Stockholders' Equity - Schedule of Stock Based Compensation Expense (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	$ 31,678	$ 24,801	$ 56,792	$ 47,732
Provision for income taxes	(10,156)	(9,345)	(18,380)	(16,309)
Total stock-based compensation, net of income taxes	21,522	15,456	38,412	31,423
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	3,076	2,718	5,871	5,345
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	5,061	3,867	9,538	8,236
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	12,796	9,799	23,328	19,230
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	$ 10,745	$ 8,417	$ 18,055	$ 14,921