Goodwill and Intangible Assets Narrative (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 30, 2016	Dec. 25, 2015	Dec. 29, 2017	Sep. 30, 2016	Sep. 25, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible asset amortization	$ 175.7		$ 694.5	$ 700.1	$ 550.3
Finite-Lived Intangible Assets [Line Items]
Goodwill, Period Increase (Decrease)			(15.4)
Other Asset Impairment Charges	214.3	$ 0.0	63.7	$ 16.9	$ 0.0
Goodwill, Impaired, Accumulated Impairment Loss	207.0		207.0
Goodwill	$ 3,498.1		3,482.7
Intrathecal Therapy [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill, Written off Related to Sale of Business Unit			$ 49.8
Brands
Finite-Lived Intangible Assets [Line Items]
Weighted Average Cost of Capital, Rate			12.50%
Specialty Generics [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Cost of Capital, Rate	9.50%
Goodwill, Impaired, Accumulated Impairment Loss	$ (207.0)		$ (207.0)
Goodwill, Impairment Loss	$ 207.0
Raplixa [Member]
Finite-Lived Intangible Assets [Line Items]
Impairment of Intangible Assets, Finite-lived			$ 63.7