Net Loss Per Share - Summary of Anti Dilutive Loss Attributable to Common Stockholders (Details) - shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive common stock equivalents excluded from the calculation of diluted net loss per share (in shares)	4,881,815	23,705,028
Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive common stock equivalents excluded from the calculation of diluted net loss per share (in shares)		20,454,489
Outstanding Stock Options and Employee Stock Purchase Plan
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive common stock equivalents excluded from the calculation of diluted net loss per share (in shares)	4,684,111	3,163,039
Outstanding Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive common stock equivalents excluded from the calculation of diluted net loss per share (in shares)	197,704
Preferred stock warrant
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive common stock equivalents excluded from the calculation of diluted net loss per share (in shares)		87,500