Stock Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	$ 40,956	$ 30,482	$ 78,857	$ 57,918
Cost of product and maintenance
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	606	491	1,196	1,020
Cost of services
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	884	717	1,747	1,478
Marketing and sales
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	8,268	6,237	15,882	12,245
Research and development
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	25,100	18,014	48,335	33,496
General and administrative
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	$ 6,098	$ 5,023	$ 11,697	$ 9,679