Annual report pursuant to Section 13 and 15(d)

Options Outstanding and Exercisable (Detail)

v3.20.1
Options Outstanding and Exercisable (Detail)
shares in Thousands
 12 Months Ended
Dec. 31, 2019
$ / shares
shares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Options Outstanding Number of Shares | shares 1,286,811
Options Outstanding Weighted Average Exercise Price $ 5.77
Options Outstanding Weighted Average Remaining Life (Years) 5 years 9 months 21 days
Options Exercisable Number of Shares | shares 1,032,872
Options Exercisable Weighted Average Exercise Price $ 6.58
$0.58 - $2.08  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices, Lower Limit 0.58
Range of Exercise Prices, Upper Limit $ 2.08
Options Outstanding Number of Shares | shares 146,186
Options Outstanding Weighted Average Exercise Price $ 1.47
Options Outstanding Weighted Average Remaining Life (Years) 8 years 10 months 20 days
Options Exercisable Number of Shares | shares 47,820
Options Exercisable Weighted Average Exercise Price $ 1.51
$2.09 - $2.65  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices, Lower Limit 2.09
Range of Exercise Prices, Upper Limit $ 2.65
Options Outstanding Number of Shares | shares 279,000
Options Outstanding Weighted Average Exercise Price $ 2.12
Options Outstanding Weighted Average Remaining Life (Years) 8 years 2 months 23 days
Options Exercisable Number of Shares | shares 151,923
Options Exercisable Weighted Average Exercise Price $ 2.11
$2.66 - $7.18  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices, Lower Limit 2.66
Range of Exercise Prices, Upper Limit $ 7.18
Options Outstanding Number of Shares | shares 281,724
Options Outstanding Weighted Average Exercise Price $ 4.74
Options Outstanding Weighted Average Remaining Life (Years) 6 years 3 months 7 days
Options Exercisable Number of Shares | shares 275,864
Options Exercisable Weighted Average Exercise Price $ 4.71
$7.19 - $8.00  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices, Lower Limit 7.19
Range of Exercise Prices, Upper Limit $ 8.00
Options Outstanding Number of Shares | shares 321,431
Options Outstanding Weighted Average Exercise Price $ 7.35
Options Outstanding Weighted Average Remaining Life (Years) 3 years 1 month 13 days
Options Exercisable Number of Shares | shares 304,530
Options Exercisable Weighted Average Exercise Price $ 7.35
$8.01 - $13.20  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices, Lower Limit 8.01
Range of Exercise Prices, Upper Limit $ 13.20
Options Outstanding Number of Shares | shares 258,470
Options Outstanding Weighted Average Exercise Price $ 11.29
Options Outstanding Weighted Average Remaining Life (Years) 4 years 3 months 7 days
Options Exercisable Number of Shares | shares 252,735
Options Exercisable Weighted Average Exercise Price $ 11.35