Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Stock Options, Stock Purchase Plan and Warrants - Roll Forward of Non-Vested Stock Options Activity (Detail)

v3.6.0.2
Stock Options, Stock Purchase Plan and Warrants - Roll Forward of Non-Vested Stock Options Activity (Detail) - $ / shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]      
Number of Options, Non-vested, Beginning balance 2,718,221    
Number of Options, Granted 2,617,526 1,819,000 760,500
Number of Options, Vested (1,101,472)    
Number of Options, Forfeited (225,797)    
Number of Options, Non-vested, Ending balance 4,008,478 2,718,221  
Weighted average grant date fair value, Non-vested, Beginning balance $ 2.22    
Weighted average grant date fair value, Granted 2.23    
Weighted average grant date fair value, Vested 2.08    
Weighted average grant date fair value, Forfeited 1.48    
Weighted average grant date fair value, Non-vested, Ending balance $ 2.09 $ 2.22