Pension Plan (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Retirement Benefits [Abstract]
Service cost	$ 179	$ 253	$ 537	$ 759
Interest cost on projected benefit obligation	639	782	1,917	2,346
Expected return on plan assets	(1,255)	(1,181)	(3,765)	(3,543)
Net amortization and deferral	705	720	2,115	2,160
Net periodic pension cost	268	574	804	1,722
Defined Benefit Plan, Non-service cost	$ 100	$ 300	$ 300	$ 1,000