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Loans and Allowance for Loan Losses - Troubled Debt Restructuring by Class (Details)	6 Months Ended
	Jun. 30, 2019 USD ($) loan	Jun. 30, 2018 USD ($) loan	Dec. 31, 2018 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment of loans removed from TDR resignation	$ 3,000	$ 150,000
Recorded investment in Troubled Debt Restructurings	12,090,000		$ 14,406,000
TDR loans acquired	0		0
TDR loans on non-accrual status	$ 361,000		65,000
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans removed from TDR designation | loan	1
Commercial loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in Troubled Debt Restructurings	$ 1,433,000		1,506,000
Commercial real estate loans | Commercial real estate, owner-occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in Troubled Debt Restructurings	7,000,000		6,993,000
Commercial real estate loans | Commercial real estate, investor
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in Troubled Debt Restructurings	1,796,000		1,821,000
Commercial real estate loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in Troubled Debt Restructurings	488,000		2,688,000
Residential loans | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in Troubled Debt Restructurings	251,000		251,000
Residential loans | Other residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans removed from TDR designation | loan		1
Recorded investment in Troubled Debt Restructurings	457,000		462,000
Consumer loans | Installment and other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in Troubled Debt Restructurings	$ 665,000		$ 685,000

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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=118936363&loc=SL6953676-111524

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-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=118939409&loc=d3e18845-111554

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