Loans and Allowance for Loan Losses, Impaired Loans by Portfolio Segment (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2018	Dec. 31, 2017
Recorded Investment [Abstract]
Recorded investment, total	$ 8,103	$ 10,862
Unpaid Principal Balance [Abstract]
Unpaid principal balance, total	8,195	10,988
Related Allowance [Abstract]
Related allowance	540	912
Average Recorded Investment [Abstract]
Average recorded investment, total	9,070	11,223
Interest Income Recognized [Abstract]
Interest income recognized, total	$ 229	431
Threshold term for payment delay to be considered insignificant	30 days
Threshold percentage for shortfall in payment to be considered insignificant	5.00%
Commercial and Industrial [Member]
Recorded Investment [Abstract]
Recorded investment, with no specific allowance recorded	$ 71	0
Recorded investment, with an allowance recorded	469	758
Recorded investment, total	540	758
Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no specific allowance recorded	74	0
Unpaid principal balance, with an allowance recorded	501	788
Unpaid principal balance, total	575	788
Related Allowance [Abstract]
Related allowance	185	247
Average Recorded Investment [Abstract]
Average recorded investment, with no specific allowance recorded	89	0
Average recorded investment, with an allowance recorded	591	791
Average recorded investment, total	680	791
Interest Income Recognized [Abstract]
Interest income recognized, with no specific allowance recorded	2	0
Interest income recognized, with an allowance recorded	16	29
Interest income recognized, total	18	29
Commercial Real Estate [Member]
Recorded Investment [Abstract]
Recorded investment, with no specific allowance recorded	1,396	2,383
Recorded investment, with an allowance recorded	2,187	1,248
Recorded investment, total	3,583	3,631
Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no specific allowance recorded	1,396	2,383
Unpaid principal balance, with an allowance recorded	2,201	1,248
Unpaid principal balance, total	3,597	3,631
Related Allowance [Abstract]
Related allowance	282	257
Average Recorded Investment [Abstract]
Average recorded investment, with no specific allowance recorded	1,422	2,429
Average recorded investment, with an allowance recorded	2,369	1,256
Average recorded investment, total	3,791	3,685
Interest Income Recognized [Abstract]
Interest income recognized, with no specific allowance recorded	57	124
Interest income recognized, with an allowance recorded	30	58
Interest income recognized, total	87	182
Construction and Land [Member]
Recorded Investment [Abstract]
Recorded investment, with no specific allowance recorded	2,694	1,829
Recorded investment, with an allowance recorded	0	3,405
Recorded investment, total	2,694	5,234
Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no specific allowance recorded	2,693	1,881
Unpaid principal balance, with an allowance recorded	0	3,433
Unpaid principal balance, total	2,693	5,314
Related Allowance [Abstract]
Related allowance	0	357
Average Recorded Investment [Abstract]
Average recorded investment, with no specific allowance recorded	3,296	2,041
Average recorded investment, with an allowance recorded	0	3,451
Average recorded investment, total	3,296	5,492
Interest Income Recognized [Abstract]
Interest income recognized, with no specific allowance recorded	110	56
Interest income recognized, with an allowance recorded	0	134
Interest income recognized, total	110	190
Student [Member]
Recorded Investment [Abstract]
Recorded investment, with no specific allowance recorded	0	0
Recorded investment, with an allowance recorded	0	0
Recorded investment, total	0	0
Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no specific allowance recorded	0	0
Unpaid principal balance, with an allowance recorded	0	0
Unpaid principal balance, total	0	0
Related Allowance [Abstract]
Related allowance	0	0
Average Recorded Investment [Abstract]
Average recorded investment, with no specific allowance recorded	0	0
Average recorded investment, with an allowance recorded	0	0
Average recorded investment, total	0	0
Interest Income Recognized [Abstract]
Interest income recognized, with no specific allowance recorded	0	0
Interest income recognized, with an allowance recorded	0	0
Interest income recognized, total	0	0
Residential Real Estate [Member]
Recorded Investment [Abstract]
Recorded investment, with no specific allowance recorded	713	581
Recorded investment, with an allowance recorded	0	0
Recorded investment, total	713	581
Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no specific allowance recorded	730	585
Unpaid principal balance, with an allowance recorded	0	0
Unpaid principal balance, total	730	585
Related Allowance [Abstract]
Related allowance	0	0
Average Recorded Investment [Abstract]
Average recorded investment, with no specific allowance recorded	723	591
Average recorded investment, with an allowance recorded	0	0
Average recorded investment, total	723	591
Interest Income Recognized [Abstract]
Interest income recognized, with no specific allowance recorded	14	22
Interest income recognized, with an allowance recorded	0	0
Interest income recognized, total	14	22
Home Equity Lines of Credit [Member]
Recorded Investment [Abstract]
Recorded investment, with no specific allowance recorded	0	70
Recorded investment, with an allowance recorded	573	588
Recorded investment, total	573	658
Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no specific allowance recorded	0	70
Unpaid principal balance, with an allowance recorded	600	600
Unpaid principal balance, total	600	670
Related Allowance [Abstract]
Related allowance	73	51
Average Recorded Investment [Abstract]
Average recorded investment, with no specific allowance recorded	0	70
Average recorded investment, with an allowance recorded	580	594
Average recorded investment, total	580	664
Interest Income Recognized [Abstract]
Interest income recognized, with no specific allowance recorded	0	3
Interest income recognized, with an allowance recorded	0	5
Interest income recognized, total	0	8
Consumer [Member]
Recorded Investment [Abstract]
Recorded investment, with no specific allowance recorded	0	0
Recorded investment, with an allowance recorded	0	0
Recorded investment, total	0	0
Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no specific allowance recorded	0	0
Unpaid principal balance, with an allowance recorded	0	0
Unpaid principal balance, total	0	0
Related Allowance [Abstract]
Related allowance	0	0
Average Recorded Investment [Abstract]
Average recorded investment, with no specific allowance recorded	0	0
Average recorded investment, with an allowance recorded	0	0
Average recorded investment, total	0	0
Interest Income Recognized [Abstract]
Interest income recognized, with no specific allowance recorded	0	0
Interest income recognized, with an allowance recorded	0	0
Interest income recognized, total	$ 0	$ 0

Related Allowance [Abstract]

No definition available.

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- Definition

Percentage shortfall in the required principal and interest payments on a loan on non-accrual status to be considered insignificant and would not indicate an impairment situation, if in management's judgment the loan will be paid in full,

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Period of time for a delay in payment of a loan on non-accrual status to be considered insignificant and would not indicate an impairment situation, if in management's judgment the loan will be paid in full, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
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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 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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