Condensed Consolidated Statements of Operations Parenthetical - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Cost of revenues    
Stock-based Compensation Expense $ 2,987 $ 2,577
Sales and marketing    
Stock-based Compensation Expense 20,015 18,092
Research and development    
Stock-based Compensation Expense 25,157 23,515
General and administrative    
Stock-based Compensation Expense $ 7,604 $ 5,011