Quarterly report pursuant to Section 13 or 15(d)

Stock Plans - Schedule of Stock-based Compensation Expense (Detail)

v3.10.0.1
Stock Plans - Schedule of Stock-based Compensation Expense (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense $ 2,651 $ 1,778 $ 5,125 $ 1,903
Sales and Marketing [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 248 116 568 155
Research and Development [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 266 92 507 104
General and Administrative [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 2,137 1,570 4,050 1,644
Employee Stock [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 118   290  
Restricted Stock [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 135 125 353 125
Restricted Stock Units [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 99 375 147 451
Performance-based Stock Options [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 53   53  
Stock Options [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense $ 2,246 $ 1,278 $ 4,282 $ 1,327