Income Taxes - Reconciliation of income tax rate (Details)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of U.S. federal statutory tax rate and effective income tax rate
U.S. federal statutory rate (as a percentage)	21.00%	21.00%	21.10%
Effect of:
State taxes, net of federal benefit (as a percentage)	6.60%	8.50%	4.00%
Non-deductible items	1.50%		9.50%
Income on cash surrender value of bank-owned life insurance (as a percentage)	(0.40%)	0.60%	(0.20%)
Other, net (as a percentage)	0.50%	1.20%	0.40%
Effective tax rate (as a percentage)	29.20%	31.30%	34.80%

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32687-109319

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

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.Fact.4)
-URI http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

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-Publisher FASB
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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 life insurance expense.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.Fact.4)
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32687-109319

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Percentage of the difference, between reported income tax expense (benefit) and the expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, that is attributable to tax exempt income, equity in earnings (loss) of an unconsolidated subsidiary, minority interest income (expense), tax holiday, disposition of a business, disposition of an asset, repatriation of foreign earnings, repatriation of foreign earnings jobs creation act of 2004, change in enacted tax rate, prior year income taxes, change in deferred tax asset valuation allowance, and other adjustments.

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