Annual report pursuant to Section 13 and 15(d)

Common Stock - Summary of Stock Options Activity (Detail)

v3.6.0.2
Common Stock - Summary of 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 Optioned Common Shares, Beginning Balance 1,479,221 1,283,419 1,007,491
Number of Optioned Common Shares, Granted 1,635,250 502,047 382,097
Number of Optioned Common Shares, Expired (994,059) (247,766) (12,169)
Number of Optioned Common Shares, Exercised 0 (5,359) (10,000)
Number of Optioned Common Shares, Forfeited (741,607) (53,120) (84,000)
Number of Optioned Common Shares, Ending Balance 1,378,805 1,479,221 1,283,419
Weighted Average Exercise Price, Beginning Balance $ 8.78 $ 10.55 $ 11.39
Weighted Average Exercise Price, Granted 0.86 1.91 8.97
Weighted Average Exercise Price, Expired 1.00 2.96 18.93
Weighted Average Exercise Price, Exercised   2.69 3.00
Weighted Average Exercise Price, Forfeited 1.96 14.37 12.14
Weighted Average Exercise Price, Ending Balance $ 8.62 $ 8.78 $ 10.55