Loans and Allowance - Current, past due, and non-accrual loans by categories of loans and restructured loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 279,768	$ 295,421
Non-accrual	4,127	1,947	$ 3,270
Total	284,738	299,120
30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	822	1,726
Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	21	26
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	11,865	12,669
Non-accrual	137	186	185
Total	12,076	13,071
Consumer \| 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	74	216
Residential Real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	80,192	80,923
Non-accrual	728	956	2,124
Total	81,033	82,637
Residential Real estate \| 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	92	732
Residential Real estate \| Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	21	26
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	81,033	82,637
Indirect
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	101,605	115,890
Non-accrual	123	116	88
Total	102,384	116,698
Indirect \| 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	656	692
Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	3,317	2,317
Non-accrual			318
Total	3,317	2,317
Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	70,882	69,451
Non-accrual	3,139	662	507
Total	74,021	70,113
Commercial Mortgage Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	11,907	14,171
Non-accrual		27	$ 48
Total	$ 11,907	14,284
Commercial Mortgage Portfolio Segment \| 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due		$ 86

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Amount of financing receivable on nonaccrual status.

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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.

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