Composition Of Certain Financial Statement Captions (Schedule Of Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 28, 2012	Sep. 28, 2012
Finite-Lived Intangible Assets [Line Items]
Cost	$ 131,267	$ 130,817
Accumulated Amortization	(78,354)	(74,291)
Net	52,913	56,526
Acquired Patents And Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	79,631	79,213
Accumulated Amortization	(42,886)	(40,071)
Net	36,745	39,142
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	30,693	30,679
Accumulated Amortization	(17,195)	(16,386)
Net	13,498	14,293
Other Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	20,943	20,925
Accumulated Amortization	(18,273)	(17,834)
Net	$ 2,670	$ 3,091