Quarterly report pursuant to Section 13 or 15(d)

Summary of Warrant Activity (Detail)

v3.7.0.1
Summary of Warrant Activity (Detail) - Warrants - $ / shares
 6 Months Ended
Jun. 30, 2017
Dec. 31, 2016
Shares    
Warrants outstanding 15,332,131 11,406,260
Granted 3,925,871  
Warrants exercisable at June 30, 2017 11,271,260  
Weighted Average Exercise Price    
Beginning Balance $ 3.17 $ 3.64
Granted or Issued 1.80  
Warrants exercisable at June 30, 2017 $ 3.64