Risks and Uncertainties (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Risks and Uncertainties [Abstract]
Additional borrowing capacity of Federal Home Loan Bank of Boston and the Federal Reserve Bank of Boston	$ 416,600
Outstanding borrowing capacity of Federal Home Loan Bank of Boston and the Federal Reserve Bank of Boston	$ 89,700
Securities Portfolio, Percent Of Total Assets	1.70%
Accumulated other comprehensive loss	$ 1,602	$ 1,496
Accumulated other comprehensive loss, percent	0.70%