Pension Plan (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Retirement Benefits [Abstract]
Service cost	$ 248	$ 179	$ 496	$ 358
Interest cost on projected benefit obligation	451	639	902	1,278
Expected return on plan assets	(1,289)	(1,255)	(2,578)	(2,510)
Net amortization and deferral	832	705	1,664	1,410
Net periodic pension cost	$ 242	268	$ 484	536
Defined Benefit Plan, Non-service cost		$ 100		$ 200