Income Taxes - Reconciliation between applicable income taxes and statutory federal tax rate (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Tax amount
Taxes at statutory federal income tax rate	$ 3,598	$ 4,894	$ 10,993	$ 9,491
Tax effect of tax exempt income	(134)	(134)	(434)	(382)
Tax effect of other	600	888	1,811	1,589
Total income tax expense	$ 4,064	$ 5,648	$ 12,370	$ 10,698
Percentage of pretax income
Taxes at statutory federal income tax rate (as percentage)	21.00%	21.00%	21.00%	21.00%
Tax effect of tax exempt income (as percentage)	(0.80%)	(0.60%)	(0.80%)	(0.80%)
Tax effect of other (as percentage)	3.50%	3.80%	3.50%	3.50%
Applicable income taxes (as percentage)	23.70%	24.20%	23.70%	23.70%

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

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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Amount 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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