Loans, Allowance for Loan Losses and Credit Quality - Schedule of Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 539,497	$ 521,800
Net deferred loan fees	(369)	(433)
Allowance for losses	(4,357)	(4,236)	$ (3,966)	$ (3,876)
Total loans, net	534,771	517,131
Commercial Loans
Accounts Notes And Loans Receivable [Line Items]
Allowance for losses	(50)	(60)	(116)	(103)
Consumer
Accounts Notes And Loans Receivable [Line Items]
Allowance for losses	(1)	(2)	(1)	(4)
Real Estate Loans | Home Equity Lines of Credit
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	26,626	26,050
Allowance for losses	$ (191)	$ (185)	(180)	(208)
Total loans, gross percent	4.90%	5.00%
Real Estate Loans | One-to Four Family Residential
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 268,214	$ 259,673
Total loans, gross percent	49.70%	49.80%
Real Estate Loans | Multi Family
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 65,258	$ 59,517
Allowance for losses	$ (463)	$ (417)	(322)	(266)
Total loans, gross percent	12.10%	11.40%
Real Estate Loans | Commercial Real Estate Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 103,561	$ 99,953
Allowance for losses	$ (1,150)	$ (1,099)	(1,080)	(1,175)
Total loans, gross percent	19.20%	19.20%
Real Estate Loans | Construction
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 71,302	$ 70,668
Allowance for losses	$ (871)	$ (855)	$ (699)	$ (802)
Total loans, gross percent	13.20%	13.50%
Other Loans | Commercial Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 4,181	$ 5,439
Total loans, gross percent	0.80%	1.00%
Other Loans | Consumer
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 355	$ 500
Total loans, gross percent	0.10%	0.10%