Financial Instruments and Fair Value Measurements (Schedule of Fair Value of Assets and Liabilities Measured on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 24, 2021	Dec. 25, 2020
Assets:
Other Assets, Fair Value Disclosure	$ 37.3	$ 31.1
Assets, Fair Value Disclosure	75.2	64.1
Liabilities:
Settlement Warrants, Fair Value Disclosure	0.0	0.0
Recurring
Assets:
Rabbi Trust Investments, Fair Value Disclosure	37.9	33.0
Liabilities:
Deferred Compensation Liability, Fair Value	35.9	38.0
Contingent consideration and acquired contingent liabilities	27.1	34.7
Total liabilities at fair value	63.0	72.7
Recurring | Level 1
Assets:
Rabbi Trust Investments, Fair Value Disclosure	23.7	23.5
Other Assets, Fair Value Disclosure	37.3	31.1
Assets, Fair Value Disclosure	61.0	54.6
Liabilities:
Deferred Compensation Liability, Fair Value	0.0	0.0
Contingent consideration and acquired contingent liabilities	0.0	0.0
Total liabilities at fair value	0.0	0.0
Recurring | Level 2
Assets:
Rabbi Trust Investments, Fair Value Disclosure	14.2	9.5
Other Assets, Fair Value Disclosure	0.0	0.0
Assets, Fair Value Disclosure	14.2	9.5
Liabilities:
Deferred Compensation Liability, Fair Value	35.9	38.0
Contingent consideration and acquired contingent liabilities	0.0	0.0
Total liabilities at fair value	35.9	38.0
Recurring | Level 3
Assets:
Rabbi Trust Investments, Fair Value Disclosure	0.0	0.0
Other Assets, Fair Value Disclosure	0.0	0.0
Assets, Fair Value Disclosure	0.0	0.0
Liabilities:
Deferred Compensation Liability, Fair Value	0.0	0.0
Contingent consideration and acquired contingent liabilities	27.1	34.7
Total liabilities at fair value	$ 27.1	$ 34.7