Pension Plan (Details) - Components of net periodic pension cost - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Pension Plan (Details) - Components of net periodic pension cost [Line Items]
Interest cost	$ 64,000	$ 96,000	$ 127,000	$ 193,000
Expected return on plan assets	(210,000)	(204,000)	(420,000)	(407,000)
Amortization of net actuarial loss	80,000	71,000	160,000	141,000
Net periodic pension (benefit) expense	$ (66,000)	$ (37,000)	$ (133,000)	$ (73,000)