Goodwill and Intangible Assets (Schedule Of Intangible Assets) (Details) - USD ($) $ in Millions	Mar. 27, 2020	Dec. 27, 2019
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	$ 10,654.7	$ 10,654.7
Accumulated amortization	4,114.6	3,917.0
Non-Amortizable intangible assets, gross	280.3	280.3
Trademarks
Schedule of Intangible Asset by Major Class [Line Items]
Non-Amortizable intangible assets, gross	35.0	35.0
In-process Research and Development
Schedule of Intangible Asset by Major Class [Line Items]
Non-Amortizable intangible assets, gross	245.3	245.3
Completed Technology
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	10,456.9	10,456.9
Accumulated amortization	4,018.5	3,822.8
Trademarks
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	77.7	77.7
Accumulated amortization	21.0	20.1
Licensing Agreements [Member]
Schedule of Intangible Asset by Major Class [Line Items]
Amortizable intangible assets, gross	120.1	120.1
Accumulated amortization	$ 75.1	$ 74.1