Employee Benefits - Components of Net Periodic Pension Cost and Other Changes in Plan Assets and Benefit (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Components of Net Periodic Pension Cost
Interest cost on projected benefit obligation	$ 891	$ 989
Expected return on plan assets	(972)	(1,180)
Net amortization	384	394
Net Periodic Pension Expense	$ 303	$ 203