Securities and loans pledged to secure public and trust deposits, securities sold under agreements to repurchase, FHLBB advances and credit facilities available - Guarantee Type, Other [Member] - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Guarantor Obligations [Line Items]
Securities available-for-sale (at fair value)	$ 61,542	$ 52,845
Loans receivable (at book value)	427,828	434,329
Total pledged assets	$ 489,370	$ 487,174