Annual report pursuant to Section 13 and 15(d)

Stock Incentive Plan - Stock Options Outstanding Additional Information (Detail)

v3.20.1
Stock Incentive Plan - Stock Options Outstanding Additional Information (Detail) - $ / shares
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Options 1,860,722 1,980,972
Weighted Average Contractual Life Remaining 3 years 7 months 6 days  
Weighted Average Exercise Price $ 4.39  
Exercisable Options 1,248,844  
Weighted Average Grant Date Fair Value $ 4.93  
Range of Exercise Prices From $2.38 to $3.00 [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Range of Exercise Prices, Lower Limit 2.38  
Range of Exercise Prices, Upper Limit $ 3.00  
Options 357,005  
Weighted Average Contractual Life Remaining 3 years  
Weighted Average Exercise Price $ 2.43  
Exercisable Options 268,255  
Weighted Average Grant Date Fair Value $ 2.70  
Range of Exercise Prices From $3.01 to $3.28 [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Range of Exercise Prices, Lower Limit 3.01  
Range of Exercise Prices, Upper Limit $ 3.28  
Options 565,000  
Weighted Average Contractual Life Remaining 5 years 8 months 12 days  
Weighted Average Exercise Price $ 3.25  
Exercisable Options 176,500  
Weighted Average Grant Date Fair Value $ 3.25  
Range of Exercise Prices From $3.29 to $4.63 [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Range of Exercise Prices, Lower Limit 3.29  
Range of Exercise Prices, Upper Limit $ 4.63  
Options 67,750  
Weighted Average Contractual Life Remaining 5 years 4 months 24 days  
Weighted Average Exercise Price $ 3.78  
Exercisable Options 20,125  
Weighted Average Grant Date Fair Value $ 3.81  
Range of Exercise Prices From $4.64 to $4.85 [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Range of Exercise Prices, Lower Limit 4.64  
Range of Exercise Prices, Upper Limit $ 4.85  
Options 411,792  
Weighted Average Contractual Life Remaining 3 years 8 months 12 days  
Weighted Average Exercise Price $ 4.85  
Exercisable Options 324,789  
Weighted Average Grant Date Fair Value $ 4.85  
Range of Exercise Prices From $4.86 to $6.65 [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Range of Exercise Prices, Lower Limit 4.86  
Range of Exercise Prices, Upper Limit $ 6.65  
Options 10,750  
Weighted Average Contractual Life Remaining 1 year 4 months 24 days  
Weighted Average Exercise Price $ 5.68  
Exercisable Options 10,750  
Weighted Average Grant Date Fair Value $ 5.68  
Range of Exercise Prices From $6.66 to $8.76 [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Range of Exercise Prices, Lower Limit 6.66  
Range of Exercise Prices, Upper Limit $ 8.76  
Options 448,425  
Weighted Average Contractual Life Remaining 1 year 1 month 6 days  
Weighted Average Exercise Price $ 7.00  
Exercisable Options 448,425  
Weighted Average Grant Date Fair Value $ 7.00