Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Pension Plans, Defined Benefit
Components of net periodic benefit costs:
Interest cost	$ 109	$ 105
Expected return on plan assets	(195)	(147)
Amortization of net loss	19	28
Net periodic benefit/cost	(67)	(14)
Other Postretirement Benefit Plans, Defined Benefit
Components of net periodic benefit costs:
Interest cost	1	1
Amortization of net loss	(2)	(2)
Net periodic benefit/cost	$ (1)	$ (1)
Other Postretirement Benefit Plans, Defined Benefit | Employees Hired before January 1, 2003
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Benefit based on highest average salary for number of consecutive years	5 years
Number of years for consecutive years calculation	10 years
Other Postretirement Benefit Plans, Defined Benefit | Employees Hired on or after January 1, 2003
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Percent of annual salary to calculate benefit	2.00%