Annual report pursuant to Section 13 and 15(d)

Options Outstanding and Exercisable (Detail)

v3.10.0.1
Options Outstanding and Exercisable (Detail)
shares in Thousands
 12 Months Ended
Dec. 31, 2018
$ / shares
shares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Options Outstanding Number of Shares | shares 1,623
Options Outstanding Weighted Average Exercise Price $ 6.54
Options Outstanding Weighted Average Remaining Life (Years) 5 years 11 months 8 days
Options Exercisable Number of Shares | shares 1,101
Options Exercisable Weighted Average Exercise Price $ 7.88
Range One  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices, Lower Limit 1.17
Range of Exercise Prices, Upper Limit $ 2.13
Options Outstanding Number of Shares | shares 416
Options Outstanding Weighted Average Exercise Price $ 1.95
Options Outstanding Weighted Average Remaining Life (Years) 9 years 2 months 8 days
Options Exercisable Number of Shares | shares 105
Options Exercisable Weighted Average Exercise Price $ 2.10
Range Two  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices, Lower Limit 2.14
Range of Exercise Prices, Upper Limit $ 6.57
Options Outstanding Number of Shares | shares 273
Options Outstanding Weighted Average Exercise Price $ 4.06
Options Outstanding Weighted Average Remaining Life (Years) 7 years 2 months 12 days
Options Exercisable Number of Shares | shares 204
Options Exercisable Weighted Average Exercise Price $ 4.30
Range Three  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices, Lower Limit 6.58
Range of Exercise Prices, Upper Limit $ 7.50
Options Outstanding Number of Shares | shares 391
Options Outstanding Weighted Average Exercise Price $ 7.17
Options Outstanding Weighted Average Remaining Life (Years) 3 years 21 days
Options Exercisable Number of Shares | shares 320
Options Exercisable Weighted Average Exercise Price $ 7.16
Range Four  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices, Lower Limit 7.51
Range of Exercise Prices, Upper Limit $ 11.10
Options Outstanding Number of Shares | shares 283
Options Outstanding Weighted Average Exercise Price $ 9.15
Options Outstanding Weighted Average Remaining Life (Years) 6 years 3 months 25 days
Options Exercisable Number of Shares | shares 213
Options Exercisable Weighted Average Exercise Price $ 9.43
Range Five  
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]  
Range of Exercise Prices, Lower Limit 11.11
Range of Exercise Prices, Upper Limit $ 20.35
Options Outstanding Number of Shares | shares 260
Options Outstanding Weighted Average Exercise Price $ 12.69
Options Outstanding Weighted Average Remaining Life (Years) 3 years 3 months 18 days
Options Exercisable Number of Shares | shares 259
Options Exercisable Weighted Average Exercise Price $ 12.69