Retirement Plans (Details) - Defined Benefit Plan [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 435	$ 400	$ 1,308	$ 1,196
Interest cost	212	256	638	763
Expected return on plan assets	(184)	(209)	(553)	(622)
Recognized actuarial loss	69	16	207	47
Total defined benefit expense	$ 532	$ 463	$ 1,600	$ 1,384