Commitments and Contingencies (Narrative) (Details)		1 Months Ended		3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 26, 2012 action	Aug. 31, 2013 lawsuit Case	Aug. 31, 2012 principal	Dec. 30, 2016 USD ($)	Jun. 26, 2015 USD ($)	Dec. 29, 2017 USD ($) lawsuit Case	Sep. 30, 2016 USD ($) Defendent	Sep. 25, 2015 USD ($) Defendent order	Apr. 11, 2014 USD ($)	Mar. 28, 2014 USD ($)
Loss Contingencies [Line Items]
Payments for Legal Settlements						$ 35,000,000
Litigation Settlement, Expense				$ 102,000,000
Environmental liabilities						75,400,000
Plant Assets Exchanged for Industrial Revenue Bonds						16,000,000
Deferred Tax Liabilities Installment Sales				1,801,400,000		553,600,000
Increase (Decrease) Deferred Tax Liability Resulting From Legal Reorganization						679,300,000
Increase (Decrease) Deferred Tax Liability Resulting From Tax Reform						351,800,000
Increase (Decrease) Deferred Tax Liability Resulting from Installment Note Payments						(270,600,000)
Interest Expense, Installment Sales				15,900,000		69,300,000	$ 73,800,000	$ 36,500,000
Installment note deferred asset write off, net						8,400,000
Interest Payable, Installment Sales				30,300,000		46,000,000
Rent expense				7,200,000		30,400,000	$ 23,900,000	22,200,000
Tax Matters Agreement | Covidien
Loss Contingencies [Line Items]
Tax agreement, tax threshold						$ 200,000,000
Lower Passaic River, New Jersey
Loss Contingencies [Line Items]
Number of defendants | Defendent							98
Environmental liabilities										$ 13,300,000
Remedial cost, estimate							$ 1,380,000,000
Asbestos Matters
Loss Contingencies [Line Items]
Pending claims | Case						11,600
Estimation of liability, historical term						5 years
Estimation of liability, expected future term of claims						7 years
Other current liabilities
Loss Contingencies [Line Items]
Environmental liabilities, current						$ 2,200,000
opioid crisis [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Plaintiffs | lawsuit						262
Loss contingency, number of plaintiffs, state court						18
Retrophin Litigation [Member]
Loss Contingencies [Line Items]
Litigation Settlement, Expense								$ 15,500,000
Glenridge Litigation
Loss Contingencies [Line Items]
Number of defendants | principal			3
Loss Contingency, Lawsuits, Number | lawsuit		2
Pending claims | Case		1
Questcor Securities Litigation [Member]
Loss Contingencies [Line Items]
Filed-actions consolidated into the lawsuit | action	4
Litigation Settlement, Amount (Deprecated 2017-01-31)					$ 38,000,000
Loss Contingency, Accrual, Current					$ 38,000,000
Mallinckrodt Veterinary, Inc., Millsboro, Delaware
Loss Contingencies [Line Items]
Number of Administrative Orders of Consent Entered Into | order								2
Lower Passaic River, New Jersey
Loss Contingencies [Line Items]
Number of defendants | Defendent								70
Environmental liabilities									$ 23,100,000
Remedial cost, estimate									1,700,000,000
Intrathecal Therapy [Member]
Loss Contingencies [Line Items]
Increase (Decrease) Deferred Tax Liability Resulting From Installment Sale Transaction						$ 53,900,000
Minimum
Loss Contingencies [Line Items]
Remedial cost, estimate						37,600,000
Minimum | Lower Passaic River, New Jersey
Loss Contingencies [Line Items]
Remedial cost, estimate								$ 483,400,000	365,000,000
Maximum
Loss Contingencies [Line Items]
Remedial cost, estimate						$ 115,500,000
Maximum | Lower Passaic River, New Jersey
Loss Contingencies [Line Items]
Remedial cost, estimate								$ 2,700,000,000	$ 3,200,000,000
Recurring | Level 3 | Stratatech [Member]
Loss Contingencies [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability				$ 55,700,000			$ 53,500,000