Loans - Schedule of Analysis of Past due Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	$ 325,617	$ 330,359
Total Loans	325,992	331,598
Nonaccrual Loans	$ 1,017	$ 1,287
Total non-accrual loans to total loans	0.31%	0.39%
Total non-accrual loans to total assets	0.19%	0.25%
Commercial Real Estate [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	$ 185,223	$ 189,050
Total Loans	185,223	189,291
Commercial Land Development [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	1,400	1,492
Total Loans	1,400	1,492
Commercial Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	38,127	46,151
Total Loans	38,160	46,184
Residential Real Estate First Mortgages [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	80,319	68,147
Total Loans	80,661	68,968
Nonaccrual Loans	939	1,151
Residential Real Estate Construction [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	3,388	2,954
Total Loans	3,388	2,954
Consumer Home Equity and Lines of Credit [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	17,032	22,204
Total Loans	17,032	22,348
Nonaccrual Loans	78	136
Consumer Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	128	361
Total Loans	128	361
Loans Past Due 30-89 Days [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	375	1,079
Loans Past Due 30-89 Days [Member] \| Commercial Real Estate [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	0	241
Loans Past Due 30-89 Days [Member] \| Commercial Other [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	33	33
Loans Past Due 30-89 Days [Member] \| Residential Real Estate First Mortgages [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	342	684
Loans Past Due 30-89 Days [Member] \| Consumer Home Equity and Lines of Credit [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	0	121
Loans Past Due 90+ Days [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	0	160
Loans Past Due 90+ Days [Member] \| Residential Real Estate First Mortgages [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	0	137
Loans Past Due 90+ Days [Member] \| Consumer Home Equity and Lines of Credit [Member]
Loans, Notes and Certificates, and Loan Servicing Rights [Line Items]
Past Due / Current Loans	$ 0	$ 23

Loans and leases receivable, ratio of nonperforming loans to all assets.

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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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