Net Loss per Share Attributable to Common Stock - Summary of Anti-dilutive Stock Equivalents (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	12,873,233	12,348,642	12,873,233	12,348,642
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)	6,493,269	8,411,868	6,493,269	8,411,868
Restricted stock units outstanding(1)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	4,339,964	3,936,774	4,339,964	3,936,774
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	0	0	0	0
Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	2,040,000	0	2,040,000	0