Pension and Other Postretirement Benefit Plans (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Directors' Plan [Member]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		$ 300,000
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 108,000
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year		$ 300,000
Defined Benefit Plan, Plan Assets, Contributions by Employer	97,000
Retirement Plan [Member] | Savings Bank [Member]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 0