Goodwill and Intangible Assets (Schedule Of Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 25, 2020	Dec. 27, 2019
Schedule of Intangible Asset by Major Class [Line Items]
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)			$ 388.0
Other Asset Impairment Charges	$ 154.9	$ 63.5	388.0
Intangible asset amortization	581.1	771.2	853.4
Amortizable:
Finite-lived intangible assets, gross	10,601.8	10,592.4
Accumulated amortization	5,269.4	4,688.2
Non-Amortizable:
Indefinite-lived intangible assets, gross	116.0	280.3
Asset Impairment Charges	154.9	63.5	388.0
Trademarks
Non-Amortizable:
Indefinite-lived intangible assets, gross	35.0	35.0
In-process research and development
Non-Amortizable:
Indefinite-lived intangible assets, gross	81.0	245.3
VTS-270 [Member]
Schedule of Intangible Asset by Major Class [Line Items]
Other Asset Impairment Charges			274.5
Stannsoporfin [Member]
Schedule of Intangible Asset by Major Class [Line Items]
Other Asset Impairment Charges			$ 113.5
Completed Technology
Amortizable:
Finite-lived intangible assets, gross	10,404.0	10,394.6
Accumulated amortization	5,160.4	4,586.6
Licensing Agreements
Amortizable:
Finite-lived intangible assets, gross	120.1	120.1
Accumulated amortization	82.1	78.1
Trademarks
Amortizable:
Finite-lived intangible assets, gross	77.7	77.7
Accumulated amortization	$ 26.9	$ 23.5