Employee Retirement Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Components of the Company's net periodic pension cost
Service cost	$ 115	$ 116	$ 345	$ 347
Interest cost	502	615	1,508	1,845
Expected return on plan assets	(693)	(625)	(2,081)	(1,876)
Net amortization and deferral	191	156	573	469
Net periodic pension cost	$ 115	$ 262	$ 345	$ 785