Net Loss Per Share - Computation of Basic and Diluted Net Loss per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Numerator:
Net loss attributable to common stockholders	$ (28,246)	$ (70,852)	$ (1,201)
Deemed dividend to convertible preferred stockholders	(24,890)
Net loss available to common stockholders	$ (53,136)	$ (70,852)	$ (1,201)
Denominator:
Weighted average shares used to compute net loss per share available to common stockholders, basic and diluted	55,091	22,795	9,780
Basic and diluted	$ (0.96)	$ (3.11)	$ (0.12)