Goodwill and Intangible Assets (Schedule Of Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 25, 2021	Mar. 26, 2021	Jun. 26, 2020	Jun. 25, 2021	Jun. 26, 2020	Dec. 25, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Non-restructuring impairment charges	$ 0.0		$ 63.5	$ 64.5	$ 63.5
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	10,692.2			10,692.2		$ 10,592.4
Accumulated amortization	4,978.8			4,978.8		4,688.2
Intangible assets, net	5,829.4			5,829.4		6,184.5
Non-Amortizable intangible assets, gross	116.0			116.0		280.3
Non-restructuring impairment charges	0.0		$ 63.5	64.5	$ 63.5
Trademarks
Schedule of Intangible Asset by Major Class [Line Items]
Non-Amortizable intangible assets, gross	35.0			35.0		35.0
In-process Research and Development
Schedule of Intangible Asset by Major Class [Line Items]
Non-Amortizable intangible assets, gross	81.0			81.0		245.3
Completed Technology
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	10,494.4			10,494.4		10,394.6
Accumulated amortization	4,873.5			4,873.5		4,586.6
Trademarks
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	77.7			77.7		77.7
Accumulated amortization	25.2			25.2		23.5
Licensing Agreements [Member]
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	120.1			120.1		120.1
Accumulated amortization	80.1			80.1		78.1
Terlipressin [Member]
Schedule of Intangible Asset by Major Class [Line Items]
Intangible assets, net	81.0			81.0		$ 81.0
MNK-6105 [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Non-restructuring impairment charges		$ 64.5
Schedule of Intangible Asset by Major Class [Line Items]
Non-restructuring impairment charges		$ 64.5
StrataGraft [Member] | In-process Research and Development
Schedule of Intangible Asset by Major Class [Line Items]
Non-Amortizable intangible assets, gross	$ 99.8			$ 99.8