Financial Instruments and Fair Value Measurements (Narrative) (Details) CAD in Millions, $ in Millions	12 Months Ended
	Dec. 29, 2017 USD ($)	Sep. 30, 2016 CAD	Sep. 25, 2015 CAD	Dec. 11, 2017 USD ($)	Sep. 25, 2017 USD ($)	Dec. 30, 2016 USD ($)	Sep. 30, 2016 USD ($)	Aug. 31, 2016 USD ($)	Feb. 01, 2016 USD ($)	Aug. 31, 2014 USD ($)	Apr. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability, Current	$ 64.0
Business Combination, Contingent Consideration, Liability, Noncurrent	182.4
Notes, Loans and Financing Receivable, Net, Current	154.0					$ 0.0
Novartis 2015 and 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Annual Payments	25.0
Novartis, Subsequent to 2016 till FDA Approval
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Annual Payments	25.0
Novartis, Subsequent to FDA Approval
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Potential Payment	25.0
Questcor Pharmaceuticals, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Maximum contingent payments for acquisition	$ 140.0
Discount rate	4.70%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability	$ 111.8					124.7				$ 195.4
Hemostasis Products
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent consideration upon acquisition									$ 52.0
Maximum contingent payments for acquisition									$ 395.0
Stratatech [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent consideration upon acquisition								$ 54.9
Maximum contingent payments for acquisition								$ 121.0
InfaCare [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent consideration upon acquisition					$ 35.0
Maximum contingent payments for acquisition					$ 345.0
Ocera [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent consideration upon acquisition				$ 22.0
Maximum contingent payments for acquisition				75.0
4.00% term loan due February 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	4.00%
Debentures | 8.00% debentures due March 2023 | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	8.00%
Debentures | 9.50% debentures due May 2022 | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	9.50%
Senior Notes | 3.50% notes due April 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate											3.50%
Senior Notes | 3.50% notes due April 2018 | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	3.50%
Senior Notes | 4.75% notes due April 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate											4.75%
Senior Notes | 4.75% notes due April 2023 | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	4.75%
Senior Notes | 5.75% notes due August 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	5.75%
Stated interest rate										5.75%
Debentures | Four Point Eight Eight Percent Notes [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	4.875%
Debentures | Five Point Five Percent Notes [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	5.50%
Debentures | 5.625% notes due October 2023 | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate	5.625%
Carrying Value | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash	$ 18.3					19.1
Carrying Value | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash surrender value of life insurance	67.0					67.6
BioVectra Inc [Member] | Questcor Pharmaceuticals, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent consideration upon acquisition | CAD			CAD 50.0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements | CAD		CAD 40.0	CAD 5.0
Raplixa [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Fair Value Adjustment	54.6
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent consideration upon acquisition	246.4					250.5
Debt and equity securities held in rabbi trusts	35.4					33.6
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent consideration upon acquisition	0.0					0.0
Debt and equity securities held in rabbi trusts	24.0					22.8
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent consideration upon acquisition	0.0					0.0
Debt and equity securities held in rabbi trusts	11.4					10.8
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent consideration upon acquisition	246.4					250.5
Debt and equity securities held in rabbi trusts	0.0					0.0
Recurring | Level 3 | Stratatech [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability						55.7	$ 53.5
Recurring | PreveLeak [Member] | Level 3 | Hemostasis Products
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability	17.1					11.2
Recurring | Raplixa [Member] | Level 3 | Hemostasis Products
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent consideration upon acquisition	7.0					58.9
Recurring | Stannsoporfin [Member] | Level 3 | InfaCare [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent consideration upon acquisition	35.0
Recurring | MNK-6105 [Member] | Level 3 | Ocera [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of contingent consideration upon acquisition				$ 22.0
Contingent Consideration | Recurring | Questcor Pharmaceuticals, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value						250.5
Contingent Consideration | Recurring | Total Acquisitions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	246.4
Other Assets | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and equity securities held in rabbi trusts	$ 0.0					$ 11.1