Loans, Allowance for Credit Losses and Credit Quality - Schedule of Information Regarding Allowance for Loan Losses (Details) - USD ($)		3 Months Ended				9 Months Ended				12 Months Ended
		Sep. 30, 2024		Sep. 30, 2023		Sep. 30, 2024		Sep. 30, 2023		Dec. 31, 2023
Allowance for loan losses
Beginning balance		$ 9,025,000		$ 8,470,000		$ 8,591,000		$ 7,200,000		$ 7,200,000
Charge-offs		0		(1,000)		(3,000)		(1,000)
Recoveries		0		1,000		0		1,000
Provision (benefit)		43,000		(178,000)		480,000		910,000
Ending balance		9,068,000	[1]	8,292,000	[1]	9,068,000	[1]	8,292,000	[1]	8,591,000
Cumulative effect accounting adjustment | ASU 2016-13
Allowance for loan losses
Beginning balance	[2]							182,000		182,000
Ending balance				182,000				182,000
Unallocated
Allowance for loan losses
Beginning balance								320,000		320,000
Charge-offs								0
Recoveries								0
Provision (benefit)								0
Ending balance	[1]			0				0
Unallocated | Cumulative effect accounting adjustment | ASU 2016-13
Allowance for loan losses
Beginning balance	[2]							(320,000)		(320,000)
Real Estate | Home Equity Lines of Credit and Loans
Allowance for loan losses
Beginning balance		363,000		203,000		321,000		194,000		194,000
Charge-offs		0		0		0		0		0
Recoveries		0		0		0		0
Provision (benefit)		19,000		4,000		61,000		33,000
Ending balance		382,000	[1]	207,000	[1]	382,000	[1]	207,000	[1]	321,000
Real Estate | Home Equity Lines of Credit and Loans | Cumulative effect accounting adjustment | ASU 2016-13
Allowance for loan losses
Beginning balance	[2]							(20,000)		(20,000)
Real Estate | One- to Four-Family Residential
Allowance for loan losses
Beginning balance		3,604,000		1,980,000		3,555,000		1,703,000		1,703,000
Charge-offs		0		0		0		0		0
Recoveries		0		0		0		0
Provision (benefit)		81,000		40,000		130,000		187,000
Ending balance		3,685,000	[1]	2,020,000	[1]	3,685,000	[1]	2,020,000	[1]	3,555,000
Real Estate | One- to Four-Family Residential | Cumulative effect accounting adjustment | ASU 2016-13
Allowance for loan losses
Beginning balance	[2]							130,000		130,000
Real Estate | Multi Family
Allowance for loan losses
Beginning balance		1,304,000		2,150,000		1,190,000		1,839,000		1,839,000
Charge-offs		0		0		0		0		0
Recoveries		0		0		0		0
Provision (benefit)		53,000		79,000		167,000		313,000
Ending balance		1,357,000	[1]	2,229,000	[1]	1,357,000	[1]	2,229,000	[1]	1,190,000
Real Estate | Multi Family | Cumulative effect accounting adjustment | ASU 2016-13
Allowance for loan losses
Beginning balance	[2]							77,000		77,000
Real Estate | Commercial
Allowance for loan losses
Beginning balance		1,740,000		2,348,000		1,636,000		1,797,000		1,797,000
Charge-offs		0		0		0		0		0
Recoveries		0		0		0		0
Provision (benefit)		95,000		(154,000)		199,000		252,000
Ending balance		1,835,000	[1]	2,194,000	[1]	1,835,000	[1]	2,194,000	[1]	1,636,000
Real Estate | Commercial | Cumulative effect accounting adjustment | ASU 2016-13
Allowance for loan losses
Beginning balance	[2]							145,000		145,000
Real Estate | Construction
Allowance for loan losses
Beginning balance		1,814,000		1,570,000		1,757,000		1,286,000		1,286,000
Charge-offs		0		0		0		0		0
Recoveries		0		0		0		0
Provision (benefit)		(211,000)		(126,000)		(154,000)		22,000
Ending balance		1,603,000	[1]	1,444,000	[1]	1,603,000	[1]	1,444,000	[1]	1,757,000
Real Estate | Construction | Cumulative effect accounting adjustment | ASU 2016-13
Allowance for loan losses
Beginning balance	[2]							136,000		136,000
Other Loans | Commercial
Allowance for loan losses
Beginning balance		199,000		218,000		131,000		60,000		60,000
Charge-offs		0		0		0		0		0
Recoveries		0		0		0		0
Provision (benefit)		(6,000)		(21,000)		74,000		103,000
Ending balance		205,000	[1]	197,000	[1]	205,000	[1]	197,000	[1]	131,000
Other Loans | Commercial | Cumulative effect accounting adjustment | ASU 2016-13
Allowance for loan losses
Beginning balance	[2]							34,000		34,000
Other Loans | Consumer
Allowance for loan losses
Beginning balance		1,000		1,000		1,000		1,000		1,000
Charge-offs		0		(1,000)		(3,000)		(1,000)		(2,000)
Recoveries		0		1,000		0		1,000
Provision (benefit)		0		0		3,000		0
Ending balance		$ 1,000	[1]	$ 1,000	[1]	$ 1,000	[1]	1,000	[1]	1,000
Other Loans | Consumer | Cumulative effect accounting adjustment | ASU 2016-13
Allowance for loan losses
Beginning balance	[2]							$ 0		$ 0

[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.

[2] (2) Represents an adjustment needed to reflect the cumulative day one impact pursuant to the Company's adoption of Accounting Standards Update 2016-13. The adjustment for the nine months ended September 30, 2023 represents a $182,000 increase to the allowance for credit losses attributable to the change in accounting methodology for estimating the allowance for credit losses on loans resulting from the Company's adoption of the standard.