Composition Of Certain Financial Statement Captions (Schedule Of Gross Unrealized Losses And The Fair Value For Available-For-Sale Securities) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 27, 2013	Sep. 27, 2013
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 months	$ 143,289	$ 147,242
Gross Unrealized Losses, Less than 12 months	(321)	(407)
Fair Value, 12 months or greater	0	0
Gross Unrealized Losses, 12 months or greater	0	0
Fair Value	143,289	147,242
Gross Unrealized Losses	(321)	(407)
Agency Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 months	26,930	21,407
Gross Unrealized Losses, Less than 12 months	(52)	(76)
Fair Value	26,930	21,407
Gross Unrealized Losses	(52)	(76)
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 months	50,145	53,350
Gross Unrealized Losses, Less than 12 months	(158)	(174)
Gross Unrealized Losses, 12 months or greater	0
Fair Value	50,145	53,350
Gross Unrealized Losses	(158)	(174)
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 months	66,214	72,485
Gross Unrealized Losses, Less than 12 months	(111)	(157)
Fair Value, 12 months or greater	0	0
Gross Unrealized Losses, 12 months or greater	0	0
Fair Value	66,214	72,485
Gross Unrealized Losses	$ (111)	$ (157)