XML 55 R44.htm IDEA: XBRL DOCUMENT v3.8.0.1
Net Loss per Share - Summary of Securities Not Included in Diluted Per Share Calculations (Detail) - shares
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities not included in the diluted per share calculations, amount 635,199 285,860
Option to purchase common stock [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities not included in the diluted per share calculations, amount 252,554 219,015
Warrants to purchase common stock [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities not included in the diluted per share calculations, amount 382,645 66,845