Loans, Allowance for Credit Losses and Credit Quality - Schedule of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2024		Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	[1]	Jun. 30, 2023	Dec. 31, 2022
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 1,124,491			$ 1,048,606
Net deferred loan fees	(480)			(226)
Allowance for credit losses	(9,068)	[1]	$ (9,025)	(8,591)	$ (8,292)		$ (8,470)	$ (7,200)
Total loans, net	$ 1,114,943			$ 1,039,789
Total loans, gross percent	100.00%			100.00%
Real Estate Loans | Home Equity Lines of Credit and Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 39,413			$ 33,357
Allowance for credit losses	$ (382)	[1]	(363)	$ (321)	(207)		(203)	(194)
Total loans, gross percent	3.50%			3.20%
Real Estate Loans | One-to Four Family Residential
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 419,373			$ 410,131
Total loans, gross percent	37.30%			39.10%
Real Estate Loans | Multi Family
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 326,975			$ 287,361
Allowance for credit losses	$ (1,357)	[1]	(1,304)	$ (1,190)	(2,229)		(2,150)	(1,839)
Total loans, gross percent	29.10%			27.40%
Real Estate Loans | Commercial Real Estate Loans
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 222,680			$ 196,365
Allowance for credit losses	$ (1,835)	[1]	(1,740)	$ (1,636)	(2,194)		(2,348)	(1,797)
Total loans, gross percent	19.80%			18.70%
Real Estate Loans | Construction
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 101,401			$ 112,000
Allowance for credit losses	$ (1,603)	[1]	(1,814)	$ (1,757)	(1,444)		(1,570)	(1,286)
Total loans, gross percent	9.00%			10.70%
Other Loans | Commercial
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 14,508			$ 9,219
Allowance for credit losses	$ (205)	[1]	(199)	$ (131)	(197)		(218)	(60)
Total loans, gross percent	1.30%			0.90%
Other Loans | Consumer
Accounts Notes And Loans Receivable [Line Items]
Total loans, gross	$ 141			$ 173
Allowance for credit losses	$ (1)	[1]	$ (1)	$ (1)	$ (1)		$ (1)	$ (1)
Total loans, gross percent	0.00%			0.00%

[1] (1) Balances of accrued interest receivable excluded from amortized cost and the calculation of allowance for credit losses amounted to $3.5 million and $2.9 million as of September 30, 2024 and September 30, 2023.