Intangible Assets and Goodwill - Schedule of Intangible Assets (Detail) - USD ($) $ in Millions	Mar. 26, 2022	Sep. 25, 2021
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 5,646.1	$ 5,582.1
Accumulated Amortization	4,093.5	3,922.9
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	4,645.2	4,597.7
Accumulated Amortization	3,329.8	3,184.2
In-process research and development
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	67.4	71.6
Accumulated Amortization	0.0	0.0
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	612.6	591.7
Accumulated Amortization	526.0	510.1
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	268.1	268.1
Accumulated Amortization	197.4	191.8
Non-competition agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	1.4	1.5
Accumulated Amortization	1.4	1.5
Business licenses
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	2.5	2.5
Accumulated Amortization	2.5	2.5
Total acquired intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	5,597.2	5,533.1
Accumulated Amortization	4,057.1	3,890.1
Internal-use software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	23.4	23.5
Accumulated Amortization	17.7	17.2
Capitalized software embedded in products
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	25.5	25.5
Accumulated Amortization	$ 18.7	$ 15.6