Stockholders' Equity And Stock-Based Compensation (Schedule of Stock-Based Compensation By Classification) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 17,101	$ 15,742	$ 53,476	$ 48,940
Benefit from income taxes	(3,488)	(4,568)	(11,041)	(14,231)
Total stock-based compensation, net of tax	13,613	11,174	42,435	34,709
Cost of products [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	249	229	756	710
Cost of services [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	151	126	411	383
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	4,859	4,551	14,486	13,987
Sales and marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	6,469	6,187	18,266	19,563
General and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 5,373	$ 4,649	$ 19,557	$ 14,297