XML 101 R55.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stockholders' Equity and Stock-based Compensation - Non-cash Stock-based Compensation Resulting From Restricted Stock Awards (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Non-cash stock-based compensation expense $ 38,513 $ 22,546 $ 3,010
Operating Expense [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Non-cash stock-based compensation expense 3,950 2,217 235
Sales and Marketing Expense [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Non-cash stock-based compensation expense 6,086 3,656 559
Research and Development Expense [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Non-cash stock-based compensation expense 1,912 836 104
General and Administrative Expense [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]      
Non-cash stock-based compensation expense $ 26,565 $ 15,837 $ 2,112