Stock Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Apr. 01, 2017
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	$ 37,901	$ 27,436
Cost of product and maintenance
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	590	529
Cost of services
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	863	761
Marketing and sales
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	7,614	6,008
Research and development
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	23,235	15,482
General and administrative
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	$ 5,599	$ 4,656