Quarterly report pursuant to Section 13 or 15(d)

Related Party Transactions - Additional Information (Details)

v3.19.1
Related Party Transactions - Additional Information (Details) - USD ($)
$ in Millions
3 Months Ended
Aug. 01, 2017
Mar. 31, 2019
Longitude Venture Partners III, L.P. | Private Placement    
Related Party Transaction [Line Items]    
Ownership percentage of merger company 15.30%  
Investments $ 20.0  
Longitude Venture Partners III, L.P. | Public Offering | Common Stock    
Related Party Transaction [Line Items]    
Ownership percentage of merger company   12.33%
Stock issued   365,000
CDK Associates, L.L.C. | Private Placement    
Related Party Transaction [Line Items]    
Ownership percentage of merger company 4.99%  
Investments $ 7.0  
CDK Associates, L.L.C. | Public Offering | Common Stock    
Related Party Transaction [Line Items]    
Ownership percentage of merger company   4.96%
Stock issued   545,454
BVF Partners L.P. | Public Offering    
Related Party Transaction [Line Items]    
Ownership percentage of merger company   7.60%
Investments   $ 15.3
Perceptive Advisors LLC | Public Offering    
Related Party Transaction [Line Items]    
Ownership percentage of merger company   5.90%
Investments   $ 11.9