Defined Benefit Plans - Net Periodic Pension Costs (Details) - Pension Plans, Defined Benefit [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service costs	$ 320	$ 260
Interest costs	240	270
Expected return on plan assets	(370)	(350)
Amortization of net (gain)/loss	220	140
Net periodic benefit cost	$ 410	$ 320