Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Additional Information (Detail)

v3.8.0.1
Common Stock - Additional Information (Detail) - USD ($)
 1 Months Ended 9 Months Ended
Sep. 14, 2017
Sep. 30, 2017
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common stock, shares authorized   75,000,000 75,000,000   75,000,000
Common stock, par value   $ 0.001 $ 0.001   $ 0.001
Preferred stock, shares authorized   5,000,000 5,000,000    
Preferred stock, par value   $ 0.001 $ 0.001    
Initial purchase of units consisting of common stock and warrants issued     $ 1,129,000    
Common stock, shares issued   11,491,665 11,491,665   21,230
Stock option exercises, Shares     0 0  
Restricted stock unit settlements     3,548 0  
Common shares reserved for options currently outstanding   1,146,107 1,146,107    
Number of stock options granted     1,052,200 0  
Number of warrants exercised     0 0  
LPC [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common stock, par value $ 0.001        
Common stock value right to sell, maximum $ 11,000,000        
Initial purchase of common stock   328,947      
Common stock, purchase price $ 1.00        
Additional common stock value right to sell, maximum $ 10,000,000        
Additional purchase of common stock, maximum 80,000        
Common stock, shares issued 123,516 408,947 408,947    
Gross proceeds $ 0        
Gross proceeds   $ 1,200,000      
Offering expenses   100,000      
Common stock available for sale under offering   $ 9,800,000 $ 9,800,000    
LPC [Member] | Units [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Initial purchase of common stock 328,947        
Common stock, purchase price $ 3.04        
Purchase agreement, description     Unit consisting of (a) one share of our Common Stock and (b) one warrant to purchase one-quarter of a share of Common Stock at an exercise price of $3.496 per share, or Warrant. Each Warrant is exercisable six months following the issuance date until the date that is five years and six months after the issuance date and is subject to customary adjustments.    
Exercise price per unit of warrant $ 3.496        
Initial purchase of units consisting of common stock and warrants issued $ 1,000,000        
LPC [Member] | Other Units [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Number of warrants issued 0        
Minimum [Member] | LPC [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common stock, purchase price $ 2.00        
Stock Options [Member] | Employees and Consultants [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period     4 years    
Stock Options [Member] | Minimum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award expiration period     7 years    
Stock Options [Member] | Minimum [Member] | Board of Directors [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period     1 year    
Stock Options [Member] | Maximum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award expiration period     10 years    
Stock Options [Member] | Maximum [Member] | Board of Directors [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period     3 years    
Restricted Stock Unit [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period     4 years    
Common shares reserved for awards currently outstanding   210,416 210,416    
2010 Performance Incentive Plan [Member] | Minimum [Member] | Employees and Consultants [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period     3 years    
2010 Performance Incentive Plan [Member] | Minimum [Member] | Board of Directors [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period     1 year    
2010 Performance Incentive Plan [Member] | Maximum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award expiration period     10 years    
2010 Performance Incentive Plan [Member] | Maximum [Member] | Employees and Consultants [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period     4 years    
2010 Performance Incentive Plan [Member] | Maximum [Member] | Board of Directors [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Award vesting period     3 years    
2010 Performance Incentive Plan [Member] | Stock Options [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common shares reserved for issuance under incentive plan   304,323 304,323    
Common shares reserved for options currently outstanding   93,907 93,907    
2010 Performance Incentive Plan [Member] | Restricted Stock Unit [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common shares reserved for awards currently outstanding   210,416 210,416    
2017 Equity Incentive Plan [Member] | Stock Options [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common shares reserved for issuance under incentive plan   1,052,200 1,052,200