Fair Value - Estimated Fair Values (Details) - USD ($)	Jun. 30, 2024	Dec. 31, 2023
Assets
Investment securities available for sale, at fair value	$ 19,095,000	$ 20,171,000
Investment securities held to maturity	535,799,000	568,128,000
Loans held for sale	312,000
Liabilities
Advances from Federal Reserve Bank	50,000,000	50,000,000
Carrying Amount
Assets
Cash and cash equivalents	82,782,000	126,659,000
Investment securities available for sale, at fair value	19,095,000	20,171,000
Investment securities held to maturity	666,103,000	685,728,000
Loans held for sale	312,000
Loans receivable, net	1,301,057,000	1,303,431,000
FHLB stock	12,007,000	12,192,000
FRB stock	3,185,000	3,180,000
Accrued interest receivable	6,039,000	6,105,000
Liabilities
Deposits	1,572,751,000	1,636,604,000
Advances from the Federal Home Loan Bank	237,000,000	242,000,000
Advances from Federal Reserve Bank	50,000,000	50,000,000
Securities sold under agreements to repurchase	10,000,000	10,000,000
Accrued interest payable	1,625,000	1,183,000
Estimated Fair Value
Assets
Cash and cash equivalents	82,782,000	126,659,000
Investment securities available for sale, at fair value	19,095,000	20,171,000
Investment securities held to maturity	535,799,000	568,128,000
Loans held for sale	319,000
Loans receivable, net	1,082,564,000	1,120,704,000
FHLB stock	12,007,000	12,192,000
FRB stock	3,185,000	3,180,000
Accrued interest receivable	6,039,000	6,105,000
Liabilities
Deposits	1,569,681,000	1,633,164,000
Advances from the Federal Home Loan Bank	233,922,000	238,380,000
Advances from Federal Reserve Bank	49,850,000	50,049,000
Securities sold under agreements to repurchase	9,837,000	9,700,000
Accrued interest payable	1,625,000	1,183,000
Estimated Fair Value | Level 1
Assets
Cash and cash equivalents	82,782,000	126,659,000
Accrued interest receivable	61,000	79,000
Estimated Fair Value | Level 2
Assets
Investment securities available for sale, at fair value	19,095,000	20,171,000
Investment securities held to maturity	535,799,000	568,128,000
Loans held for sale	319,000
FHLB stock	12,007,000	12,192,000
FRB stock	3,185,000	3,180,000
Accrued interest receivable	1,396,000	1,441,000
Liabilities
Deposits	1,040,743,000	1,104,171,000
Advances from the Federal Home Loan Bank	233,922,000	238,380,000
Advances from Federal Reserve Bank	49,850,000	50,049,000
Securities sold under agreements to repurchase	9,837,000	9,700,000
Accrued interest payable	1,105,000	157,000
Estimated Fair Value | Level 3
Assets
Loans receivable, net	1,082,564,000	1,120,704,000
Accrued interest receivable	4,582,000	4,585,000
Liabilities
Deposits	528,938,000	528,993,000
Accrued interest payable	$ 520,000	$ 1,026,000