Pension and Other Postretirement Benefits - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Pension Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 180	$ 316
Interest cost	1,360	1,090
Expected return on plan assets	(2,084)	(2,082)
Actuarial loss (gain) amortization	257	855
Prior service cost (income) amortization	2	2
Total net periodic benefit (income) cost	(285)	181
Postretirement Benefits [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	(8)	1
Interest cost	9	11
Expected return on plan assets	0	0
Actuarial loss (gain) amortization	(24)	0
Prior service cost (income) amortization	1	0
Total net periodic benefit (income) cost	$ (22)	$ 12