Annual report pursuant to Section 13 and 15(d)

Subsequent Events - Additional Information (Detail)

v3.8.0.1
Subsequent Events - Additional Information (Detail) - USD ($)
Feb. 27, 2018
Aug. 01, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Subsequent Event [Line Items]          
Warrant exercise price   $ 39.82 $ 3.07 $ 3.07 $ 3.07
Subsequent Event | Term Loan Facility | Perceptive          
Subsequent Event [Line Items]          
Maximum borrowing capacity under Credit Facility $ 10,000,000        
Increase in applicable margin percentage on event of default 4.00%        
Credit Facility, quarterly amortization amount after second anniversary of closing date $ 200,000        
Credit Facility, maturity date Feb. 27, 2022        
Exit fee $ 100,000        
Subsequent Event | Term Loan Facility | Perceptive | Common Stock          
Subsequent Event [Line Items]          
Number of shares issued for each warrant 190,000        
Warrant exercisable period 7 years        
Warrant exercise price $ 9.5792        
Subsequent Event | Term Loan Facility | Perceptive | LIBOR          
Subsequent Event [Line Items]          
Debt instrument, basis spread on variable rate 11.00%        
Subsequent Event | Term Loan Facility | Perceptive | Term Loan Drawn on Effective Date of Credit Facility          
Subsequent Event [Line Items]          
Proceeds from initial term loan on closing date of Credit Facility $ 5,000,000        
Subsequent Event | Term Loan Facility | Perceptive | Additional Term Loan Drawn Six Months Following Effective Date of Credit Facility          
Subsequent Event [Line Items]          
Maximum borrowing capacity under Credit Facility $ 5,000,000