Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Detail)

v3.7.0.1
Subsequent Events - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
1 Months Ended
Jul. 24, 2017
Feb. 07, 2017
Jul. 31, 2017
Jun. 30, 2017
Dec. 31, 2016
Subsequent Event [Line Items]          
Proceeds from sale of common stock       28,752,451 23,447,003
Common sock offering price   $ 1.93      
Proceeds from sale of common stock   $ 9.2      
Subsequent Event [Member]          
Subsequent Event [Line Items]          
Proceeds from sale of common stock 14,950,000        
Common sock offering price $ 6.50        
Proceeds from sale of common stock $ 91.1        
Subsequent Event [Member] | Jones Trading Institutional Services LLC [Member]          
Subsequent Event [Line Items]          
ATM facility terminated     $ 25.0