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Loans and Allowance for Loan Losses - Troubled Debt Restructuring by Class (Details)	Sep. 30, 2020 USD ($) loan	Dec. 31, 2019 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in troubled debt restructurings	$ 12,625,000	$ 11,333,000
Troubled debt restructuring, loans acquired, number of loans | loan	1
Troubled debt restructuring, loans acquired	$ 276,000	0
Financing receivable, modifications, recorded investment, nonaccrual status	300,000	58,000
Commercial loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in troubled debt restructurings	1,017,000	1,223,000
Commercial real estate loans | Commercial real estate, owner-occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in troubled debt restructurings	7,003,000	6,998,000
Commercial real estate loans | Commercial real estate, investor-owned
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in troubled debt restructurings	3,309,000	1,770,000
Residential loans | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in troubled debt restructurings	527,000	251,000
Residential loans | Other residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in troubled debt restructurings	0	452,000
Consumer loans | Installment and other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in troubled debt restructurings	$ 769,000	$ 639,000

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Amount of financing receivable modified as troubled debt restructuring.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

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