Quarterly report pursuant to Section 13 or 15(d)

Description of Business and Basis of Presentation - Additional Information (Detail)

v3.7.0.1
Description of Business and Basis of Presentation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 1 Months Ended 6 Months Ended
May 17, 2017
May 31, 2017
Mar. 31, 2017
Aug. 31, 2016
Jun. 30, 2017
May 16, 2017
Dec. 31, 2016
Organization [Line Items]              
Common stock issued         12,335,265    
Proceeds from issuance of common stock         $ 33,199    
Net book value             $ 23,350
Cash proceeds from exercise of warrants         $ 29,263    
Warrants to purchase common stock         1,277,157    
Warrants maturity period         4 years    
Bridge Loan [Member]              
Organization [Line Items]              
Accrued interest $ 45            
Warrants to purchase common stock 313,446         240,000  
Fully diluted shares outstanding percentage 1.50%            
Shares converted to common stock 590,717            
Series B Redeemable Convertible Preferred Stock [Member]              
Organization [Line Items]              
Liquidation preference value $ 18,668            
Net book value $ 18,463           17,897
Shares converted to common stock 2,309,135       2,309,135    
Series A Redeemable Convertible Preferred Stock [Member]              
Organization [Line Items]              
Liquidation preference value $ 8,598            
Net book value $ 6,272           $ 5,453
Shares converted to common stock 2,922,798       2,922,798    
Initial Public Offering [Member]              
Organization [Line Items]              
Common stock issued 2,500,000       2,500,000    
Common stock price per share $ 15.00            
Proceeds from issuance of common stock $ 32,534            
Underwriting discounts, commissions and offering costs $ 4,966            
Warrants to purchase common stock 809,400   809,400        
Warrants maturity period 5 years   5 years        
Warrant exercise price     $ 13.6088        
Convertible Notes Payable [Member] | Initial Public Offering [Member]              
Organization [Line Items]              
Warrants to purchase common stock 154,311   154,311        
Maximum [Member] | Initial Public Offering [Member]              
Organization [Line Items]              
Warrants to purchase common stock 51,437   51,437        
Acacia [Member]              
Organization [Line Items]              
Common stock issued     120,000        
Acacia [Member] | Bridge Loan [Member]              
Organization [Line Items]              
Common stock issued 90,000            
Debt instrument principal balance $ 8,000            
Borrowing under line of credit $ 4,000            
Warrants to purchase common stock 120,000            
Fully diluted shares outstanding percentage 0.75%            
Warrants maturity period 10 years            
Acacia [Member] | Initial Public Offering [Member]              
Organization [Line Items]              
Warrants to purchase common stock 809,400 809,400          
Warrants maturity period 5 years 5 years          
Warrant exercise price $ 13.6088            
Acacia [Member] | Convertible Notes Payable [Member]              
Organization [Line Items]              
Shares converted to common stock 1,523,746     1,523,746 1,523,746    
Debt instrument principal balance $ 20,000     $ 20,000      
Accrued interest $ 737            
Warrants maturity period       5 years      
Warrant exercise price       $ 13.6088      
Acacia [Member] | Primary Warrant [Member]              
Organization [Line Items]              
Issuance of stock due to warrants exercise 2,150,335   2,150,335   2,150,335    
Cash proceeds from exercise of warrants $ 29,263   $ 29,263        
Acacia [Member] | Maximum [Member] | Bridge Loan [Member]              
Organization [Line Items]              
Warrant exercise price $ 13.6088            
Acacia [Member] | Maximum [Member] | Convertible Notes Payable [Member]              
Organization [Line Items]              
Warrant exercise price     $ 13.6088        
Acacia [Member] | Maximum [Member] | Primary Warrant [Member]              
Organization [Line Items]              
Warrant exercise price     $ 13.7323