Annual report pursuant to Section 13 and 15(d)

Share-based Compensation - Summary of Activity Relating to Company's ESPP Program (Detail)

v3.6.0.2
Share-based Compensation - Summary of Activity Relating to Company's ESPP Program (Detail) - USD ($)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]    
Compensation expense $ 113,531 $ 40,233
Shares of stock sold to employees 88,109 98,070
Weighted average fair value per ESPP award $ 2.73 $ 2.73