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Loans and Allowance for Loan Losses - Troubled Debt Restructuring by Class (Details) | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2017 USD ($) loan | Dec. 31, 2016 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Number of loans removed from TDR designation | loan | 0 | 0
Recorded investment in Troubled Debt Restructurings | $ 16,384,000 | $ 18,168,000
Accruing TDR loans | 0 | 0
Commercial loans | Commercial and industrial |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | 2,050,000 | 2,207,000
Commercial real estate loans | Commercial real estate, owner-occupied |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | 6,999,000 | 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 | 2,193,000 | 2,256,000
Commercial real estate loans | Construction |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | 2,969,000 | 3,245,000
Residential loans | Home equity |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | 348,000 | 625,000
Residential loans | Other residential |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | 1,159,000 | 1,965,000
Consumer loans | Installment and other consumer |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Recorded investment in Troubled Debt Restructurings | $ 666,000 | $ 877,000

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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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