Goodwill & Intangible Assets (Details) (USD $)	12 Months Ended
	Sep. 26, 2014	Sep. 27, 2013	Sep. 28, 2012
Goodwill [Roll Forward]
Goodwill	$ 279,724,000	$ 281,375,000
Goodwill, Translation and Purchase Accounting Adjustments	(2,150,000)	(1,651,000)
Goodwill	277,574,000	279,724,000	281,375,000
Finite-Lived Intangible Assets, Net [Abstract]
Cost	168,673,000	131,640,000
Accumulated Amortization	104,973,000	90,325,000
Net	63,700,000	41,315,000
Payments to acquire intangible assets	37,950,000	4,050,000	350,000
Amortization of intangible assets	15,100,000	15,800,000	13,200,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2015	14,378,000
2016	12,214,000
2017	9,100,000
2018	3,952,000
2019	3,414,000
Thereafter	20,642,000
Acquired patents and technology
Finite-Lived Intangible Assets, Net [Abstract]
Cost	99,262,000	79,925,000
Accumulated Amortization	61,678,000	51,267,000
Net	37,584,000	28,658,000
Payments to acquire intangible assets	(38,000,000)
Weighted-average useful life	13 years 7 months 6 days
Customer relationships
Finite-Lived Intangible Assets, Net [Abstract]
Cost	30,717,000	30,723,000
Accumulated Amortization	22,739,000	19,592,000
Net	7,978,000	11,131,000
Other intangibles
Finite-Lived Intangible Assets, Net [Abstract]
Cost	38,694,000	20,992,000
Accumulated Amortization	20,556,000	19,466,000
Net	$ 18,138,000	$ 1,526,000