Summary of Significant Accounting Policies - Schedule of Intangible Assets (Detail) - USD ($) $ in Millions	Sep. 24, 2016	Sep. 26, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 5,324.9	$ 5,322.8
Accumulated Amortization	2,681.5	2,299.6
Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	3,983.7	3,979.1
Accumulated Amortization	1,991.6	1,698.5
In-process Research and Development [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	3.7	3.7
Accumulated Amortization	0.0	0.0
Customer Relationships and Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	1,098.9	1,101.1
Accumulated Amortization	546.2	467.5
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	236.2	236.4
Accumulated Amortization	141.6	131.5
Business Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	2.4	2.5
Accumulated Amortization	$ 2.1	$ 2.1