Retirement Plans (Details) - Defined Benefit Plan [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 437	$ 396	$ 873	$ 796
Interest cost	214	251	426	507
Expected return on plan assets	(185)	(204)	(369)	(413)
Recognized actuarial loss	69	15	138	31
Total defined benefit expense	$ 535	$ 458	$ 1,068	$ 921