Goodwill and Intangible Assets Finite-Lived Intangible Assets (Details) - USD ($)	3 Months Ended						9 Months Ended
	Jun. 28, 2019	Mar. 29, 2019	Dec. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 29, 2017	Jun. 28, 2019	Jun. 29, 2018	Sep. 28, 2018
Finite-Lived Intangible Assets [Line Items]
Cost	$ 426,606,000						$ 426,606,000		$ 400,166,000
Accumulated Amortization	(237,302,000)						(237,302,000)		(216,147,000)
Total	189,304,000						189,304,000		184,019,000
Purchases of intangible assets	$ 10,200,000	$ 5,000,000.0	$ 12,100,000	$ 700,000	$ 2,800,000	$ 12,000,000.0	$ 27,300,000	$ 15,500,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	5 years 4 months 24 days	4 years	11 years 7 months 6 days	5 years	5 years 3 months 18 days	14 years 1 month 6 days	7 years 10 months 24 days	12 years 1 month 6 days
Amortization of Intangible Assets	$ 7,600,000			$ 6,700,000			$ 21,600,000	$ 19,800,000
Acquired Patents And Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	338,920,000						338,920,000		319,082,000
Accumulated Amortization	(170,722,000)						(170,722,000)		(152,775,000)
Total	168,198,000						168,198,000		166,307,000
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	63,223,000						63,223,000		58,342,000
Accumulated Amortization	(43,282,000)						(43,282,000)		(41,012,000)
Total	19,941,000						19,941,000		17,330,000
Other Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	24,463,000						24,463,000		22,742,000
Accumulated Amortization	(23,298,000)						(23,298,000)		(22,360,000)
Total	$ 1,165,000						$ 1,165,000		$ 382,000