Employee Benefit Plan (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Employee Benefit Plan
Service cost	$ 216	$ 202,000	$ 648,000	$ 606,000
Interest cost	95,000	105,000	285,000	314,000
Expected return on plan assets	(198,000)	(18,000)	(594,000)	(55,000)
Amortization of prior service cost	0	(3,000)	0	(9,000)
Amortization of net loss	72,000	55,000	216,000	166,000
Net periodic pension cost	$ 185,000	$ 341,000	$ 555,000	$ 1,022,000