Employee Benefit Plans - Estimated Amount that will be Recognized From Accumulated Other Comprehensive Income (Loss) into Net Periodic Benefit Cost (Details) - Post-employment benefits $ in Thousands	Dec. 31, 2017 USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial net loss	$ (92)
Net prior service credits	37
Net amount recognized	$ (55)