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 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense $ 4,838 $ 11,708 $ 9,963 $ 13,611
Sales and Marketing [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 246 100 814 276
Research and Development [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 596 157 1,103 261
General and Administrative [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 3,996 11,451 8,046 13,074
Employee Stock [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 228 24 517 24
Restricted Stock Units [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 130 178 277 629
Restricted Stock [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 59 125 412 250
Performance-based Stock Options [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense 1,846   1,900  
Stock Options [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]        
Stock-based compensation expense $ 2,575 $ 11,381 $ 6,857 $ 12,708