Acquisitions and License Agreements (Schedule of Intangible Asset Amortization by Acquiree) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 25, 2015	Sep. 26, 2014
Schedule of Intangible Asset Amortization by Acquiree [Line Items]
Intangible asset amortization	$ 700.1	$ 550.3	$ 154.8
Therakos
Schedule of Intangible Asset Amortization by Acquiree [Line Items]
Intangible asset amortization	78.0	0.0	0.0
Total Acquisitions
Schedule of Intangible Asset Amortization by Acquiree [Line Items]
Intangible asset amortization	665.7	521.0	120.8
Ikaria
Schedule of Intangible Asset Amortization by Acquiree [Line Items]
Intangible asset amortization	124.5	57.1	0.0
Questcor Pharmaceuticals, Inc.
Schedule of Intangible Asset Amortization by Acquiree [Line Items]
Intangible asset amortization	300.7	301.4	34.9
Cadence Pharmaceuticals, Inc.
Schedule of Intangible Asset Amortization by Acquiree [Line Items]
Intangible asset amortization	162.5	162.5	85.9
Cost of Sales
Schedule of Intangible Asset Amortization by Acquiree [Line Items]
Amortization Of Inventory Step-Up To Cost Of Sales	$ 24.3	$ 44.1	$ 25.7