Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Additional Information (Detail)

v3.10.0.1
Stockholders' Equity - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 1 Months Ended 6 Months Ended
Jun. 30, 2018
Nov. 30, 2017
May 31, 2017
Jun. 30, 2018
Jun. 30, 2017
Dec. 31, 2017
Class of Stock [Line Items]            
Net proceeds from stock issuance       $ 32,536 $ 33,199  
Warrants outstanding 1,297,151     1,297,151   1,524,573
Warrants canceled 247,422          
Follow-on Offering [Member]            
Class of Stock [Line Items]            
Common stock shares issued 1,955,000 1,121,250        
Share price $ 18.00 $ 23.00   $ 18.00    
Net proceeds from stock issuance $ 32,890 $ 23,789        
Stock issuance costs $ 2,300 $ 2,000        
Initial Public Offering [Member]            
Class of Stock [Line Items]            
Common stock shares issued     2,500,000      
Share price     $ 15.00      
Net proceeds from stock issuance     $ 32,600      
Stock issuance costs     $ 4,900      
Series A Redeemable Convertible Preferred Stock [Member]            
Class of Stock [Line Items]            
Shares converted to common stock       2,922,978    
Series B Redeemable Convertible Preferred Stock [Member]            
Class of Stock [Line Items]            
Shares converted to common stock       2,309,135    
Acacia [Member] | Initial Public Offering [Member]            
Class of Stock [Line Items]            
Common stock shares issued     2,150,335      
Net proceeds from stock issuance     $ 29,263      
Acacia [Member] | Line of Credit [Member] | Initial Public Offering [Member]            
Class of Stock [Line Items]            
Debt instrument outstanding balance     $ 8,000      
Debt instrument converted to common stock     590,717      
Conversion price per share     $ 13.6088      
Acacia [Member] | Primary Warrant [Member] | Initial Public Offering [Member]            
Class of Stock [Line Items]            
Issuance of stock due to warrants exercise     154,311      
Warrants exercise price per share     $ 13.6088      
Acacia [Member] | Convertible Notes Payable [Member] | Initial Public Offering [Member]            
Class of Stock [Line Items]            
Debt instrument outstanding balance     $ 20,000      
Debt instrument converted to common stock     1,523,746      
Conversion price per share     $ 13.6088