Commitments and Contingencies (Narrative) (Details)			3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2018 Defendent	Apr. 01, 2014 USD ($) Defendent	Sep. 28, 2018 USD ($) Case	Sep. 29, 2017 USD ($)	Sep. 28, 2018 USD ($) lawsuit Case	Sep. 29, 2017 USD ($)	Dec. 29, 2017 USD ($)	Sep. 25, 2015 order	Aug. 07, 2018 USD ($)	Mar. 25, 2016 USD ($)
Loss Contingencies [Line Items]
Litigation Settlement, Expense							$ 102,000,000.0
Payments for Legal Settlements							35,000,000.0
Environmental liabilities			$ 52,200,000		$ 52,200,000
Deferred tax liabilities related to installment sales			537,900,000		537,900,000
Section 453(a) interest			6,400,000	$ 17,600,000	18,100,000	$ 53,900,000
Interest Payable, Installment Sales			56,000,000.0		56,000,000.0		$ 46,000,000.0
Lower Passaic River, New Jersey
Loss Contingencies [Line Items]
Number of defendants | Defendent		70
Environmental liabilities			26,200,000		$ 26,200,000
Remedial cost, estimate		$ 1,700,000,000								$ 1,380,000,000
Loss Contingency, Settlement Agreement, Amount									$ 280,600
Accrual for Environmental Loss Contingencies, Period Increase (Decrease)			$ (11,800,000)
Occidental, Lower Passaic River [Member]
Loss Contingencies [Line Items]
Number of defendants | Defendent	120
Asbestos Matters
Loss Contingencies [Line Items]
Pending claims | Case			11,600		11,600
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			$ 2,400,000		$ 2,400,000
Opioid Crisis [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Plaintiffs | lawsuit					1,275
Mallinckrodt Veterinary, Inc., Millsboro, Delaware [Member]
Loss Contingencies [Line Items]
Number of Administrative Orders of Consent Entered Into | order								2
Minimum | Environmental Remediation
Loss Contingencies [Line Items]
Remedial cost, estimate			26,700,000		$ 26,700,000
Minimum | Lower Passaic River, New Jersey
Loss Contingencies [Line Items]
Remedial cost, estimate		365,000,000.0
Maximum | Environmental Remediation
Loss Contingencies [Line Items]
Remedial cost, estimate			$ 67,300,000		$ 67,300,000
Maximum | Lower Passaic River, New Jersey
Loss Contingencies [Line Items]
Remedial cost, estimate		$ 3,200,000,000