Annual report pursuant to Section 13 and 15(d)

Summary of Unvested Restricted Stock Units (Detail)

v3.7.0.1
Summary of Unvested Restricted Stock Units (Detail) - Restricted Stock Units (RSUs) - $ / shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Shares      
Beginning Balance   36,868  
Granted 906,773   36,868
Vested (488,262) (36,868)  
Ending Balance 418,511   36,868
Weighted-Average Exercise Price Per Share      
Beginning Balance   $ 2.17  
Granted $ 1.06   $ 2.17
Vested 0.91 $ 2.17  
Ending Balance $ 1.23   $ 2.17