Employee Benefits - Components of Net Periodic Pension Cost and Other Changes in Plan Assets and Benefit (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Components of Net Periodic Pension Cost
Interest cost on projected benefit obligation	$ 905	$ 989	$ 2,686	$ 2,967
Expected return on plan assets	(970)	(1,181)	(2,913)	(3,541)
Net amortization	411	395	1,180	1,184
Settlement Charge	671	0	671	0
Net Periodic Pension Expense	$ 1,017	$ 203	$ 1,624	$ 610