Stockholders' Equity And Stock-Based Compensation (Schedule Of Stock-Based Compensation Expense By Plan) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 01, 2022	Mar. 26, 2021	Apr. 01, 2022	Mar. 26, 2021
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock-based compensation expense	$ 27,699	$ 24,413	$ 60,355	$ 50,726
Benefit from income taxes	(4,412)	(3,859)	(9,531)	(8,071)
Total stock-based compensation, net of tax	23,287	20,554	50,824	42,655
Stock Option [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock-based compensation expense	2,313	3,224	5,618	7,710
Restricted Stock Units (RSUs) [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock-based compensation expense	23,686	19,853	51,406	40,246
Employee Stock Purchase Plan [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock-based compensation expense	1,700	1,336	3,331	2,770
Cost of Sales [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock-based compensation expense	402	489	992	1,123
Research and Development Expense [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock-based compensation expense	9,155	7,190	19,257	15,123
Selling and Marketing Expense [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock-based compensation expense	9,791	9,110	22,039	18,906
General and Administrative Expense [Member]
Stockholders' Equity And Stock-Based Compensation [Line Items]
Stock-based compensation expense	$ 8,351	$ 7,624	$ 18,067	$ 15,574