Pension Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Retirement Benefits [Abstract]
Net service cost	$ (1,084)	$ (859)	$ (3,300)	$ (2,484)
Interest cost	(163)	(259)	(495)	(745)
Expected return on plan assets	105	161	322	463
Administrative charges	(71)	(73)	(214)	(203)
Net periodic pension cost	$ (1,213)	$ (1,030)	$ (3,687)	$ (2,969)