Net Loss per Share Attributable to Common Stock - Summary of Anti-dilutive Stock Equivalents (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	11,944,010	12,592,084
Effect on basic earnings per share, dilutive convertible securities	$ 0
Stock options outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	7,028,719	8,713,162
Restricted stock units outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	4,681,875	3,588,275
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	233,416	290,647