Quarterly report pursuant to Section 13 or 15(d)

Warrants - Additional Information (Detail)

v3.19.2
Warrants - Additional Information (Detail)
$ / shares in Units, $ in Millions
Mar. 25, 2019
USD ($)
$ / shares
shares
Underwritten Public Offering [Member]  
Class of Warrant or Right [Line Items]  
Proceeds from public offering | $ $ 12.5
Share price per unit | $ / shares $ 0.75
Warrants exercise price per share | $ / shares $ 0.75
Underwritten Public Offering [Member] | Common Stock [Member]  
Class of Warrant or Right [Line Items]  
Number of common stock issued in offering 16,666,668
Underwritten Public Offering [Member] | Short-term Warrants [Member]  
Class of Warrant or Right [Line Items]  
Warrants exercise price per share | $ / shares $ 0.75
Exercisable term of warrants 18 months
Trading period 21 days
Underwritten Public Offering [Member] | Short-term Warrants [Member] | Maximum [Member]  
Class of Warrant or Right [Line Items]  
Shares of common stock callable by warrants issued 8,333,334
Underwritten Public Offering [Member] | Long-term Warrants [Member]  
Class of Warrant or Right [Line Items]  
Warrants exercise price per share | $ / shares $ 0.90
Term of warrants 5 years
Underwritten Public Offering [Member] | Long-term Warrants [Member] | Maximum [Member]  
Class of Warrant or Right [Line Items]  
Shares of common stock callable by warrants issued 8,333,334
Underwriter [Member] | Common Stock [Member] | Maximum [Member]  
Class of Warrant or Right [Line Items]  
Number of shares of stock available for purchase 2,500,000
Underwriter [Member] | Short-term Warrants [Member]  
Class of Warrant or Right [Line Items]  
Number of warrants available for purchase 1,250,000
Underwriter [Member] | Long-term Warrants [Member]  
Class of Warrant or Right [Line Items]  
Number of warrants available for purchase 1,250,000
Underwriter [Member] | Short-term Warrants [Member]  
Class of Warrant or Right [Line Items]  
Number of warrants purchased in period 1,250,000
Underwriter [Member] | Long-term Warrants [Member]  
Class of Warrant or Right [Line Items]  
Number of warrants purchased in period 1,250,000