Borrowed Funds (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020
Disclosure of Repurchase Agreements [Abstract]
Amount of line of credit with correspondent banks	$ 76,000,000
Credit facility with Federal Reserve Bank	139,000,000
Line of credit with correspondent banks and credit facility with Federal Reserve Of Boston	$ 0
Federal Home Loan Bank, Advances, Maturities Summary [Abstract]
Interest rate, due in year two	0.00%	0.00%
Interest rate, due in year three	0.00%	0.00%
Interest rate, due in year four		0.00%
Interest rate, due in year five and thereafter	0.00%	0.00%
Due in twelve months maturity	$ 0	$ 137,600,000
Due in year two maturity	0	0
Due in year three maturity	90,000	0
Due in year four maturity	55,000,000	98,000
Due in year five maturity		55,000,000
Due thereafter	0	0
Total	55,090,000	192,698,000
Repurchase agreements for municipal and commercial customers	81,252,000	69,340,000
Total	$ 136,342,000	$ 262,038,000	$ 233,201,000	$ 228,648,000	$ 229,648,000	$ 283,787,000	$ 278,805,000	$ 248,040,000
Minimum
Disclosure of Repurchase Agreements [Abstract]
Range of repurchase agreements' maturity dates (days)	1 day
Federal Home Loan Bank, Advances, Maturities Summary [Abstract]
Interest rate, due in next twelve months	0.00%	0.00%
Interest rate, due in year four	1.35%
Interest rate, due in year five		1.35%
Interest rate, Repurchase agreements for municipal and commercial customers	0.05%	0.10%
Maximum
Disclosure of Repurchase Agreements [Abstract]
Range of repurchase agreements' maturity dates (days)	3 days
Federal Home Loan Bank, Advances, Maturities Summary [Abstract]
Interest rate, due in next twelve months		1.55%
Interest rate, due in year four	1.40%
Interest rate, due in year five		1.40%
Interest rate, Repurchase agreements for municipal and commercial customers	2.00%	2.00%