Supplemental Compensation Plans, Components of Net Periodic Benefit Cost and Additional Information (Details) - Pension Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Salary Continuation Plan and SERP [Member]
Components of net periodic benefit cost [Abstract]
Service cost	$ 312	$ 256
Interest cost	168	180
Amortization of prior service cost	2	2
Recognized actuarial loss (gain)	205	115
Net periodic benefit cost	687	553
Additional Information [Abstract]
Minimum benefit obligation at year end	6,581	7,127	$ 5,871
(Decrease) increase in minimum liability included in other comprehensive income (loss)	(961)	974
Directors' Retirement Plan [Member]
Components of net periodic benefit cost [Abstract]
Service cost	0	0
Interest cost	10	19
Recognized actuarial loss (gain)	0	0
Net periodic benefit cost	10	19
Additional Information [Abstract]
Minimum benefit obligation at year end	710	831	$ 820
(Decrease) increase in minimum liability included in other comprehensive income (loss)	$ (56)	$ 52