Quarterly report pursuant to Section 13 or 15(d)

Presentation and Summary of Significant Accounting Policies - Effect of Anti-dilutive Securities (Detail)

v3.8.0.1
Presentation and Summary of Significant Accounting Policies - Effect of Anti-dilutive Securities (Detail) - shares
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Effect of Anti-dilutive Securities 6,228,374 9,881,041
Redeemable Convertible Preferred Stock [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Effect of Anti-dilutive Securities   5,181,416
Employee Stock Option and Restricted Stock Units [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Effect of Anti-dilutive Securities 4,703,801 656,116
Warrant [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Effect of Anti-dilutive Securities 1,524,573 2,383,815
Conversion of Convertible Note Payable [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Effect of Anti-dilutive Securities   1,512,392
Bridge Loan [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Effect of Anti-dilutive Securities   147,302