Loans and Allowance for Loan Losses - Additional Information (Details) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2019 USD ($) Contract	Dec. 31, 2018 USD ($) Contract	Aug. 31, 2018 USD ($)
Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items]
Loans Pledged as Collateral	$ 29,600	$ 27,000
Loans and Leases Receivable, Related Parties, Ending Balance	900	800
Loans and Leases Receivable, Related Parties, Additions	100	500
Loans and Leases Receivable, Related Parties, Proceeds	8	200
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance, Total			$ 2,900
Purchased credit impaired loans			$ 2,831
Certain Loans Acquired in Transfer, Accretable Yield	0	0
Loans	555,338	525,870
Non-accruing loans	1,468	2,759
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest	1,500	2,800
Financing Receivable, Troubled Debt Restructuring	100	200
Impaired loans with no related allowance recorded, carrying amount	1,493	708
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	30	44
Interest Income Recorded	13	27
Financing Receivable, Restructuring Recorded Investment With Nonaccrual Status	18	65
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, Cash Flows Expected to be Collected at Acquisition	$ 0	$ 0
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| Contract	0	0
Loans, allowance for loan losses	$ 5,585	$ 5,055
Restructured Loan Modified through Extended Maturity and Payment Schedule Modification [Member]
Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items]
Financing Receivable, Restructuring Recorded Investment With Nonaccrual Status	500
Loans, allowance for loan losses	1	2
Minimum [Member]
Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items]
Loans Modified in a Troubled Debt Restructuring, Individually Evaluated for Impairment, Principal Balance, Threshold	500
Minimum [Member] \| ALC [Member]
Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items]
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest		50
Financial Asset Acquired With Credit Deterioration [Member]
Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items]
Non-accruing loans	200	500
Impaired loans with no related allowance recorded, carrying amount	200	500
Financial Asset Acquired With Credit Deterioration [Member] \| Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items]
Loans	200	300
Financial Asset Acquired With Credit Deterioration [Member] \| Substandard [Member]
Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items]
Loans	$ 200	$ 500
Real Estate [Member]
Debt Securities Heldtomaturity Allowance For Credit Loss [Line Items]
Percentage of Loan Portfolio	62.90%	63.20%

Financing receivable restructuring recorded investment with non accrual status.

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Interest income recorded.

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Percentage of loan portfolio.

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The aggregate excess of a loan's cash flows expected to be collected over the investor's initial investment in the loan. This relates to loans with deteriorating of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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The undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loan, owed to the investor at the reporting date, whether or not currently due and whether or not any such amounts have been written or charged off by the investor. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of financing receivable modified as troubled debt restructuring.

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Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

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Amount of financing receivable on nonaccrual status.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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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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Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

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Reflects the carrying amount of loans deemed to be questionable as to collection on which no interest is continuing to be recognized.

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For an unclassified balance sheet, reflects the carrying amount of unpaid loan amounts due from related parties at the balance sheet date.

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Reflects the amount of new advances made to related parties in the form of loan and lease receivables.

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Amount of cash inflow from related parties which reduce the amount of loans and leases receivable due from related parties.

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Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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