Quarterly report pursuant to Section 13 or 15(d)

Stockholders' equity - Underwritten public offering and Registered direct offering (Details)

v3.20.1
Stockholders' equity - Underwritten public offering and Registered direct offering (Details) - American Depository Shares (ADSs)
$ in Millions
Jan. 24, 2020
USD ($)
shares
Stockholders' equity  
Issuance of common stock (in shares) 21,000,000
Net proceeds | $ $ 90
Over-Allotment Option  
Stockholders' equity  
Issuance of common stock (in shares) 3,150,000