Quarterly report pursuant to Section 13 or 15(d)

Stock Incentive Plan - Additional Information (Detail)

v3.10.0.1
Stock Incentive Plan - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Employee service share-based compensation, nonvested awards, compensation not yet recognized, stock options $ 0.5  
Employee service share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition 2 years  
Restricted Stock [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period 0  
Employee Stock Option [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation arrangement by share-based payment award, number of shares authorized 5,000,000  
Share price $ 3.40  
Share-based compensation arrangement by share-based payment award, options, vested in period, fair value $ 0.3 $ 0.9