Loans and Allowance for Loan Losses - Summary of Activity in the Allowance for Loan Losses by Loan Category (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	$ 6,289	$ 6,784
Provision (credit) for loan losses	71	(213)
Loans charged-off	(4)	(10)
Recoveries	1	2
Ending balance	6,357	6,563
Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	3,451	3,402
Provision (credit) for loan losses	(49)	(12)
Ending balance	3,402	3,390
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	499	416
Provision (credit) for loan losses	(23)	(15)
Ending balance	476	401
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	87	127
Provision (credit) for loan losses	(7)	(12)
Loans charged-off	(4)	(10)
Ending balance	76	105
One-to-Four Family [Member] \| Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	1,093	1,646
Provision (credit) for loan losses	142	(126)
Recoveries	1	2
Ending balance	1,236	1,522
Second Mortgages and HELOC [Member] \| Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	462	442
Provision (credit) for loan losses	(11)	(17)
Ending balance	451	425
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	697	751
Provision (credit) for loan losses	19	(31)
Ending balance	$ 716	$ 720

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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