Stock Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2017	Apr. 02, 2016
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	$ 27,436	$ 24,632
Cost of product and maintenance
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	529	464
Cost of services
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	761	681
Marketing and sales
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	6,008	5,536
Research and development
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	15,482	13,897
General and administrative
Share-based compensation expense and allocation by cost [Line Items]
Share-based Compensation	$ 4,656	$ 4,054