Quarterly report pursuant to Section 13 or 15(d)

Net Loss Per Share - Anti-dilutive Outstanding Shares of Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share (Details)

v3.19.1
Net Loss Per Share - Anti-dilutive Outstanding Shares of Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share (Details) - shares
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Anti-dilutive securities excluded from computation of diluted net loss per share 2,816,731 13,870,394
Redeemable Convertible Preferred Stock on an if Converted Basis    
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Anti-dilutive securities excluded from computation of diluted net loss per share   12,263,126
Stock Options to Purchase Common Stock    
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Anti-dilutive securities excluded from computation of diluted net loss per share 2,755,466 1,354,965
Common stock subject to future vesting [Member]    
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Anti-dilutive securities excluded from computation of diluted net loss per share 61,265 252,303