Annual report pursuant to Section 13 and 15(d)

Net Loss per Common Share - Computations of Diluted Weighted Average Shares Outstanding (Detail)

v3.8.0.1
Net Loss per Common Share - Computations of Diluted Weighted Average Shares Outstanding (Detail) - shares
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total of weighted average shares outstanding 13,701,104 13,676,979 9,889,452
Warrants to Purchase Common Stock [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total of weighted average shares outstanding 745,285 456,150 685,061
Opus warrants to purchase Common Stock [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total of weighted average shares outstanding 628,383 1,780,000 0
Options to Purchase Common Stock [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total of weighted average shares outstanding 1,093,283 1,604,214 1,960,443
Unvested Restricted Stock [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total of weighted average shares outstanding 9,840,614 8,749,052 6,816,321
Unvested Restricted Stock Units [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total of weighted average shares outstanding 1,390,799 1,087,563 427,627
Series A Preferred Stock      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Total of weighted average shares outstanding 2,740 0 0