Financial Income and Expenses - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Financial income (expense)	$ 546	$ 4,541	$ (11,390)
Foreign exchange (loss) gain	$ 506	(5,971)	$ 10,096
IPO
Class of Stock [Line Items]
Gain on sale of stock		2,100
Proceeds from IPO		$ 70,000