Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Related Party Transactions - Additional Information (Detail)

v3.10.0.1
Related Party Transactions - Additional Information (Detail) - USD ($)
12 Months Ended
Jun. 01, 2018
May 25, 2017
Nov. 04, 2016
Apr. 20, 2016
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
May 03, 2010
Related Party Transaction [Line Items]                  
Fair value of options         $ 5,500,000 $ 3,600,000 $ 2,200,000    
Common stock, fair value (in dollars per share)         $ 2.67 $ 2.29      
Options, grants in period, grant price (in dollars per share)         $ 2.80        
Executive Vice President                  
Related Party Transaction [Line Items]                  
Number of securities called by warrants or rights (in shares)                 450,000
Related party transaction, expenses from transactions with related party         $ 163,000 $ 242,000 263,000    
Payment of annual bonus compensation         58,013 31,912 85,000    
Related party transaction, compensation for services on board         $ 50,000 $ 50,000 $ 0    
Common stock shares granted (in shares) 3,017 10,000   100,000          
Fair value of options $ 11,284 $ 24,700   $ 250,000          
Common stock, fair value (in dollars per share) $ 3.74 $ 2.47   $ 2.50          
Options, grants in period, grant price (in dollars per share) $ 11.60 $ 7.27   $ 7.15          
Executive Vice President | November Four Two Thousand Sixteen Through April Thirty Two Thousand Twenty                  
Related Party Transaction [Line Items]                  
Annual cash bonus percentage     35.00%            
Compensation bonus target percentage     150.00%            
Executive Vice President | November Four Two Thousand Sixteen Through April Thirty Two Thousand Twenty | Until April 2017                  
Related Party Transaction [Line Items]                  
Retainer compensation     $ 21,666            
Executive Vice President | November Four Two Thousand Sixteen Through April Thirty Two Thousand Twenty | May 2017 Until April 2018                  
Related Party Transaction [Line Items]                  
Retainer compensation     15,000            
Executive Vice President | November Four Two Thousand Sixteen Through April Thirty Two Thousand Twenty | May 2018 Until April 2019                  
Related Party Transaction [Line Items]                  
Retainer compensation     12,500            
Executive Vice President | November Four Two Thousand Sixteen Through April Thirty Two Thousand Twenty | Thereafter                  
Related Party Transaction [Line Items]                  
Retainer compensation     $ 10,000            
Restricted Stock                  
Related Party Transaction [Line Items]                  
Restricted common stock shares granted (in shares)         87,811 372,711 43,332    
Restricted stock, fair value per share (in dollars per share)         $ 9.01 $ 7.27 $ 3.59 $ 3.10  
Restricted Stock | Executive Vice President                  
Related Party Transaction [Line Items]                  
Restricted common stock shares granted (in shares) 6,897 8,667              
Fair value of restricted stock $ 80,005 $ 63,009              
Restricted stock, fair value per share (in dollars per share) $ 11.60 $ 7.27