Pension Plan (Details) - Components of net periodic pension cost - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Pension Plan (Details) - Components of net periodic pension cost [Line Items]
Interest cost	$ 126	$ 114	$ 251	$ 227
Expected return on plan assets	(173)	(203)	(345)	(406)
Amortization of net actuarial loss	66	56	131	112
Net periodic pension expense (benefit)	$ 19	$ (33)	$ 37	$ (67)