Goodwill and Intangible Assets - Gross Carrying Amount and Accumulated Amortization of Intangible Assets (Detail) - USD ($) $ in Millions	Sep. 27, 2019	Sep. 28, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	$ 408.7	$ 191.1
Accumulated amortization	(120.7)	(98.8)
Net carrying amount	288.0	92.3
In-process R&D with indefinite lives	12.7	8.8
Intangible assets, gross carrying amount	421.4	199.9
Intangible assets, net carrying amount	300.7	101.1
Technologies and patents
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	226.4	136.2
Accumulated amortization	(85.9)	(72.6)
Net carrying amount	140.5	63.6
Customer contracts, supplier relationships and partner relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	121.1	44.9
Accumulated amortization	(25.7)	(19.1)
Net carrying amount	95.4	25.8
Trade Names
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	55.1	3.4
Accumulated amortization	(3.0)	(1.3)
Net carrying amount	52.1	2.1
Other
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying amount	6.1	6.6
Accumulated amortization	(6.1)	(5.8)
Net carrying amount	$ 0.0	$ 0.8