Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Stock Options - Additional Information (Detail)

v3.19.3
Common Stock - Stock Options - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Common shares reserved for options currently outstanding 1,010,935   1,010,935   665,585
Unrecognized compensation expense related to stock options granted $ 2.1   $ 2.1   $ 1.8
Anti-dilutive securities excluded from earning per share computation 5,137,655 3,854,505 5,137,655 3,854,505  
Warrant [Member]          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Anti-dilutive securities excluded from earning per share computation 4,116,712   4,116,712    
Stock Options [Member]          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Anti-dilutive securities excluded from earning per share computation 1,010,935   1,010,935    
Restricted Stock Unit [Member]          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Anti-dilutive securities excluded from earning per share computation 10,008   10,008    
Stock Options [Member]          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Weighted-average period, restricted stock awards     2 years 3 months 18 days    
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 10,008   10,008   15,142
Weighted-average period, restricted stock awards     1 year 10 months 2 days    
2018 Equity Incentive Plan [Member]          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Common shares reserved for issuance under incentive plan 604,055   604,055    
Award expiration period     10 years    
2018 Equity 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    
2018 Equity 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    
2018 Equity 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    
2018 Equity 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    
2018 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 1,336,055   1,336,055    
Common shares reserved for options currently outstanding 732,000   732,000    
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] | Minimum [Member] | Employees and Consultants [Member]          
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]          
Award vesting period     3 years    
2017 Equity 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    
2017 Equity 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    
2017 Equity 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    
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 272,660   272,660    
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] | 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] | 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 15,931   15,931    
Common shares reserved for options currently outstanding 5,923   5,923    
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 10,008   10,008