Annual report pursuant to Section 13 and 15(d)

Common Stock - Additional Information (Detail)

v3.8.0.1
Common Stock - Additional Information (Detail) - USD ($)
4 Months Ended 12 Months Ended
Sep. 14, 2017
Dec. 31, 2017
Dec. 31, 2017
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  
Common stock, shares issued   11,956,752 11,956,752 21,230
Gross proceeds     $ 64,000  
Stock option exercises, Shares     0 0
Restricted stock unit settlements     5,464 0
Common shares reserved for options currently outstanding   1,115,647 1,115,647  
Number of warrants exercised     0  
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   210,160 210,160  
2017 Equity Incentive Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award expiration period     10 years  
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  
2010 Performance Incentive Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award expiration period     10 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   68,507 68,507  
Common shares reserved for options currently outstanding   63,447 63,447  
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   5,060 5,060  
Minimum [Member] | Stock Options [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award expiration period     7 years  
Minimum [Member] | Stock Options [Member] | Employees and Consultants [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period     3 years  
Minimum [Member] | Stock Options [Member] | Board of Directors [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period     1 year  
Minimum [Member] | 2017 Equity Incentive Plan [Member] | Employees and Consultants [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period     3 years  
Minimum [Member] | 2017 Equity Incentive Plan [Member] | Board of Directors [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period     1 year  
Minimum [Member] | 2010 Performance Incentive Plan [Member] | Employees and Consultants [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period     3 years  
Minimum [Member] | 2010 Performance Incentive Plan [Member] | Board of Directors [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period     1 year  
Maximum [Member] | Stock Options [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award expiration period     10 years  
Maximum [Member] | Stock Options [Member] | Employees and Consultants [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period     4 years  
Maximum [Member] | Stock Options [Member] | Board of Directors [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period     3 years  
Maximum [Member] | 2017 Equity Incentive Plan [Member] | Employees and Consultants [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period     4 years  
Maximum [Member] | 2017 Equity Incentive Plan [Member] | Board of Directors [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period     3 years  
Maximum [Member] | 2010 Performance Incentive Plan [Member] | Employees and Consultants [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period     4 years  
Maximum [Member] | 2010 Performance Incentive Plan [Member] | Board of Directors [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Award vesting period     3 years  
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 123,516 873,778 873,778  
Gross proceeds $ 0      
Gross proceeds   $ 2,000,000    
Offering expenses   100,000    
Common stock available for sale under offering   $ 9,000,000 $ 9,000,000  
LPC [Member] | Minimum [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Common stock, purchase price $ 2.00      
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      
Number of warrants issued 0      
LPC [Member] | Other Units [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Number of warrants issued 0