Pension Plan (Details) - Components of net periodic pension cost - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Pension Plan (Details) - Components of net periodic pension cost [Line Items]
Interest cost	$ 125	$ 113
Expected return on plan assets	(172)	(203)
Amortization of net actuarial loss	65	56
Net periodic pension expense (benefit)	$ 18	$ (34)