Stock-Based Compensation - Schedule of Stock Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	$ 183,813	$ 164,308	$ 144,506
Provision for income taxes	(48,502)	(56,237)	(49,014)
Total stock-based compensation, net of taxes	135,311	108,071	95,492
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	21,892	20,314	18,287
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	44,034	38,864	29,739
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	64,373	60,246	55,407
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	$ 53,514	$ 44,884	$ 41,073