Quarterly report pursuant to Section 13 or 15(d)

Net Loss Per Share Attributable to Common Stockholders - Summary of Potentially Dilutive Common Shares were Excluded from Calculation of Diluted Net Loss Per Share (Details)

v3.19.2
Net Loss Per Share Attributable to Common Stockholders - Summary of Potentially Dilutive Common Shares were Excluded from Calculation 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]    
Total dilutive common shares excluded from calculation of diluted net loss per share 2,517,518 14,631,715
Convertible Preferred Stock    
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Total dilutive common shares excluded from calculation of diluted net loss per share   11,906,783
Shares Subject to Options to Purchase Common Stock    
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Total dilutive common shares excluded from calculation of diluted net loss per share 1,261,946 1,088,221
Shares Subject to Warrants to Purchase Convertible Preferred Stock    
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Total dilutive common shares excluded from calculation of diluted net loss per share   472,947
Shares Subject to Warrants to Purchase Common Stock    
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Total dilutive common shares excluded from calculation of diluted net loss per share 156,294  
Shares Subject to Term Debt Optional Conversion into Convertible Preferred Stock    
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Total dilutive common shares excluded from calculation of diluted net loss per share   1,163,764
Shares Subject to Term Debt Optional Conversion into Common Stock    
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]    
Total dilutive common shares excluded from calculation of diluted net loss per share 1,099,278