Financial Instruments and Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 30, 2018	Mar. 16, 2018	Dec. 29, 2017	Dec. 11, 2017	Apr. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Notes receivable	$ 0.0		$ 154.0
Business Combination, Contingent Consideration, Liability, Current	52.2
Business Combination, Contingent Consideration, Liability, Noncurrent	169.8
Mesoblast [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available-for-sale Securities, Sold at Par	3.4
Proceeds from Sale of Available-for-sale Securities, Equity	4.3
Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds	0.9
Available-for-sale Securities, Gross Unrealized Gain (Loss)	0.5
Senior Notes | 3.50% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Stated interest rate					3.50%
Senior Notes | 4.75% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Stated interest rate					4.75%
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investments, Fair Value Disclosure	35.3		35.4
PreveLeak | Hemostasis Products
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Business Combination, Contingent Consideration, Payment	12.0
Level 3 | Other Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash surrender value of life insurance	66.7		67.0
Level 3 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investments, Fair Value Disclosure	0.0		0.0
Level 3 | Recurring | Questcor Pharmaceuticals, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of contingent liability	113.1		111.8
Level 3 | Recurring | Stratatech
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of contingent liability	53.0		53.5
Level 3 | Raplixa | Recurring | Hemostasis Products
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of contingent consideration			7.0
Level 3 | PreveLeak | Recurring | Hemostasis Products
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of contingent liability			17.1
Level 3 | Stannsoporfin [Member] | Recurring | InfaCare Acquisition
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of contingent consideration	34.5		35.0
Level 3 | MNK-6105 [Member] | Recurring | Ocera [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Fair value of contingent consideration	$ 21.4			$ 22.0
Level 2 | Debentures | 8.00% Debenture
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Stated interest rate	8.00%
Level 2 | Debentures | 9.50% Debenture
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Stated interest rate	9.50%
Level 2 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investments, Fair Value Disclosure	$ 10.9		11.4
Level 1 | Senior Notes | 3.50% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Stated interest rate	3.50%
Level 1 | Senior Notes | 4.75% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Stated interest rate	4.75%
Level 1 | Senior Notes | 5.75% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Stated interest rate	5.75%
Level 1 | Senior Notes | 4.88% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Stated interest rate	4.875%
Level 1 | Senior Notes | 5.50% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Stated interest rate	5.50%
Level 1 | Unsecured Debt | 5.625% Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Stated interest rate	5.625%
Level 1 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investments, Fair Value Disclosure	$ 24.4		24.0
Maximum | Synacthen | Questcor Pharmaceuticals, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Milestone Payment	140.0
Specialty Generics Disposal Group
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Disposal Group, Not Discontinued Operation, Contingent Consideration		$ 12.1
Indemnification Agreement | Mallinckrodt Baker | Level 1 | Other Assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Restricted Cash and Cash Equivalents	$ 18.3		$ 18.3