Basic and Diluted Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Ordinary Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net loss attributable to ordinary shares as reported	$ (22,168)	$ (33,628)	$ (40,612)	$ (35,437)	$ (32,928)	$ (26,023)	$ (29,357)	$ (23,273)	$ (131,845)	$ (111,581)	$ (80,682)
Shares used in computing net loss per ordinary share, basic and diluted	86,760,316	85,774,874	85,274,683	84,397,164	83,607,037	12,431,586	12,427,442	13,140,321	85,558,448	30,401,603	12,490,017
Net loss per ordinary share, basic and diluted	$ (0.26)	$ (0.39)	$ (0.48)	$ (0.42)	$ (0.39)	$ (2.09)	$ (2.36)	$ (1.77)	$ (1.54)	$ (3.67)	$ (6.46)