Annual report pursuant to Section 13 and 15(d)

Public Warrant Tender Offerings - Additional Information (Detail)

v3.20.2
Public Warrant Tender Offerings - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
 1 Months Ended 2 Months Ended
Jun. 30, 2020
Jul. 31, 2019
May 31, 2020
May 31, 2019
Public Warrant Tender Offerings [Line Items]        
Common stock, par value     $ 0.001 $ 0.001
Minimum        
Public Warrant Tender Offerings [Line Items]        
Purchase price, per share $ 0.35      
Maximum        
Public Warrant Tender Offerings [Line Items]        
Purchase price, per share $ 1.35      
Public Warrant Tender Offerings [Member]        
Public Warrant Tender Offerings [Line Items]        
Common stock sold at private equity offering 16,543,539 45,375,923    
Common stock, par value   $ 0.001    
Proceeds from issuance of common shares $ 7.8 $ 11.9    
Placement agent fees and expenses   1.1    
Noncash inducement interest expense   $ 2.4    
Public Warrant Tender Offerings [Member] | Minimum        
Public Warrant Tender Offerings [Line Items]        
Purchase price, per share $ 0.21 $ 0.30    
Public Warrant Tender Offerings [Member] | Maximum        
Public Warrant Tender Offerings [Line Items]        
Purchase price, per share $ 0.95 $ 0.40