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. 30, 2016	Sep. 25, 2015	Sep. 26, 2014
Stockholders' Equity And Stock-Based Compensation [Abstract]
Document Period End Date	Sep. 30, 2016
Weighted-average fair value at date of grant	$ 8.49	$ 10.54	$ 11.11
Intrinsic value of options exercised	$ 27,485	$ 8,546	$ 15,300