000	$ 11,004,000	$ 9,798,000

X

- Definition

Amount of the difference between reported income tax expense (benefit) and expected tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from bank owned life insurance that is exempt from income taxes.

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

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