Goodwill and Intagible Assets (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Goodwill [Line Items]
Goodwill	$ 32,848		$ 32,848		$ 33,872
Intangible Assets, Gross (Excluding Goodwill)	11,637		11,637		15,120
Amortization expense	$ (958)	$ (1,096)	(3,101)	$ (3,266)
Finite-lived Intangible Assets Acquired			22		$ 100
Finite-Lived Intangible Assets, Translation Adjustments			$ (404)