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Loans and Allowance for Loan Losses - Troubled Debt Restructuring by Class (Details) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2018 USD ($) loan | Dec. 31, 2017 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Number of loans removed from TDR designation | loan | 1 | 0
Recorded investment of loans removed from TDR resignation | $ 150,000 |
Recorded investment in Troubled Debt Restructurings | 16,155,000 | $ 16,520,000
TDR loans on non-accrual status |  | 0
Commercial loans | Commercial and industrial |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | 2,267,000 | 2,165,000
Commercial real estate loans | Commercial real estate, owner-occupied |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | 7,007,000 | 6,999,000
Commercial real estate loans | Commercial real estate, investor |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | 1,854,000 | 2,171,000
Commercial real estate loans | Construction |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | 2,976,000 | 2,969,000
Residential loans | Home equity |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | 347,000 | 347,000
Residential loans | Other residential |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | 992,000 | 1,148,000
Consumer loans | Installment and other consumer |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | $ 712,000 | $ 721,000

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- Definition Financing Receivable, Modifications, Removal From Troubled Debt Restructuring, Number Of Contracts + References No definition available. + Details
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- Definition Financing Receivable, Modifications, Removal From Troubled Debt Restructuring, Recorded Investment + References No definition available. + Details
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- Definition The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554 + Details
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