Loans and Allowance - Past Due Financing Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 266,439	$ 258,264
Non-accrual	3,270	3,751	$ 3,780
Total	271,612	265,058
30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,843	3,007
Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	60	36
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	15,823	14,243
Non-accrual	185	403	623
Total	16,112	14,739
Consumer \| 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	80	93
Consumer \| Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	24
Residential Real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	79,205	89,201
Non-accrual	2,124	2,508	2,508
Total	81,926	93,468
Residential Real estate \| 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	597	1,759
Indirect
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	83,932	70,392
Non-accrual	88	193	349
Total	85,186	71,656
Indirect \| 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,166	1,071
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	11,203	12,349
Non-accrual	48
Total	11,257	12,351
Commercial \| Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	6	2
Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	3,188	4,279
Non-accrual	318
Total	3,536	4,397
Construction \| 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due		84
Construction \| Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	30	34
Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	73,088	67,800
Non-accrual	507	647	$ 300
Total	$ 73,595	$ 68,447

Financing receivables that are current.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953401-111524

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Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5111-111524

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Recorded Investment in financing receivables that are past due at the balance sheet date.

+ References

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

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