Annual report pursuant to Section 13 and 15(d)

Net Loss per Common Share - Additional Information (Detail)

v3.19.1
Net Loss per Common Share - Additional Information (Detail) - shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 17,682,146 13,701,104
Restricted Stock [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 11,174,113 9,840,614