Stockholders' Equity And Stock-Based Compensation (Schedule of Stock-Based Compensation By Classification) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jan. 01, 2016	Dec. 26, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 19,380	$ 17,842
Benefit from income taxes	(5,706)	(5,151)
Total stock-based compensation, net of tax	13,674	12,691
Cost of products [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	280	246
Cost of services [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	129	122
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	5,107	5,274
Sales and marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	7,710	5,909
General and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 6,154	$ 6,291