Commitments and Contingencies (Narrative) (Details) $ in Millions			1 Months Ended	3 Months Ended		9 Months Ended			12 Months Ended
	Apr. 01, 2014 USD ($) Defendent	Sep. 26, 2012 action	Aug. 31, 2012 principal	Sep. 29, 2017 USD ($) Case	Sep. 30, 2016 USD ($)	Sep. 29, 2017 USD ($) Defendent Case order	Sep. 30, 2016 USD ($)	Jun. 26, 2015 USD ($)	Sep. 25, 2015 USD ($)	Dec. 30, 2016 USD ($)	Mar. 25, 2016 USD ($)	Mar. 27, 2015 USD ($)	Mar. 28, 2014 USD ($)	Aug. 31, 2013 Case
Loss Contingencies [Line Items]
Payments for Legal Settlements				$ 35.0
Environmental liabilities				75.5		$ 75.5
Deferred tax liabilities related to installment sales				1,606.7		1,606.7
Section 453(a) interest				17.6	$ 17.4	53.9	$ 55.1
Interest Payable, Installment Sales				$ 42.9		$ 42.9				$ 30.3
Lower Passaic River, New Jersey
Loss Contingencies [Line Items]
Number of defendants | Defendent	70					98
Environmental liabilities												$ 13.3	$ 23.1
Remedial cost, estimate	$ 1,700.0										$ 1,380.0
Asbestos Matters
Loss Contingencies [Line Items]
Pending claims | Case				11,500		11,500
Estimation of liability, historical term						5 years
Estimation of liability, expected future term of claims						7 years
Accrued and other current liabilities
Loss Contingencies [Line Items]
Environmental liabilities, current				$ 2.4		$ 2.4
Questcor Acquisition of Synacthen [Member]
Loss Contingencies [Line Items]
Litigation Settlement, Expense						$ 102.0
Retrophin Litigation [Member]
Loss Contingencies [Line Items]
Litigation Settlement, Expense									$ 15.5
Glenridge Litigation
Loss Contingencies [Line Items]
Number of defendants | principal			3
Pending claims | Case														1
Questcor Securities Litigation
Loss Contingencies [Line Items]
Subsequent actions consolidated into lawsuit | action		4
Litigation Settlement, Amount								$ 38.0
Loss Contingency Accrual								$ 38.0
Mallinckrodt Veterinary, Inc., Millsboro, Delaware [Member]
Loss Contingencies [Line Items]
Number of Administrative Orders of Consent Entered Into | order						2
Industrial Revenue Bonds
Loss Contingencies [Line Items]
Plant assets exchanged for IRBs						$ 16.0
Minimum | Environmental Remediation
Loss Contingencies [Line Items]
Remedial cost, estimate				37.8		37.8
Minimum | Lower Passaic River, New Jersey
Loss Contingencies [Line Items]
Remedial cost, estimate	365.0			483.4		483.4
Maximum | Environmental Remediation
Loss Contingencies [Line Items]
Remedial cost, estimate				114.2		114.2
Maximum | Lower Passaic River, New Jersey
Loss Contingencies [Line Items]
Remedial cost, estimate	$ 3,200.0			$ 2,700.0		$ 2,700.0