Loans - Impaired Loans (Details) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018 USD ($) contract	Sep. 30, 2017 USD ($) contract	Sep. 30, 2018 USD ($) contract	Sep. 30, 2017 USD ($) contract	Dec. 31, 2017 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 10,118		$ 10,118		$ 5,205
Impaired Financing Receivable, Unpaid Principal Balance	10,167		10,167		5,263
Impaired Financing Receivable, Related Allowance	0		0		0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	9,221	$ 5,728	6,937	$ 3,944
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	637	80	806	80
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	50	0	46
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	0	0	0	0
Impaired Financing Receivable, Average Recorded Investment	9,221	5,778	6,937	3,990
Impaired Financing Receivable, Interest Income, Accrual Method	637	80	806	80
Other real estate owned	5,041		5,041		5,041
Mortgage loans in process of foreclosure, amount	0		0		200
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	7,949		7,949		3,886
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	7,949		7,949		3,886
Impaired Financing Receivable Loans With No Specific Related Allowance	0		0		0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	7,233	3,941	5,430	2,157
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	561	71	723	71
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	50	0	46
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method	$ 0	$ 0	$ 0	$ 0
Number of contracts classified as TDRs \| contract	0	2	0	2
Pre-modification recorded investment	$ 1,800		$ 1,800
Post-modification recorded investment	1,800		1,800
Owner-occupied commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,479		1,479		7
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,479		1,479		7
Impaired Financing Receivable Loans With No Specific Related Allowance	0		0		0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,249	$ 4	553	$ 1
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	75	0	82	0
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	579		579		1,139
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	579		579		1,144
Impaired Financing Receivable Loans With No Specific Related Allowance	0		0		0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	573	1,690	768	1,673
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	7	0	7
Other real estate owned	600		600		600
Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0		0		83
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0		0		83
Impaired Financing Receivable Loans With No Specific Related Allowance	0		0		0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	62	0	76	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	0	0	0	0
Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	111		111		90
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	160		160		143
Impaired Financing Receivable Loans With No Specific Related Allowance	0		0		$ 0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	104	93	110	113
Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method	$ 1	$ 2	$ 1	$ 2

Amount of allowance for credit losses related to recorded investment not with a specific valuation allowance.

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Number of financing receivables that have been modified by troubled debt restructurings.

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Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of allowance for credit losses related to recorded investment.

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Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

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Amount of average investment of impaired financing receivables for which there is no related allowance for credit losses.

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Amount of interest income, recognized on accrual basis, on financing receivables that are recognized as impaired, for which there is no related allowance for credit losses.

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Amount of unpaid principal balance of impaired financing receivables for which there is no related allowance for credit losses.

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Amount of average investment of impaired financing receivables for which there is a related allowance for credit losses.

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Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

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-Publisher FASB
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Carrying amount of other real estate not separately disclosed, including, but not limited to, real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. This does not include real estate assets taken in settlement of troubled loans through surrender or foreclosure.

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