Loans Receivable and Allowance for Credit Losses (Narrative) (Details)	3 Months Ended
	Mar. 31, 2024 USD ($) item property	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Real Estate Acquired Through Foreclosure	$ 97,000		$ 97,000
Financing Receivable, before Allowance for Credit Loss	$ 1,621,680,000		1,603,877,000
Number of loan modifications to borrowers experiencing financial difficulty | item	3
Charge offs	$ 494,000	$ 364,000
Allowance for loan losses	18,020,000	19,445,000	18,968,000
(Release of) Provision for credit losses	(625,000)	300,000
Residential Rentals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge offs	0
Commercial Rentals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge offs	$ 0
Residential Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number Of Properties Under Foreclosure Proceedings | property	6
Mortgage Loans in Process of Foreclosure, Amount	$ 285,000
Financing Receivable, before Allowance for Credit Loss	313,531,000		316,546,000
Allowance for loan losses	1,197,000	1,359,000	1,351,000
(Release of) Provision for credit losses	(196,000)	65,000
Residential Real Estate Loans [Member] | Residential Rentals [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 113,474,000
Concentration Risk, Percentage	7.00%
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 691,755,000		675,156,000
Charge offs		112,000
Allowance for loan losses	9,831,000	13,725,000	$ 11,871,000
(Release of) Provision for credit losses	(2,142,000)	$ 11,000
Commercial Real Estate Loans [Member] | Commercial Rentals [Member] | Loans Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 148,899,000
Concentration Risk, Percentage	9.18%
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Annual Loan Review threshold, amount	$ 1,500,000
Adoption Impact [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses				$ 2,466,000
Adoption Impact [Member] | Residential Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses				(1,545,000)
Adoption Impact [Member] | Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses				$ 5,527,000