Other Income (Expense), Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Income and Expenses [Abstract]
Foreign exchange losses	$ (355)	$ (770)	$ (444)
Other expense	(181)	(202)	(406)
Other income (expense), net	$ (536)	$ (972)	$ (850)