Pension Plan (Details) - Components of net periodic pension cost - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Pension Plan (Details) - Components of net periodic pension cost [Line Items]
Interest cost	$ 64,000	$ 96,000	$ 190,000	$ 289,000
Expected return on plan assets	(210,000)	(203,000)	(630,000)	(610,000)
Amortization of net actuarial loss	80,000	70,000	240,000	211,000
Net periodic pension (benefit) expense	$ (66,000)	$ (37,000)	$ (200,000)	$ (110,000)