Composition Of Certain Financial Statement Captions (Schedule Of Cash, Cash Equivalents, And Investments) (Details) (USD $) In Thousands, unless otherwise specified																					3 Months Ended
	Dec. 27, 2013		Sep. 27, 2013		Dec. 27, 2013 Agency Securities [Member]		Sep. 27, 2013 Agency Securities [Member]		Dec. 27, 2013 Commercial Paper [Member]		Sep. 27, 2013 Commercial Paper [Member]		Dec. 27, 2013 Corporate Bonds [Member]		Sep. 27, 2013 Corporate Bonds [Member]		Dec. 27, 2013 Municipal Bonds [Member]		Sep. 27, 2013 Municipal Bonds [Member]		Dec. 27, 2013 Minimum [Member]	Dec. 27, 2013 Maximum [Member]
Composition Of Certain Financial Statement Captions [Line Items]
Cash	$ 475,927		$ 420,069
Cash and cash equivalents	484,640		454,397
Short-term investments	179,406		140,267		31,414		6,007		14,947		5,991		32,686		43,847		100,359		84,422
Long-term investments	293,719	[1]	306,338	[1]	21,433	[1]	40,924	[1]	4,971	[1]	0	[1]	91,267	[1]	90,391	[1]	173,048	[1]	172,023	[1]
Total cash, cash equivalents and investments	957,765		901,002
Long-term investments, maturities																					1 year	3 years
Restricted cash	$ 3,349		$ 3,175

[1] Our long-term investments have maturities that range from one to three years.