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 - Status of Our Stock Options and Stock Awards (Detail)

v3.6.0.2
Stock Options, Stock Purchase Plan and Warrants - Status of Our Stock Options and Stock Awards (Detail) - $ / shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]      
Stock options, beginning balance 5,326,505 4,012,096 5,725,298
Stock options, granted 2,617,526 1,819,000 760,500
Stock options, exercised (2,483,519) (492,091) (2,387,327)
Stock options, cancelled (324,402) (12,500) (86,375)
Stock options, ending balance 5,136,110 5,326,505 4,012,096
Stock options, exercisable, ending balance 1,127,632    
Weighted average exercise price, beginning balance $ 3.07 $ 2.04 $ 1.22
Weighted average exercise price, granted 7.14 4.90 4.21
Weighted average exercise price, exercised 1.69 1.45 0.76
Weighted average exercise price, cancelled 3.99 3.19 2.39
Weighted average exercise price, ending balance 5.76 $ 3.07 $ 2.04
Weighted average exercise price, exercisable, ending balance $ 3.89