Stockholders' Equity And Stock-Based Compensation (Summary Of Weighted-Average Fair Value Of Stock Options Granted And Total Intrinsic Value Of Stock Options Exercised) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 30, 2016
Stockholders' Equity And Stock-Based Compensation [Abstract]
Document Period End Date	Sep. 28, 2018
Weighted-average fair value at date of grant	$ 13.19	$ 11.39	$ 8.49
Intrinsic value of options exercised	$ 63,973	$ 28,544	$ 27,485