Pension and Postretirement Benefits - Composition of Net Periodic Pension Plan and Postretirement Plan Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 116	$ 111	$ 232	$ 221
Expected return on plan assets	(267)	(287)	(534)	(573)
Amortization of net losses		25		50
Net periodic benefit plan (benefit) cost	(151)	(151)	(302)	(302)
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	2	2	5	6
Amortization of prior service credits	(1)	(1)	(2)	(2)
Amortization of net losses	2	2	4	4
Net periodic benefit plan (benefit) cost	$ 3	$ 3	$ 7	$ 8