Stockholders' Equity - Schedule of Stock Based Compensation Expense (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	$ 25,114	$ 22,931
Provision for income taxes	(8,224)	(6,964)
Total stock-based compensation, net of income taxes	16,890	15,967
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	2,795	2,627
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	4,477	4,369
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	10,532	9,431
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	$ 7,310	$ 6,504