Securities and loans pledged to secure public and trust deposits, securities sold under agreements to repurchase, FHLBB advances and credit facilities available (Details) - Guarantee Type, Other [Member] - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Guarantor Obligations [Line Items]
Securities available-for-sale (at fair value)	$ 75,737	$ 54,581
Loans receivable (at book value)	378,845	420,415
Total pledged assets	$ 454,582	$ 474,996